diff --git a/tools/gfx.py b/tools/gfx.py deleted file mode 100755 index a3d955627..000000000 --- a/tools/gfx.py +++ /dev/null @@ -1,267 +0,0 @@ -#!/usr/bin/env python2 -# -*- coding: utf-8 -*- - -"""Supplementary scripts for graphics conversion.""" - -import os -import argparse - -from pokemontools import gfx, lz - - -# Graphics with inverted tilemaps that aren't covered by filepath_rules. -pics = [ - 'gfx/shrink1', - 'gfx/shrink2', -] - -def recursive_read(filename): - def recurse(filename_): - lines = [] - for line in open(filename_): - if 'include "' in line.lower(): - lines += recurse(line.split('"')[1]) - else: - lines += [line] - return lines - lines = recurse(filename) - return ''.join(lines) - -base_stats = None -def get_base_stats(): - global base_stats - if not base_stats: - base_stats = recursive_read('data/base_stats.asm') - return base_stats - -def get_pokemon_dimensions(path): - try: - byte = bytearray(open(path, 'rb').read())[0] - width = byte & 0xf - height = (byte >> 8) & 0xf - return width, height - except: - return None - - -def get_animation_frames(path=None, w=7, h=7, bitmask_path=None, frame_path=None): - """Retrieve animation frame tilemaps from generated frame/bitmask data.""" - if not path: - path = bitmask_path - if not path: - path = frame_path - if not path: - raise Exception("need at least one of path, bitmask_path or frame_path") - - if not bitmask_path: - bitmask_path = os.path.join(os.path.split(path)[0], 'bitmask.asm') - if not frame_path: - frame_path = os.path.join(os.path.split(path)[0], 'frames.asm') - bitmask_lines = open(bitmask_path).readlines() - frame_lines = open(frame_path).readlines() - - bitmask_length = w * h - - bitmasks = [] - bitmask = [] - for line in bitmask_lines: - if '\tdb ' in line: - value = line.split('\tdb ')[1].strip().replace('%', '0b') - value = int(value, 0) - #print line.strip(), value, len(bitmasks), len(bitmask) - for bit in xrange(8): - bitmask += [(value >> bit) & 1] - if len(bitmask) >= bitmask_length: - bitmasks += [bitmask] - bitmask = [] - break - if bitmask: - bitmasks += [bitmask] - - frames = [] - frame_labels = [] - i = 0 - for line in frame_lines: - if '\tdw ' in line: - frame_labels += [line.split('\tdw ')[1].strip()] - else: - for part in line.split(): - part = part.strip() - if part in frame_labels: - frames += [(part, i)] - i += 1 - - results = [] - - for label, i in frames: - result = [] - - # get the bitmask and tile ids for each frame - # don't care if we read past bounds, so just read the rest of the file - values = [] - for line in frame_lines[i:]: - if '\tdb ' in line: - values += line.split('\tdb ')[1].split(';')[0].split(',') - - #print bitmasks - #print values[0] - #print int(values[0].replace('$', '0x'), 0) - bitmask = bitmasks[int(values[0].replace('$', '0x'), 0)] - tiles = values[1:] - k = 0 - j = 0 - for bit in bitmask: - if bit: - result += [int(tiles[k].replace('$', '0x'), 0)] - k += 1 - else: - result += [j] - j += 1 - - results += [result] - - return results - -def get_animated_graphics(path, w=7, h=7, bitmask_path=None, frame_path=None): - frames = get_animation_frames(path, w, h, bitmask_path, frame_path) - new_path = path.replace('.animated.2bpp', '.2bpp') - tiles = gfx.get_tiles(bytearray(open(path, 'rb').read())) - new_tiles = tiles[:w * h] - for frame in frames: - for tile in frame: - new_tiles += [tiles[tile]] - new_graphic = gfx.connect(new_tiles) - print new_path, list(new_graphic) - open(new_path, 'wb').write(bytearray(new_graphic)) - return new_path - -def filepath_rules(filepath): - """Infer attributes of certain graphics by their location in the filesystem.""" - args = {} - - filedir, filename = os.path.split(filepath) - if filedir.startswith('./'): - filedir = filedir[2:] - - name, ext = os.path.splitext(filename) - if ext == '.lz': - name, ext = os.path.splitext(name) - - pokemon_name = '' - - if 'gfx/pokemon/' in filedir: - pokemon_name = filedir.split('/')[-1] - if pokemon_name.startswith('unown_'): - index = filedir.find(pokemon_name) - if index != -1: - filedir = filedir[:index + len('unown')] + filedir[index + len('unown_a'):] - if name == 'front' or name == 'front.animated': - args['pal_file'] = os.path.join(filedir, 'normal.pal') - args['pic'] = True - args['animate'] = True - elif name == 'back': - args['pal_file'] = os.path.join(filedir, 'normal.pal') - args['pic'] = True - - elif 'gfx/trainers' in filedir: - args['pic'] = True - - elif os.path.join(filedir, name) in pics: - args['pic'] = True - - elif filedir == 'gfx/tilesets': - args['tileset'] = True - - if args.get('pal_file'): - if os.path.exists(args['pal_file']): - args['palout'] = args['pal_file'] - else: - del args['pal_file'] - - if args.get('pic'): - if ext == '.png': - w, h = gfx.png.Reader(filepath).asRGBA8()[:2] - w = min(w/8, h/8) - args['pic_dimensions'] = w, w - elif ext == '.2bpp': - if pokemon_name and name == 'front' or name == 'front.animated': - w, h = get_pokemon_dimensions(filepath.replace(ext, '.dimensions')) or (7, 7) - args['pic_dimensions'] = w, w - elif pokemon_name and name == 'back': - args['pic_dimensions'] = 6, 6 - else: - args['pic_dimensions'] = 7, 7 - - if args.get('tileset'): - args['width'] = 128 - return args - - -def to_1bpp(filename, **kwargs): - name, ext = os.path.splitext(filename) - if ext == '.1bpp': pass - elif ext == '.2bpp': gfx.export_2bpp_to_1bpp(filename, **kwargs) - elif ext == '.png': gfx.export_png_to_1bpp(filename, **kwargs) - elif ext == '.lz': - decompress(filename, **kwargs) - to_1bpp(name, **kwargs) - -def to_2bpp(filename, **kwargs): - name, ext = os.path.splitext(filename) - if ext == '.1bpp': gfx.export_1bpp_to_2bpp(filename, **kwargs) - elif ext == '.2bpp': pass - elif ext == '.png': gfx.export_png_to_2bpp(filename, **kwargs) - elif ext == '.lz': - decompress(filename, **kwargs) - to_2bpp(name, **kwargs) - -def to_png(filename, **kwargs): - name, ext = os.path.splitext(filename) - if ext == '.1bpp': gfx.export_1bpp_to_png(filename, **kwargs) - elif ext == '.2bpp' and name.endswith('.animated'): - w, h = kwargs.get('pic_dimensions') or (7, 7) - new_path = get_animated_graphics(filename, w=w, h=h) - return to_png(new_path, **kwargs) - elif ext == '.2bpp': gfx.export_2bpp_to_png(filename, **kwargs) - elif ext == '.png': pass - elif ext == '.lz': - decompress(filename, **kwargs) - to_png(name, **kwargs) - -def compress(filename, **kwargs): - data = open(filename, 'rb').read() - lz_data = lz.Compressed(data).output - open(filename + '.lz', 'wb').write(bytearray(lz_data)) - -def decompress(filename, **kwargs): - lz_data = open(filename, 'rb').read() - data = lz.Decompressed(lz_data).output - name, ext = os.path.splitext(filename) - open(name, 'wb').write(bytearray(data)) - - -methods = { - '2bpp': to_2bpp, - '1bpp': to_1bpp, - 'png': to_png, - 'lz': compress, - 'unlz': decompress, -} - -def main(method_name, filenames=None): - if filenames is None: filenames = [] - for filename in filenames: - args = filepath_rules(filename) - method = methods.get(method_name) - if method: - method(filename, **args) - -def get_args(): - ap = argparse.ArgumentParser() - ap.add_argument('method_name') - ap.add_argument('filenames', nargs='*') - args = ap.parse_args() - return args - -if __name__ == '__main__': - main(**get_args().__dict__) diff --git a/tools/mapreader.py b/tools/mapreader.py index de2ec3423..42eaa76de 100644 --- a/tools/mapreader.py +++ b/tools/mapreader.py @@ -1,3 +1,4 @@ +#!/usr/bin/env python3 # -*- coding: utf-8 -*- # A library for parsing the pokecrystal.map file output by rgbds. diff --git a/tools/palfix.py b/tools/palfix.py index 8d53d35e7..2ecd3236d 100755 --- a/tools/palfix.py +++ b/tools/palfix.py @@ -1,4 +1,4 @@ -#!/usr/bin/env python +#!/usr/bin/env python3 # -*- coding: utf-8 -*- """ @@ -9,10 +9,9 @@ sprites) will become indexed, with a palette sorted {white, light color, dark color, black}. Grayscale images will become two-bit grayscale. """ -from __future__ import print_function - import sys -from pokemontools import png + +import png def rgb8_to_rgb5(c): r, g, b = c diff --git a/tools/png.py b/tools/png.py new file mode 100755 index 000000000..dd9746bf0 --- /dev/null +++ b/tools/png.py @@ -0,0 +1,2357 @@ +#!/usr/bin/env python3 +# -*- coding: utf-8 -*- + +# png.py - PNG encoder/decoder in pure Python +# +# Copyright (C) 2006 Johann C. Rocholl +# Portions Copyright (C) 2009 David Jones +# And probably portions Copyright (C) 2006 Nicko van Someren +# +# Original concept by Johann C. Rocholl. +# +# LICENCE (MIT) +# +# Permission is hereby granted, free of charge, to any person +# obtaining a copy of this software and associated documentation files +# (the "Software"), to deal in the Software without restriction, +# including without limitation the rights to use, copy, modify, merge, +# publish, distribute, sublicense, and/or sell copies of the Software, +# and to permit persons to whom the Software is furnished to do so, +# subject to the following conditions: +# +# The above copyright notice and this permission notice shall be +# included in all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. + +""" +The ``png`` module can read and write PNG files. + +Installation and Overview +------------------------- + +``pip install pypng`` + +For help, type ``import png; help(png)`` in your python interpreter. + +A good place to start is the :class:`Reader` and :class:`Writer` classes. + +Coverage of PNG formats is fairly complete; +all allowable bit depths (1/2/4/8/16/24/32/48/64 bits per pixel) and +colour combinations are supported: + +- greyscale (1/2/4/8/16 bit); +- RGB, RGBA, LA (greyscale with alpha) with 8/16 bits per channel; +- colour mapped images (1/2/4/8 bit). + +Interlaced images, +which support a progressive display when downloading, +are supported for both reading and writing. + +A number of optional chunks can be specified (when writing) +and understood (when reading): ``tRNS``, ``bKGD``, ``gAMA``. + +The ``sBIT`` chunk can be used to specify precision for +non-native bit depths. + +Requires Python 3.5 or higher. +Installation is trivial, +but see the ``README.txt`` file (with the source distribution) for details. + +Full use of all features will need some reading of the PNG specification +http://www.w3.org/TR/2003/REC-PNG-20031110/. + +The package also comes with command line utilities. + +- ``pripamtopng`` converts + `Netpbm `_ PAM/PNM files to PNG; +- ``pripngtopam`` converts PNG to file PAM/PNM. + +There are a few more for simple PNG manipulations. + +Spelling and Terminology +------------------------ + +Generally British English spelling is used in the documentation. +So that's "greyscale" and "colour". +This not only matches the author's native language, +it's also used by the PNG specification. + +Colour Models +------------- + +The major colour models supported by PNG (and hence by PyPNG) are: + +- greyscale; +- greyscale--alpha; +- RGB; +- RGB--alpha. + +Also referred to using the abbreviations: L, LA, RGB, RGBA. +Each letter codes a single channel: +*L* is for Luminance or Luma or Lightness (greyscale images); +*A* stands for Alpha, the opacity channel +(used for transparency effects, but higher values are more opaque, +so it makes sense to call it opacity); +*R*, *G*, *B* stand for Red, Green, Blue (colour image). + +Lists, arrays, sequences, and so on +----------------------------------- + +When getting pixel data out of this module (reading) and +presenting data to this module (writing) there are +a number of ways the data could be represented as a Python value. + +The preferred format is a sequence of *rows*, +which each row being a sequence of *values*. +In this format, the values are in pixel order, +with all the values from all the pixels in a row +being concatenated into a single sequence for that row. + +Consider an image that is 3 pixels wide by 2 pixels high, and each pixel +has RGB components: + +Sequence of rows:: + + list([R,G,B, R,G,B, R,G,B], + [R,G,B, R,G,B, R,G,B]) + +Each row appears as its own list, +but the pixels are flattened so that three values for one pixel +simply follow the three values for the previous pixel. + +This is the preferred because +it provides a good compromise between space and convenience. +PyPNG regards itself as at liberty to replace any sequence type with +any sufficiently compatible other sequence type; +in practice each row is an array (``bytearray`` or ``array.array``). + +To allow streaming the outer list is sometimes +an iterator rather than an explicit list. + +An alternative format is a single array holding all the values. + +Array of values:: + + [R,G,B, R,G,B, R,G,B, + R,G,B, R,G,B, R,G,B] + +The entire image is one single giant sequence of colour values. +Generally an array will be used (to save space), not a list. + +The top row comes first, +and within each row the pixels are ordered from left-to-right. +Within a pixel the values appear in the order R-G-B-A +(or L-A for greyscale--alpha). + +There is another format, which should only be used with caution. +It is mentioned because it is used internally, +is close to what lies inside a PNG file itself, +and has some support from the public API. +This format is called *packed*. +When packed, each row is a sequence of bytes (integers from 0 to 255), +just as it is before PNG scanline filtering is applied. +When the bit depth is 8 this is the same as a sequence of rows; +when the bit depth is less than 8 (1, 2 and 4), +several pixels are packed into each byte; +when the bit depth is 16 each pixel value is decomposed into 2 bytes +(and `packed` is a misnomer). +This format is used by the :meth:`Writer.write_packed` method. +It isn't usually a convenient format, +but may be just right if the source data for +the PNG image comes from something that uses a similar format +(for example, 1-bit BMPs, or another PNG file). +""" + +__version__ = "0.0.21" + +import collections +import io # For io.BytesIO +import itertools +import math +# http://www.python.org/doc/2.4.4/lib/module-operator.html +import operator +import re +import struct +import sys +# http://www.python.org/doc/2.4.4/lib/module-warnings.html +import warnings +import zlib + +from array import array + + +__all__ = ['Image', 'Reader', 'Writer', 'write_chunks', 'from_array'] + + +# The PNG signature. +# http://www.w3.org/TR/PNG/#5PNG-file-signature +signature = struct.pack('8B', 137, 80, 78, 71, 13, 10, 26, 10) + +# The xstart, ystart, xstep, ystep for the Adam7 interlace passes. +adam7 = ((0, 0, 8, 8), + (4, 0, 8, 8), + (0, 4, 4, 8), + (2, 0, 4, 4), + (0, 2, 2, 4), + (1, 0, 2, 2), + (0, 1, 1, 2)) + + +def adam7_generate(width, height): + """ + Generate the coordinates for the reduced scanlines + of an Adam7 interlaced image + of size `width` by `height` pixels. + + Yields a generator for each pass, + and each pass generator yields a series of (x, y, xstep) triples, + each one identifying a reduced scanline consisting of + pixels starting at (x, y) and taking every xstep pixel to the right. + """ + + for xstart, ystart, xstep, ystep in adam7: + if xstart >= width: + continue + yield ((xstart, y, xstep) for y in range(ystart, height, ystep)) + + +# Models the 'pHYs' chunk (used by the Reader) +Resolution = collections.namedtuple('_Resolution', 'x y unit_is_meter') + + +def group(s, n): + return list(zip(* [iter(s)] * n)) + + +def isarray(x): + return isinstance(x, array) + + +def check_palette(palette): + """ + Check a palette argument (to the :class:`Writer` class) for validity. + Returns the palette as a list if okay; + raises an exception otherwise. + """ + + # None is the default and is allowed. + if palette is None: + return None + + p = list(palette) + if not (0 < len(p) <= 256): + raise ProtocolError( + "a palette must have between 1 and 256 entries," + " see https://www.w3.org/TR/PNG/#11PLTE") + seen_triple = False + for i, t in enumerate(p): + if len(t) not in (3, 4): + raise ProtocolError( + "palette entry %d: entries must be 3- or 4-tuples." % i) + if len(t) == 3: + seen_triple = True + if seen_triple and len(t) == 4: + raise ProtocolError( + "palette entry %d: all 4-tuples must precede all 3-tuples" % i) + for x in t: + if int(x) != x or not(0 <= x <= 255): + raise ProtocolError( + "palette entry %d: " + "values must be integer: 0 <= x <= 255" % i) + return p + + +def check_sizes(size, width, height): + """ + Check that these arguments, if supplied, are consistent. + Return a (width, height) pair. + """ + + if not size: + return width, height + + if len(size) != 2: + raise ProtocolError( + "size argument should be a pair (width, height)") + if width is not None and width != size[0]: + raise ProtocolError( + "size[0] (%r) and width (%r) should match when both are used." + % (size[0], width)) + if height is not None and height != size[1]: + raise ProtocolError( + "size[1] (%r) and height (%r) should match when both are used." + % (size[1], height)) + return size + + +def check_color(c, greyscale, which): + """ + Checks that a colour argument for transparent or background options + is the right form. + Returns the colour + (which, if it's a bare integer, is "corrected" to a 1-tuple). + """ + + if c is None: + return c + if greyscale: + try: + len(c) + except TypeError: + c = (c,) + if len(c) != 1: + raise ProtocolError("%s for greyscale must be 1-tuple" % which) + if not is_natural(c[0]): + raise ProtocolError( + "%s colour for greyscale must be integer" % which) + else: + if not (len(c) == 3 and + is_natural(c[0]) and + is_natural(c[1]) and + is_natural(c[2])): + raise ProtocolError( + "%s colour must be a triple of integers" % which) + return c + + +class Error(Exception): + def __str__(self): + return self.__class__.__name__ + ': ' + ' '.join(self.args) + + +class FormatError(Error): + """ + Problem with input file format. + In other words, PNG file does not conform to + the specification in some way and is invalid. + """ + + +class ProtocolError(Error): + """ + Problem with the way the programming interface has been used, + or the data presented to it. + """ + + +class ChunkError(FormatError): + pass + + +class Default: + """The default for the greyscale parameter.""" + + +class Writer: + """ + PNG encoder in pure Python. + """ + + def __init__(self, width=None, height=None, + size=None, + greyscale=Default, + alpha=False, + bitdepth=8, + palette=None, + transparent=None, + background=None, + gamma=None, + compression=None, + interlace=False, + planes=None, + colormap=None, + maxval=None, + chunk_limit=2**20, + x_pixels_per_unit=None, + y_pixels_per_unit=None, + unit_is_meter=False): + """ + Create a PNG encoder object. + + Arguments: + + width, height + Image size in pixels, as two separate arguments. + size + Image size (w,h) in pixels, as single argument. + greyscale + Pixels are greyscale, not RGB. + alpha + Input data has alpha channel (RGBA or LA). + bitdepth + Bit depth: from 1 to 16 (for each channel). + palette + Create a palette for a colour mapped image (colour type 3). + transparent + Specify a transparent colour (create a ``tRNS`` chunk). + background + Specify a default background colour (create a ``bKGD`` chunk). + gamma + Specify a gamma value (create a ``gAMA`` chunk). + compression + zlib compression level: 0 (none) to 9 (more compressed); + default: -1 or None. + interlace + Create an interlaced image. + chunk_limit + Write multiple ``IDAT`` chunks to save memory. + x_pixels_per_unit + Number of pixels a unit along the x axis (write a + `pHYs` chunk). + y_pixels_per_unit + Number of pixels a unit along the y axis (write a + `pHYs` chunk). Along with `x_pixel_unit`, this gives + the pixel size ratio. + unit_is_meter + `True` to indicate that the unit (for the `pHYs` + chunk) is metre. + + The image size (in pixels) can be specified either by using the + `width` and `height` arguments, or with the single `size` + argument. + If `size` is used it should be a pair (*width*, *height*). + + The `greyscale` argument indicates whether input pixels + are greyscale (when true), or colour (when false). + The default is true unless `palette=` is used. + + The `alpha` argument (a boolean) specifies + whether input pixels have an alpha channel (or not). + + `bitdepth` specifies the bit depth of the source pixel values. + Each channel may have a different bit depth. + Each source pixel must have values that are + an integer between 0 and ``2**bitdepth-1``, where + `bitdepth` is the bit depth for the corresponding channel. + For example, 8-bit images have values between 0 and 255. + PNG only stores images with bit depths of + 1,2,4,8, or 16 (the same for all channels). + When `bitdepth` is not one of these values or where + channels have different bit depths, + the next highest valid bit depth is selected, + and an ``sBIT`` (significant bits) chunk is generated + that specifies the original precision of the source image. + In this case the supplied pixel values will be rescaled to + fit the range of the selected bit depth. + + The PNG file format supports many bit depth / colour model + combinations, but not all. + The details are somewhat arcane + (refer to the PNG specification for full details). + Briefly: + Bit depths < 8 (1,2,4) are only allowed with greyscale and + colour mapped images; + colour mapped images cannot have bit depth 16. + + For colour mapped images + (in other words, when the `palette` argument is specified) + the `bitdepth` argument must match one of + the valid PNG bit depths: 1, 2, 4, or 8. + (It is valid to have a PNG image with a palette and + an ``sBIT`` chunk, but the meaning is slightly different; + it would be awkward to use the `bitdepth` argument for this.) + + The `palette` option, when specified, + causes a colour mapped image to be created: + the PNG colour type is set to 3; + `greyscale` must not be true; `alpha` must not be true; + `transparent` must not be set. + The bit depth must be 1,2,4, or 8. + When a colour mapped image is created, + the pixel values are palette indexes and + the `bitdepth` argument specifies the size of these indexes + (not the size of the colour values in the palette). + + The palette argument value should be a sequence of 3- or + 4-tuples. + 3-tuples specify RGB palette entries; + 4-tuples specify RGBA palette entries. + All the 4-tuples (if present) must come before all the 3-tuples. + A ``PLTE`` chunk is created; + if there are 4-tuples then a ``tRNS`` chunk is created as well. + The ``PLTE`` chunk will contain all the RGB triples in the same + sequence; + the ``tRNS`` chunk will contain the alpha channel for + all the 4-tuples, in the same sequence. + Palette entries are always 8-bit. + + If specified, the `transparent` and `background` parameters must be + a tuple with one element for each channel in the image. + Either a 3-tuple of integer (RGB) values for a colour image, or + a 1-tuple of a single integer for a greyscale image. + + If specified, the `gamma` parameter must be a positive number + (generally, a `float`). + A ``gAMA`` chunk will be created. + Note that this will not change the values of the pixels as + they appear in the PNG file, + they are assumed to have already + been converted appropriately for the gamma specified. + + The `compression` argument specifies the compression level to + be used by the ``zlib`` module. + Values from 1 to 9 (highest) specify compression. + 0 means no compression. + -1 and ``None`` both mean that the ``zlib`` module uses + the default level of compression (which is generally acceptable). + + If `interlace` is true then an interlaced image is created + (using PNG's so far only interlace method, *Adam7*). + This does not affect how the pixels should be passed in, + rather it changes how they are arranged into the PNG file. + On slow connexions interlaced images can be + partially decoded by the browser to give + a rough view of the image that is + successively refined as more image data appears. + + .. note :: + + Enabling the `interlace` option requires the entire image + to be processed in working memory. + + `chunk_limit` is used to limit the amount of memory used whilst + compressing the image. + In order to avoid using large amounts of memory, + multiple ``IDAT`` chunks may be created. + """ + + # At the moment the `planes` argument is ignored; + # its purpose is to act as a dummy so that + # ``Writer(x, y, **info)`` works, where `info` is a dictionary + # returned by Reader.read and friends. + # Ditto for `colormap`. + + width, height = check_sizes(size, width, height) + del size + + if not is_natural(width) or not is_natural(height): + raise ProtocolError("width and height must be integers") + if width <= 0 or height <= 0: + raise ProtocolError("width and height must be greater than zero") + # http://www.w3.org/TR/PNG/#7Integers-and-byte-order + if width > 2 ** 31 - 1 or height > 2 ** 31 - 1: + raise ProtocolError("width and height cannot exceed 2**31-1") + + if alpha and transparent is not None: + raise ProtocolError( + "transparent colour not allowed with alpha channel") + + # bitdepth is either single integer, or tuple of integers. + # Convert to tuple. + try: + len(bitdepth) + except TypeError: + bitdepth = (bitdepth, ) + for b in bitdepth: + valid = is_natural(b) and 1 <= b <= 16 + if not valid: + raise ProtocolError( + "each bitdepth %r must be a positive integer <= 16" % + (bitdepth,)) + + # Calculate channels, and + # expand bitdepth to be one element per channel. + palette = check_palette(palette) + alpha = bool(alpha) + colormap = bool(palette) + if greyscale is Default and palette: + greyscale = False + greyscale = bool(greyscale) + if colormap: + color_planes = 1 + planes = 1 + else: + color_planes = (3, 1)[greyscale] + planes = color_planes + alpha + if len(bitdepth) == 1: + bitdepth *= planes + + bitdepth, self.rescale = check_bitdepth_rescale( + palette, + bitdepth, + transparent, alpha, greyscale) + + # These are assertions, because above logic should have + # corrected or raised all problematic cases. + if bitdepth < 8: + assert greyscale or palette + assert not alpha + if bitdepth > 8: + assert not palette + + transparent = check_color(transparent, greyscale, 'transparent') + background = check_color(background, greyscale, 'background') + + # It's important that the true boolean values + # (greyscale, alpha, colormap, interlace) are converted + # to bool because Iverson's convention is relied upon later on. + self.width = width + self.height = height + self.transparent = transparent + self.background = background + self.gamma = gamma + self.greyscale = greyscale + self.alpha = alpha + self.colormap = colormap + self.bitdepth = int(bitdepth) + self.compression = compression + self.chunk_limit = chunk_limit + self.interlace = bool(interlace) + self.palette = palette + self.x_pixels_per_unit = x_pixels_per_unit + self.y_pixels_per_unit = y_pixels_per_unit + self.unit_is_meter = bool(unit_is_meter) + + self.color_type = (4 * self.alpha + + 2 * (not greyscale) + + 1 * self.colormap) + assert self.color_type in (0, 2, 3, 4, 6) + + self.color_planes = color_planes + self.planes = planes + # :todo: fix for bitdepth < 8 + self.psize = (self.bitdepth / 8) * self.planes + + def write(self, outfile, rows): + """ + Write a PNG image to the output file. + `rows` should be an iterable that yields each row + (each row is a sequence of values). + The rows should be the rows of the original image, + so there should be ``self.height`` rows of + ``self.width * self.planes`` values. + If `interlace` is specified (when creating the instance), + then an interlaced PNG file will be written. + Supply the rows in the normal image order; + the interlacing is carried out internally. + + .. note :: + + Interlacing requires the entire image to be in working memory. + """ + + # Values per row + vpr = self.width * self.planes + + def check_rows(rows): + """ + Yield each row in rows, + but check each row first (for correct width). + """ + for i, row in enumerate(rows): + try: + wrong_length = len(row) != vpr + except TypeError: + # When using an itertools.ichain object or + # other generator not supporting __len__, + # we set this to False to skip the check. + wrong_length = False + if wrong_length: + # Note: row numbers start at 0. + raise ProtocolError( + "Expected %d values but got %d values, in row %d" % + (vpr, len(row), i)) + yield row + + if self.interlace: + fmt = 'BH'[self.bitdepth > 8] + a = array(fmt, itertools.chain(*check_rows(rows))) + return self.write_array(outfile, a) + + nrows = self.write_passes(outfile, check_rows(rows)) + if nrows != self.height: + raise ProtocolError( + "rows supplied (%d) does not match height (%d)" % + (nrows, self.height)) + return nrows + + def write_passes(self, outfile, rows): + """ + Write a PNG image to the output file. + + Most users are expected to find the :meth:`write` or + :meth:`write_array` method more convenient. + + The rows should be given to this method in the order that + they appear in the output file. + For straightlaced images, this is the usual top to bottom ordering. + For interlaced images the rows should have been interlaced before + passing them to this function. + + `rows` should be an iterable that yields each row + (each row being a sequence of values). + """ + + # Ensure rows are scaled (to 4-/8-/16-bit), + # and packed into bytes. + + if self.rescale: + rows = rescale_rows(rows, self.rescale) + + if self.bitdepth < 8: + rows = pack_rows(rows, self.bitdepth) + elif self.bitdepth == 16: + rows = unpack_rows(rows) + + return self.write_packed(outfile, rows) + + def write_packed(self, outfile, rows): + """ + Write PNG file to `outfile`. + `rows` should be an iterator that yields each packed row; + a packed row being a sequence of packed bytes. + + The rows have a filter byte prefixed and + are then compressed into one or more IDAT chunks. + They are not processed any further, + so if bitdepth is other than 1, 2, 4, 8, 16, + the pixel values should have been scaled + before passing them to this method. + + This method does work for interlaced images but it is best avoided. + For interlaced images, the rows should be + presented in the order that they appear in the file. + """ + + self.write_preamble(outfile) + + # http://www.w3.org/TR/PNG/#11IDAT + if self.compression is not None: + compressor = zlib.compressobj(self.compression) + else: + compressor = zlib.compressobj() + + # data accumulates bytes to be compressed for the IDAT chunk; + # it's compressed when sufficiently large. + data = bytearray() + + # raise i scope out of the for loop. set to -1, because the for loop + # sets i to 0 on the first pass + i = -1 + for i, row in enumerate(rows): + # Add "None" filter type. + # Currently, it's essential that this filter type be used + # for every scanline as + # we do not mark the first row of a reduced pass image; + # that means we could accidentally compute + # the wrong filtered scanline if we used + # "up", "average", or "paeth" on such a line. + data.append(0) + data.extend(row) + if len(data) > self.chunk_limit: + compressed = compressor.compress(data) + if len(compressed): + write_chunk(outfile, b'IDAT', compressed) + data = bytearray() + + compressed = compressor.compress(bytes(data)) + flushed = compressor.flush() + if len(compressed) or len(flushed): + write_chunk(outfile, b'IDAT', compressed + flushed) + # http://www.w3.org/TR/PNG/#11IEND + write_chunk(outfile, b'IEND') + return i + 1 + + def write_preamble(self, outfile): + # http://www.w3.org/TR/PNG/#5PNG-file-signature + outfile.write(signature) + + # http://www.w3.org/TR/PNG/#11IHDR + write_chunk(outfile, b'IHDR', + struct.pack("!2I5B", self.width, self.height, + self.bitdepth, self.color_type, + 0, 0, self.interlace)) + + # See :chunk:order + # http://www.w3.org/TR/PNG/#11gAMA + if self.gamma is not None: + write_chunk(outfile, b'gAMA', + struct.pack("!L", int(round(self.gamma * 1e5)))) + + # See :chunk:order + # http://www.w3.org/TR/PNG/#11sBIT + if self.rescale: + write_chunk( + outfile, b'sBIT', + struct.pack('%dB' % self.planes, + * [s[0] for s in self.rescale])) + + # :chunk:order: Without a palette (PLTE chunk), + # ordering is relatively relaxed. + # With one, gAMA chunk must precede PLTE chunk + # which must precede tRNS and bKGD. + # See http://www.w3.org/TR/PNG/#5ChunkOrdering + if self.palette: + p, t = make_palette_chunks(self.palette) + write_chunk(outfile, b'PLTE', p) + if t: + # tRNS chunk is optional; + # Only needed if palette entries have alpha. + write_chunk(outfile, b'tRNS', t) + + # http://www.w3.org/TR/PNG/#11tRNS + if self.transparent is not None: + if self.greyscale: + fmt = "!1H" + else: + fmt = "!3H" + write_chunk(outfile, b'tRNS', + struct.pack(fmt, *self.transparent)) + + # http://www.w3.org/TR/PNG/#11bKGD + if self.background is not None: + if self.greyscale: + fmt = "!1H" + else: + fmt = "!3H" + write_chunk(outfile, b'bKGD', + struct.pack(fmt, *self.background)) + + # http://www.w3.org/TR/PNG/#11pHYs + if (self.x_pixels_per_unit is not None and + self.y_pixels_per_unit is not None): + tup = (self.x_pixels_per_unit, + self.y_pixels_per_unit, + int(self.unit_is_meter)) + write_chunk(outfile, b'pHYs', struct.pack("!LLB", *tup)) + + def write_array(self, outfile, pixels): + """ + Write an array that holds all the image values + as a PNG file on the output file. + See also :meth:`write` method. + """ + + if self.interlace: + if type(pixels) != array: + # Coerce to array type + fmt = 'BH'[self.bitdepth > 8] + pixels = array(fmt, pixels) + return self.write_passes( + outfile, + self.array_scanlines_interlace(pixels) + ) + else: + return self.write_passes( + outfile, + self.array_scanlines(pixels) + ) + + def array_scanlines(self, pixels): + """ + Generates rows (each a sequence of values) from + a single array of values. + """ + + # Values per row + vpr = self.width * self.planes + stop = 0 + for y in range(self.height): + start = stop + stop = start + vpr + yield pixels[start:stop] + + def array_scanlines_interlace(self, pixels): + """ + Generator for interlaced scanlines from an array. + `pixels` is the full source image as a single array of values. + The generator yields each scanline of the reduced passes in turn, + each scanline being a sequence of values. + """ + + # http://www.w3.org/TR/PNG/#8InterlaceMethods + # Array type. + fmt = 'BH'[self.bitdepth > 8] + # Value per row + vpr = self.width * self.planes + + # Each iteration generates a scanline starting at (x, y) + # and consisting of every xstep pixels. + for lines in adam7_generate(self.width, self.height): + for x, y, xstep in lines: + # Pixels per row (of reduced image) + ppr = int(math.ceil((self.width - x) / float(xstep))) + # Values per row (of reduced image) + reduced_row_len = ppr * self.planes + if xstep == 1: + # Easy case: line is a simple slice. + offset = y * vpr + yield pixels[offset: offset + vpr] + continue + # We have to step by xstep, + # which we can do one plane at a time + # using the step in Python slices. + row = array(fmt) + # There's no easier way to set the length of an array + row.extend(pixels[0:reduced_row_len]) + offset = y * vpr + x * self.planes + end_offset = (y + 1) * vpr + skip = self.planes * xstep + for i in range(self.planes): + row[i::self.planes] = \ + pixels[offset + i: end_offset: skip] + yield row + + +def write_chunk(outfile, tag, data=b''): + """ + Write a PNG chunk to the output file, including length and + checksum. + """ + + data = bytes(data) + # http://www.w3.org/TR/PNG/#5Chunk-layout + outfile.write(struct.pack("!I", len(data))) + outfile.write(tag) + outfile.write(data) + checksum = zlib.crc32(tag) + checksum = zlib.crc32(data, checksum) + checksum &= 2 ** 32 - 1 + outfile.write(struct.pack("!I", checksum)) + + +def write_chunks(out, chunks): + """Create a PNG file by writing out the chunks.""" + + out.write(signature) + for chunk in chunks: + write_chunk(out, *chunk) + + +def rescale_rows(rows, rescale): + """ + Take each row in rows (an iterator) and yield + a fresh row with the pixels scaled according to + the rescale parameters in the list `rescale`. + Each element of `rescale` is a tuple of + (source_bitdepth, target_bitdepth), + with one element per channel. + """ + + # One factor for each channel + fs = [float(2 ** s[1] - 1)/float(2 ** s[0] - 1) + for s in rescale] + + # Assume all target_bitdepths are the same + target_bitdepths = set(s[1] for s in rescale) + assert len(target_bitdepths) == 1 + (target_bitdepth, ) = target_bitdepths + typecode = 'BH'[target_bitdepth > 8] + + # Number of channels + n_chans = len(rescale) + + for row in rows: + rescaled_row = array(typecode, iter(row)) + for i in range(n_chans): + channel = array( + typecode, + (int(round(fs[i] * x)) for x in row[i::n_chans])) + rescaled_row[i::n_chans] = channel + yield rescaled_row + + +def pack_rows(rows, bitdepth): + """Yield packed rows that are a byte array. + Each byte is packed with the values from several pixels. + """ + + assert bitdepth < 8 + assert 8 % bitdepth == 0 + + # samples per byte + spb = int(8 / bitdepth) + + def make_byte(block): + """Take a block of (2, 4, or 8) values, + and pack them into a single byte. + """ + + res = 0 + for v in block: + res = (res << bitdepth) + v + return res + + for row in rows: + a = bytearray(row) + # Adding padding bytes so we can group into a whole + # number of spb-tuples. + n = float(len(a)) + extra = math.ceil(n / spb) * spb - n + a.extend([0] * int(extra)) + # Pack into bytes. + # Each block is the samples for one byte. + blocks = group(a, spb) + yield bytearray(make_byte(block) for block in blocks) + + +def unpack_rows(rows): + """Unpack each row from being 16-bits per value, + to being a sequence of bytes. + """ + for row in rows: + fmt = '!%dH' % len(row) + yield bytearray(struct.pack(fmt, *row)) + + +def make_palette_chunks(palette): + """ + Create the byte sequences for a ``PLTE`` and + if necessary a ``tRNS`` chunk. + Returned as a pair (*p*, *t*). + *t* will be ``None`` if no ``tRNS`` chunk is necessary. + """ + + p = bytearray() + t = bytearray() + + for x in palette: + p.extend(x[0:3]) + if len(x) > 3: + t.append(x[3]) + if t: + return p, t + return p, None + + +def check_bitdepth_rescale( + palette, bitdepth, transparent, alpha, greyscale): + """ + Returns (bitdepth, rescale) pair. + """ + + if palette: + if len(bitdepth) != 1: + raise ProtocolError( + "with palette, only a single bitdepth may be used") + (bitdepth, ) = bitdepth + if bitdepth not in (1, 2, 4, 8): + raise ProtocolError( + "with palette, bitdepth must be 1, 2, 4, or 8") + if transparent is not None: + raise ProtocolError("transparent and palette not compatible") + if alpha: + raise ProtocolError("alpha and palette not compatible") + if greyscale: + raise ProtocolError("greyscale and palette not compatible") + return bitdepth, None + + # No palette, check for sBIT chunk generation. + + if greyscale and not alpha: + # Single channel, L. + (bitdepth,) = bitdepth + if bitdepth in (1, 2, 4, 8, 16): + return bitdepth, None + if bitdepth > 8: + targetbitdepth = 16 + elif bitdepth == 3: + targetbitdepth = 4 + else: + assert bitdepth in (5, 6, 7) + targetbitdepth = 8 + return targetbitdepth, [(bitdepth, targetbitdepth)] + + assert alpha or not greyscale + + depth_set = tuple(set(bitdepth)) + if depth_set in [(8,), (16,)]: + # No sBIT required. + (bitdepth, ) = depth_set + return bitdepth, None + + targetbitdepth = (8, 16)[max(bitdepth) > 8] + return targetbitdepth, [(b, targetbitdepth) for b in bitdepth] + + +# Regex for decoding mode string +RegexModeDecode = re.compile("(LA?|RGBA?);?([0-9]*)", flags=re.IGNORECASE) + + +def from_array(a, mode=None, info={}): + """ + Create a PNG :class:`Image` object from a 2-dimensional array. + One application of this function is easy PIL-style saving: + ``png.from_array(pixels, 'L').save('foo.png')``. + + Unless they are specified using the *info* parameter, + the PNG's height and width are taken from the array size. + The first axis is the height; the second axis is the + ravelled width and channel index. + The array is treated is a sequence of rows, + each row being a sequence of values (``width*channels`` in number). + So an RGB image that is 16 pixels high and 8 wide will + occupy a 2-dimensional array that is 16x24 + (each row will be 8*3 = 24 sample values). + + *mode* is a string that specifies the image colour format in a + PIL-style mode. It can be: + + ``'L'`` + greyscale (1 channel) + ``'LA'`` + greyscale with alpha (2 channel) + ``'RGB'`` + colour image (3 channel) + ``'RGBA'`` + colour image with alpha (4 channel) + + The mode string can also specify the bit depth + (overriding how this function normally derives the bit depth, + see below). + Appending ``';16'`` to the mode will cause the PNG to be + 16 bits per channel; + any decimal from 1 to 16 can be used to specify the bit depth. + + When a 2-dimensional array is used *mode* determines how many + channels the image has, and so allows the width to be derived from + the second array dimension. + + The array is expected to be a ``numpy`` array, + but it can be any suitable Python sequence. + For example, a list of lists can be used: + ``png.from_array([[0, 255, 0], [255, 0, 255]], 'L')``. + The exact rules are: ``len(a)`` gives the first dimension, height; + ``len(a[0])`` gives the second dimension. + It's slightly more complicated than that because + an iterator of rows can be used, and it all still works. + Using an iterator allows data to be streamed efficiently. + + The bit depth of the PNG is normally taken from + the array element's datatype + (but if *mode* specifies a bitdepth then that is used instead). + The array element's datatype is determined in a way which + is supposed to work both for ``numpy`` arrays and for Python + ``array.array`` objects. + A 1 byte datatype will give a bit depth of 8, + a 2 byte datatype will give a bit depth of 16. + If the datatype does not have an implicit size, + like the above example where it is a plain Python list of lists, + then a default of 8 is used. + + The *info* parameter is a dictionary that can + be used to specify metadata (in the same style as + the arguments to the :class:`png.Writer` class). + For this function the keys that are useful are: + + height + overrides the height derived from the array dimensions and + allows *a* to be an iterable. + width + overrides the width derived from the array dimensions. + bitdepth + overrides the bit depth derived from the element datatype + (but must match *mode* if that also specifies a bit depth). + + Generally anything specified in the *info* dictionary will + override any implicit choices that this function would otherwise make, + but must match any explicit ones. + For example, if the *info* dictionary has a ``greyscale`` key then + this must be true when mode is ``'L'`` or ``'LA'`` and + false when mode is ``'RGB'`` or ``'RGBA'``. + """ + + # We abuse the *info* parameter by modifying it. Take a copy here. + # (Also typechecks *info* to some extent). + info = dict(info) + + # Syntax check mode string. + match = RegexModeDecode.match(mode) + if not match: + raise Error("mode string should be 'RGB' or 'L;16' or similar.") + + mode, bitdepth = match.groups() + if bitdepth: + bitdepth = int(bitdepth) + + # Colour format. + if 'greyscale' in info: + if bool(info['greyscale']) != ('L' in mode): + raise ProtocolError("info['greyscale'] should match mode.") + info['greyscale'] = 'L' in mode + + alpha = 'A' in mode + if 'alpha' in info: + if bool(info['alpha']) != alpha: + raise ProtocolError("info['alpha'] should match mode.") + info['alpha'] = alpha + + # Get bitdepth from *mode* if possible. + if bitdepth: + if info.get("bitdepth") and bitdepth != info['bitdepth']: + raise ProtocolError( + "bitdepth (%d) should match bitdepth of info (%d)." % + (bitdepth, info['bitdepth'])) + info['bitdepth'] = bitdepth + + # Fill in and/or check entries in *info*. + # Dimensions. + width, height = check_sizes( + info.get("size"), + info.get("width"), + info.get("height")) + if width: + info["width"] = width + if height: + info["height"] = height + + if "height" not in info: + try: + info['height'] = len(a) + except TypeError: + raise ProtocolError( + "len(a) does not work, supply info['height'] instead.") + + planes = len(mode) + if 'planes' in info: + if info['planes'] != planes: + raise Error("info['planes'] should match mode.") + + # In order to work out whether we the array is 2D or 3D we need its + # first row, which requires that we take a copy of its iterator. + # We may also need the first row to derive width and bitdepth. + a, t = itertools.tee(a) + row = next(t) + del t + + testelement = row + if 'width' not in info: + width = len(row) // planes + info['width'] = width + + if 'bitdepth' not in info: + try: + dtype = testelement.dtype + # goto the "else:" clause. Sorry. + except AttributeError: + try: + # Try a Python array.array. + bitdepth = 8 * testelement.itemsize + except AttributeError: + # We can't determine it from the array element's datatype, + # use a default of 8. + bitdepth = 8 + else: + # If we got here without exception, + # we now assume that the array is a numpy array. + if dtype.kind == 'b': + bitdepth = 1 + else: + bitdepth = 8 * dtype.itemsize + info['bitdepth'] = bitdepth + + for thing in ["width", "height", "bitdepth", "greyscale", "alpha"]: + assert thing in info + + return Image(a, info) + + +# So that refugee's from PIL feel more at home. Not documented. +fromarray = from_array + + +class Image: + """A PNG image. You can create an :class:`Image` object from + an array of pixels by calling :meth:`png.from_array`. It can be + saved to disk with the :meth:`save` method. + """ + + def __init__(self, rows, info): + """ + .. note :: + + The constructor is not public. Please do not call it. + """ + + self.rows = rows + self.info = info + + def save(self, file): + """Save the image to the named *file*. + + See `.write()` if you already have an open file object. + + In general, you can only call this method once; + after it has been called the first time the PNG image is written, + the source data will have been streamed, and + cannot be streamed again. + """ + + w = Writer(**self.info) + + with open(file, 'wb') as fd: + w.write(fd, self.rows) + + def write(self, file): + """Write the image to the open file object. + + See `.save()` if you have a filename. + + In general, you can only call this method once; + after it has been called the first time the PNG image is written, + the source data will have been streamed, and + cannot be streamed again. + """ + + w = Writer(**self.info) + w.write(file, self.rows) + + +class Reader: + """ + Pure Python PNG decoder in pure Python. + """ + + def __init__(self, _guess=None, filename=None, file=None, bytes=None): + """ + The constructor expects exactly one keyword argument. + If you supply a positional argument instead, + it will guess the input type. + Choose from the following keyword arguments: + + filename + Name of input file (a PNG file). + file + A file-like object (object with a read() method). + bytes + ``bytes`` or ``bytearray`` with PNG data. + + """ + keywords_supplied = ( + (_guess is not None) + + (filename is not None) + + (file is not None) + + (bytes is not None)) + if keywords_supplied != 1: + raise TypeError("Reader() takes exactly 1 argument") + + # Will be the first 8 bytes, later on. See validate_signature. + self.signature = None + self.transparent = None + # A pair of (len,type) if a chunk has been read but its data and + # checksum have not (in other words the file position is just + # past the 4 bytes that specify the chunk type). + # See preamble method for how this is used. + self.atchunk = None + + if _guess is not None: + if isarray(_guess): + bytes = _guess + elif isinstance(_guess, str): + filename = _guess + elif hasattr(_guess, 'read'): + file = _guess + + if bytes is not None: + self.file = io.BytesIO(bytes) + elif filename is not None: + self.file = open(filename, "rb") + elif file is not None: + self.file = file + else: + raise ProtocolError("expecting filename, file or bytes array") + + def chunk(self, lenient=False): + """ + Read the next PNG chunk from the input file; + returns a (*type*, *data*) tuple. + *type* is the chunk's type as a byte string + (all PNG chunk types are 4 bytes long). + *data* is the chunk's data content, as a byte string. + + If the optional `lenient` argument evaluates to `True`, + checksum failures will raise warnings rather than exceptions. + """ + + self.validate_signature() + + # http://www.w3.org/TR/PNG/#5Chunk-layout + if not self.atchunk: + self.atchunk = self._chunk_len_type() + if not self.atchunk: + raise ChunkError("No more chunks.") + length, type = self.atchunk + self.atchunk = None + + data = self.file.read(length) + if len(data) != length: + raise ChunkError( + 'Chunk %s too short for required %i octets.' + % (type, length)) + checksum = self.file.read(4) + if len(checksum) != 4: + raise ChunkError('Chunk %s too short for checksum.' % type) + verify = zlib.crc32(type) + verify = zlib.crc32(data, verify) + verify = struct.pack('!I', verify) + if checksum != verify: + (a, ) = struct.unpack('!I', checksum) + (b, ) = struct.unpack('!I', verify) + message = ("Checksum error in %s chunk: 0x%08X != 0x%08X." + % (type.decode('ascii'), a, b)) + if lenient: + warnings.warn(message, RuntimeWarning) + else: + raise ChunkError(message) + return type, data + + def chunks(self): + """Return an iterator that will yield each chunk as a + (*chunktype*, *content*) pair. + """ + + while True: + t, v = self.chunk() + yield t, v + if t == b'IEND': + break + + def undo_filter(self, filter_type, scanline, previous): + """ + Undo the filter for a scanline. + `scanline` is a sequence of bytes that + does not include the initial filter type byte. + `previous` is decoded previous scanline + (for straightlaced images this is the previous pixel row, + but for interlaced images, it is + the previous scanline in the reduced image, + which in general is not the previous pixel row in the final image). + When there is no previous scanline + (the first row of a straightlaced image, + or the first row in one of the passes in an interlaced image), + then this argument should be ``None``. + + The scanline will have the effects of filtering removed; + the result will be returned as a fresh sequence of bytes. + """ + + # :todo: Would it be better to update scanline in place? + result = scanline + + if filter_type == 0: + return result + + if filter_type not in (1, 2, 3, 4): + raise FormatError( + 'Invalid PNG Filter Type. ' + 'See http://www.w3.org/TR/2003/REC-PNG-20031110/#9Filters .') + + # Filter unit. The stride from one pixel to the corresponding + # byte from the previous pixel. Normally this is the pixel + # size in bytes, but when this is smaller than 1, the previous + # byte is used instead. + fu = max(1, self.psize) + + # For the first line of a pass, synthesize a dummy previous + # line. An alternative approach would be to observe that on the + # first line 'up' is the same as 'null', 'paeth' is the same + # as 'sub', with only 'average' requiring any special case. + if not previous: + previous = bytearray([0] * len(scanline)) + + # Call appropriate filter algorithm. Note that 0 has already + # been dealt with. + fn = (None, + undo_filter_sub, + undo_filter_up, + undo_filter_average, + undo_filter_paeth)[filter_type] + fn(fu, scanline, previous, result) + return result + + def _deinterlace(self, raw): + """ + Read raw pixel data, undo filters, deinterlace, and flatten. + Return a single array of values. + """ + + # Values per row (of the target image) + vpr = self.width * self.planes + + # Values per image + vpi = vpr * self.height + # Interleaving writes to the output array randomly + # (well, not quite), so the entire output array must be in memory. + # Make a result array, and make it big enough. + if self.bitdepth > 8: + a = array('H', [0] * vpi) + else: + a = bytearray([0] * vpi) + source_offset = 0 + + for lines in adam7_generate(self.width, self.height): + # The previous (reconstructed) scanline. + # `None` at the beginning of a pass + # to indicate that there is no previous line. + recon = None + for x, y, xstep in lines: + # Pixels per row (reduced pass image) + ppr = int(math.ceil((self.width - x) / float(xstep))) + # Row size in bytes for this pass. + row_size = int(math.ceil(self.psize * ppr)) + + filter_type = raw[source_offset] + source_offset += 1 + scanline = raw[source_offset: source_offset + row_size] + source_offset += row_size + recon = self.undo_filter(filter_type, scanline, recon) + # Convert so that there is one element per pixel value + flat = self._bytes_to_values(recon, width=ppr) + if xstep == 1: + assert x == 0 + offset = y * vpr + a[offset: offset + vpr] = flat + else: + offset = y * vpr + x * self.planes + end_offset = (y + 1) * vpr + skip = self.planes * xstep + for i in range(self.planes): + a[offset + i: end_offset: skip] = \ + flat[i:: self.planes] + + return a + + def _iter_bytes_to_values(self, byte_rows): + """ + Iterator that yields each scanline; + each scanline being a sequence of values. + `byte_rows` should be an iterator that yields + the bytes of each row in turn. + """ + + for row in byte_rows: + yield self._bytes_to_values(row) + + def _bytes_to_values(self, bs, width=None): + """Convert a packed row of bytes into a row of values. + Result will be a freshly allocated object, + not shared with the argument. + """ + + if self.bitdepth == 8: + return bytearray(bs) + if self.bitdepth == 16: + return array('H', + struct.unpack('!%dH' % (len(bs) // 2), bs)) + + assert self.bitdepth < 8 + if width is None: + width = self.width + # Samples per byte + spb = 8 // self.bitdepth + out = bytearray() + mask = 2**self.bitdepth - 1 + shifts = [self.bitdepth * i + for i in reversed(list(range(spb)))] + for o in bs: + out.extend([mask & (o >> i) for i in shifts]) + return out[:width] + + def _iter_straight_packed(self, byte_blocks): + """Iterator that undoes the effect of filtering; + yields each row as a sequence of packed bytes. + Assumes input is straightlaced. + `byte_blocks` should be an iterable that yields the raw bytes + in blocks of arbitrary size. + """ + + # length of row, in bytes + rb = self.row_bytes + a = bytearray() + # The previous (reconstructed) scanline. + # None indicates first line of image. + recon = None + for some_bytes in byte_blocks: + a.extend(some_bytes) + while len(a) >= rb + 1: + filter_type = a[0] + scanline = a[1: rb + 1] + del a[: rb + 1] + recon = self.undo_filter(filter_type, scanline, recon) + yield recon + if len(a) != 0: + # :file:format We get here with a file format error: + # when the available bytes (after decompressing) do not + # pack into exact rows. + raise FormatError('Wrong size for decompressed IDAT chunk.') + assert len(a) == 0 + + def validate_signature(self): + """ + If signature (header) has not been read then read and + validate it; otherwise do nothing. + No signature (empty read()) will raise EOFError; + An invalid signature will raise FormatError. + EOFError is raised to make possible the case where + a program can read multiple PNG files from the same stream. + The end of the stream can be distinguished from non-PNG files + or corrupted PNG files. + """ + + if self.signature: + return + self.signature = self.file.read(8) + if len(self.signature) == 0: + raise EOFError("End of PNG stream.") + if self.signature != signature: + raise FormatError("PNG file has invalid signature.") + + def preamble(self, lenient=False): + """ + Extract the image metadata by reading + the initial part of the PNG file up to + the start of the ``IDAT`` chunk. + All the chunks that precede the ``IDAT`` chunk are + read and either processed for metadata or discarded. + + If the optional `lenient` argument evaluates to `True`, + checksum failures will raise warnings rather than exceptions. + """ + + self.validate_signature() + + while True: + if not self.atchunk: + self.atchunk = self._chunk_len_type() + if self.atchunk is None: + raise FormatError('This PNG file has no IDAT chunks.') + if self.atchunk[1] == b'IDAT': + return + self.process_chunk(lenient=lenient) + + def _chunk_len_type(self): + """ + Reads just enough of the input to + determine the next chunk's length and type; + return a (*length*, *type*) pair where *type* is a byte sequence. + If there are no more chunks, ``None`` is returned. + """ + + x = self.file.read(8) + if not x: + return None + if len(x) != 8: + raise FormatError( + 'End of file whilst reading chunk length and type.') + length, type = struct.unpack('!I4s', x) + if length > 2 ** 31 - 1: + raise FormatError('Chunk %s is too large: %d.' % (type, length)) + # Check that all bytes are in valid ASCII range. + # https://www.w3.org/TR/2003/REC-PNG-20031110/#5Chunk-layout + type_bytes = set(bytearray(type)) + if not(type_bytes <= set(range(65, 91)) | set(range(97, 123))): + raise FormatError( + 'Chunk %r has invalid Chunk Type.' + % list(type)) + return length, type + + def process_chunk(self, lenient=False): + """ + Process the next chunk and its data. + This only processes the following chunk types: + ``IHDR``, ``PLTE``, ``bKGD``, ``tRNS``, ``gAMA``, ``sBIT``, ``pHYs``. + All other chunk types are ignored. + + If the optional `lenient` argument evaluates to `True`, + checksum failures will raise warnings rather than exceptions. + """ + + type, data = self.chunk(lenient=lenient) + method = '_process_' + type.decode('ascii') + m = getattr(self, method, None) + if m: + m(data) + + def _process_IHDR(self, data): + # http://www.w3.org/TR/PNG/#11IHDR + if len(data) != 13: + raise FormatError('IHDR chunk has incorrect length.') + (self.width, self.height, self.bitdepth, self.color_type, + self.compression, self.filter, + self.interlace) = struct.unpack("!2I5B", data) + + check_bitdepth_colortype(self.bitdepth, self.color_type) + + if self.compression != 0: + raise FormatError( + "Unknown compression method %d" % self.compression) + if self.filter != 0: + raise FormatError( + "Unknown filter method %d," + " see http://www.w3.org/TR/2003/REC-PNG-20031110/#9Filters ." + % self.filter) + if self.interlace not in (0, 1): + raise FormatError( + "Unknown interlace method %d, see " + "http://www.w3.org/TR/2003/REC-PNG-20031110/#8InterlaceMethods" + " ." + % self.interlace) + + # Derived values + # http://www.w3.org/TR/PNG/#6Colour-values + colormap = bool(self.color_type & 1) + greyscale = not(self.color_type & 2) + alpha = bool(self.color_type & 4) + color_planes = (3, 1)[greyscale or colormap] + planes = color_planes + alpha + + self.colormap = colormap + self.greyscale = greyscale + self.alpha = alpha + self.color_planes = color_planes + self.planes = planes + self.psize = float(self.bitdepth) / float(8) * planes + if int(self.psize) == self.psize: + self.psize = int(self.psize) + self.row_bytes = int(math.ceil(self.width * self.psize)) + # Stores PLTE chunk if present, and is used to check + # chunk ordering constraints. + self.plte = None + # Stores tRNS chunk if present, and is used to check chunk + # ordering constraints. + self.trns = None + # Stores sBIT chunk if present. + self.sbit = None + + def _process_PLTE(self, data): + # http://www.w3.org/TR/PNG/#11PLTE + if self.plte: + warnings.warn("Multiple PLTE chunks present.") + self.plte = data + if len(data) % 3 != 0: + raise FormatError( + "PLTE chunk's length should be a multiple of 3.") + if len(data) > (2 ** self.bitdepth) * 3: + raise FormatError("PLTE chunk is too long.") + if len(data) == 0: + raise FormatError("Empty PLTE is not allowed.") + + def _process_bKGD(self, data): + try: + if self.colormap: + if not self.plte: + warnings.warn( + "PLTE chunk is required before bKGD chunk.") + self.background = struct.unpack('B', data) + else: + self.background = struct.unpack("!%dH" % self.color_planes, + data) + except struct.error: + raise FormatError("bKGD chunk has incorrect length.") + + def _process_tRNS(self, data): + # http://www.w3.org/TR/PNG/#11tRNS + self.trns = data + if self.colormap: + if not self.plte: + warnings.warn("PLTE chunk is required before tRNS chunk.") + else: + if len(data) > len(self.plte) / 3: + # Was warning, but promoted to Error as it + # would otherwise cause pain later on. + raise FormatError("tRNS chunk is too long.") + else: + if self.alpha: + raise FormatError( + "tRNS chunk is not valid with colour type %d." % + self.color_type) + try: + self.transparent = \ + struct.unpack("!%dH" % self.color_planes, data) + except struct.error: + raise FormatError("tRNS chunk has incorrect length.") + + def _process_gAMA(self, data): + try: + self.gamma = struct.unpack("!L", data)[0] / 100000.0 + except struct.error: + raise FormatError("gAMA chunk has incorrect length.") + + def _process_sBIT(self, data): + self.sbit = data + if (self.colormap and len(data) != 3 or + not self.colormap and len(data) != self.planes): + raise FormatError("sBIT chunk has incorrect length.") + + def _process_pHYs(self, data): + # http://www.w3.org/TR/PNG/#11pHYs + self.phys = data + fmt = "!LLB" + if len(data) != struct.calcsize(fmt): + raise FormatError("pHYs chunk has incorrect length.") + self.x_pixels_per_unit, self.y_pixels_per_unit, unit = \ + struct.unpack(fmt, data) + self.unit_is_meter = bool(unit) + + def read(self, lenient=False): + """ + Read the PNG file and decode it. + Returns (`width`, `height`, `rows`, `info`). + + May use excessive memory. + + `rows` is a sequence of rows; + each row is a sequence of values. + + If the optional `lenient` argument evaluates to True, + checksum failures will raise warnings rather than exceptions. + """ + + def iteridat(): + """Iterator that yields all the ``IDAT`` chunks as strings.""" + while True: + type, data = self.chunk(lenient=lenient) + if type == b'IEND': + # http://www.w3.org/TR/PNG/#11IEND + break + if type != b'IDAT': + continue + # type == b'IDAT' + # http://www.w3.org/TR/PNG/#11IDAT + if self.colormap and not self.plte: + warnings.warn("PLTE chunk is required before IDAT chunk") + yield data + + self.preamble(lenient=lenient) + raw = decompress(iteridat()) + + if self.interlace: + def rows_from_interlace(): + """Yield each row from an interlaced PNG.""" + # It's important that this iterator doesn't read + # IDAT chunks until it yields the first row. + bs = bytearray(itertools.chain(*raw)) + arraycode = 'BH'[self.bitdepth > 8] + # Like :meth:`group` but + # producing an array.array object for each row. + values = self._deinterlace(bs) + vpr = self.width * self.planes + for i in range(0, len(values), vpr): + row = array(arraycode, values[i:i+vpr]) + yield row + rows = rows_from_interlace() + else: + rows = self._iter_bytes_to_values(self._iter_straight_packed(raw)) + info = dict() + for attr in 'greyscale alpha planes bitdepth interlace'.split(): + info[attr] = getattr(self, attr) + info['size'] = (self.width, self.height) + for attr in 'gamma transparent background'.split(): + a = getattr(self, attr, None) + if a is not None: + info[attr] = a + if getattr(self, 'x_pixels_per_unit', None): + info['physical'] = Resolution(self.x_pixels_per_unit, + self.y_pixels_per_unit, + self.unit_is_meter) + if self.plte: + info['palette'] = self.palette() + return self.width, self.height, rows, info + + def read_flat(self): + """ + Read a PNG file and decode it into a single array of values. + Returns (*width*, *height*, *values*, *info*). + + May use excessive memory. + + `values` is a single array. + + The :meth:`read` method is more stream-friendly than this, + because it returns a sequence of rows. + """ + + x, y, pixel, info = self.read() + arraycode = 'BH'[info['bitdepth'] > 8] + pixel = array(arraycode, itertools.chain(*pixel)) + return x, y, pixel, info + + def palette(self, alpha='natural'): + """ + Returns a palette that is a sequence of 3-tuples or 4-tuples, + synthesizing it from the ``PLTE`` and ``tRNS`` chunks. + These chunks should have already been processed (for example, + by calling the :meth:`preamble` method). + All the tuples are the same size: + 3-tuples if there is no ``tRNS`` chunk, + 4-tuples when there is a ``tRNS`` chunk. + + Assumes that the image is colour type + 3 and therefore a ``PLTE`` chunk is required. + + If the `alpha` argument is ``'force'`` then an alpha channel is + always added, forcing the result to be a sequence of 4-tuples. + """ + + if not self.plte: + raise FormatError( + "Required PLTE chunk is missing in colour type 3 image.") + plte = group(array('B', self.plte), 3) + if self.trns or alpha == 'force': + trns = array('B', self.trns or []) + trns.extend([255] * (len(plte) - len(trns))) + plte = list(map(operator.add, plte, group(trns, 1))) + return plte + + def asDirect(self): + """ + Returns the image data as a direct representation of + an ``x * y * planes`` array. + This removes the need for callers to deal with + palettes and transparency themselves. + Images with a palette (colour type 3) are converted to RGB or RGBA; + images with transparency (a ``tRNS`` chunk) are converted to + LA or RGBA as appropriate. + When returned in this format the pixel values represent + the colour value directly without needing to refer + to palettes or transparency information. + + Like the :meth:`read` method this method returns a 4-tuple: + + (*width*, *height*, *rows*, *info*) + + This method normally returns pixel values with + the bit depth they have in the source image, but + when the source PNG has an ``sBIT`` chunk it is inspected and + can reduce the bit depth of the result pixels; + pixel values will be reduced according to the bit depth + specified in the ``sBIT`` chunk. + PNG nerds should note a single result bit depth is + used for all channels: + the maximum of the ones specified in the ``sBIT`` chunk. + An RGB565 image will be rescaled to 6-bit RGB666. + + The *info* dictionary that is returned reflects + the `direct` format and not the original source image. + For example, an RGB source image with a ``tRNS`` chunk + to represent a transparent colour, + will start with ``planes=3`` and ``alpha=False`` for the + source image, + but the *info* dictionary returned by this method + will have ``planes=4`` and ``alpha=True`` because + an alpha channel is synthesized and added. + + *rows* is a sequence of rows; + each row being a sequence of values + (like the :meth:`read` method). + + All the other aspects of the image data are not changed. + """ + + self.preamble() + + # Simple case, no conversion necessary. + if not self.colormap and not self.trns and not self.sbit: + return self.read() + + x, y, pixels, info = self.read() + + if self.colormap: + info['colormap'] = False + info['alpha'] = bool(self.trns) + info['bitdepth'] = 8 + info['planes'] = 3 + bool(self.trns) + plte = self.palette() + + def iterpal(pixels): + for row in pixels: + row = [plte[x] for x in row] + yield array('B', itertools.chain(*row)) + pixels = iterpal(pixels) + elif self.trns: + # It would be nice if there was some reasonable way + # of doing this without generating a whole load of + # intermediate tuples. But tuples does seem like the + # easiest way, with no other way clearly much simpler or + # much faster. (Actually, the L to LA conversion could + # perhaps go faster (all those 1-tuples!), but I still + # wonder whether the code proliferation is worth it) + it = self.transparent + maxval = 2 ** info['bitdepth'] - 1 + planes = info['planes'] + info['alpha'] = True + info['planes'] += 1 + typecode = 'BH'[info['bitdepth'] > 8] + + def itertrns(pixels): + for row in pixels: + # For each row we group it into pixels, then form a + # characterisation vector that says whether each + # pixel is opaque or not. Then we convert + # True/False to 0/maxval (by multiplication), + # and add it as the extra channel. + row = group(row, planes) + opa = map(it.__ne__, row) + opa = map(maxval.__mul__, opa) + opa = list(zip(opa)) # convert to 1-tuples + yield array( + typecode, + itertools.chain(*map(operator.add, row, opa))) + pixels = itertrns(pixels) + targetbitdepth = None + if self.sbit: + sbit = struct.unpack('%dB' % len(self.sbit), self.sbit) + targetbitdepth = max(sbit) + if targetbitdepth > info['bitdepth']: + raise Error('sBIT chunk %r exceeds bitdepth %d' % + (sbit, self.bitdepth)) + if min(sbit) <= 0: + raise Error('sBIT chunk %r has a 0-entry' % sbit) + if targetbitdepth: + shift = info['bitdepth'] - targetbitdepth + info['bitdepth'] = targetbitdepth + + def itershift(pixels): + for row in pixels: + yield [p >> shift for p in row] + pixels = itershift(pixels) + return x, y, pixels, info + + def _as_rescale(self, get, targetbitdepth): + """Helper used by :meth:`asRGB8` and :meth:`asRGBA8`.""" + + width, height, pixels, info = get() + maxval = 2**info['bitdepth'] - 1 + targetmaxval = 2**targetbitdepth - 1 + factor = float(targetmaxval) / float(maxval) + info['bitdepth'] = targetbitdepth + + def iterscale(): + for row in pixels: + yield [int(round(x * factor)) for x in row] + if maxval == targetmaxval: + return width, height, pixels, info + else: + return width, height, iterscale(), info + + def asRGB8(self): + """ + Return the image data as an RGB pixels with 8-bits per sample. + This is like the :meth:`asRGB` method except that + this method additionally rescales the values so that + they are all between 0 and 255 (8-bit). + In the case where the source image has a bit depth < 8 + the transformation preserves all the information; + where the source image has bit depth > 8, then + rescaling to 8-bit values loses precision. + No dithering is performed. + Like :meth:`asRGB`, + an alpha channel in the source image will raise an exception. + + This function returns a 4-tuple: + (*width*, *height*, *rows*, *info*). + *width*, *height*, *info* are as per the :meth:`read` method. + + *rows* is the pixel data as a sequence of rows. + """ + + return self._as_rescale(self.asRGB, 8) + + def asRGBA8(self): + """ + Return the image data as RGBA pixels with 8-bits per sample. + This method is similar to :meth:`asRGB8` and :meth:`asRGBA`: + The result pixels have an alpha channel, *and* + values are rescaled to the range 0 to 255. + The alpha channel is synthesized if necessary + (with a small speed penalty). + """ + + return self._as_rescale(self.asRGBA, 8) + + def asRGB(self): + """ + Return image as RGB pixels. + RGB colour images are passed through unchanged; + greyscales are expanded into RGB triplets + (there is a small speed overhead for doing this). + + An alpha channel in the source image will raise an exception. + + The return values are as for the :meth:`read` method except that + the *info* reflect the returned pixels, not the source image. + In particular, + for this method ``info['greyscale']`` will be ``False``. + """ + + width, height, pixels, info = self.asDirect() + if info['alpha']: + raise Error("will not convert image with alpha channel to RGB") + if not info['greyscale']: + return width, height, pixels, info + info['greyscale'] = False + info['planes'] = 3 + + if info['bitdepth'] > 8: + def newarray(): + return array('H', [0]) + else: + def newarray(): + return bytearray([0]) + + def iterrgb(): + for row in pixels: + a = newarray() * 3 * width + for i in range(3): + a[i::3] = row + yield a + return width, height, iterrgb(), info + + def asRGBA(self): + """ + Return image as RGBA pixels. + Greyscales are expanded into RGB triplets; + an alpha channel is synthesized if necessary. + The return values are as for the :meth:`read` method except that + the *info* reflect the returned pixels, not the source image. + In particular, for this method + ``info['greyscale']`` will be ``False``, and + ``info['alpha']`` will be ``True``. + """ + + width, height, pixels, info = self.asDirect() + if info['alpha'] and not info['greyscale']: + return width, height, pixels, info + typecode = 'BH'[info['bitdepth'] > 8] + maxval = 2**info['bitdepth'] - 1 + maxbuffer = struct.pack('=' + typecode, maxval) * 4 * width + + if info['bitdepth'] > 8: + def newarray(): + return array('H', maxbuffer) + else: + def newarray(): + return bytearray(maxbuffer) + + if info['alpha'] and info['greyscale']: + # LA to RGBA + def convert(): + for row in pixels: + # Create a fresh target row, then copy L channel + # into first three target channels, and A channel + # into fourth channel. + a = newarray() + convert_la_to_rgba(row, a) + yield a + elif info['greyscale']: + # L to RGBA + def convert(): + for row in pixels: + a = newarray() + convert_l_to_rgba(row, a) + yield a + else: + assert not info['alpha'] and not info['greyscale'] + # RGB to RGBA + + def convert(): + for row in pixels: + a = newarray() + convert_rgb_to_rgba(row, a) + yield a + info['alpha'] = True + info['greyscale'] = False + info['planes'] = 4 + return width, height, convert(), info + + +def decompress(data_blocks): + """ + `data_blocks` should be an iterable that + yields the compressed data (from the ``IDAT`` chunks). + This yields decompressed byte strings. + """ + + # Currently, with no max_length parameter to decompress, + # this routine will do one yield per IDAT chunk: Not very + # incremental. + d = zlib.decompressobj() + # Each IDAT chunk is passed to the decompressor, then any + # remaining state is decompressed out. + for data in data_blocks: + # :todo: add a max_length argument here to limit output size. + yield bytearray(d.decompress(data)) + yield bytearray(d.flush()) + + +def check_bitdepth_colortype(bitdepth, colortype): + """ + Check that `bitdepth` and `colortype` are both valid, + and specified in a valid combination. + Returns (None) if valid, raise an Exception if not valid. + """ + + if bitdepth not in (1, 2, 4, 8, 16): + raise FormatError("invalid bit depth %d" % bitdepth) + if colortype not in (0, 2, 3, 4, 6): + raise FormatError("invalid colour type %d" % colortype) + # Check indexed (palettized) images have 8 or fewer bits + # per pixel; check only indexed or greyscale images have + # fewer than 8 bits per pixel. + if colortype & 1 and bitdepth > 8: + raise FormatError( + "Indexed images (colour type %d) cannot" + " have bitdepth > 8 (bit depth %d)." + " See http://www.w3.org/TR/2003/REC-PNG-20031110/#table111 ." + % (bitdepth, colortype)) + if bitdepth < 8 and colortype not in (0, 3): + raise FormatError( + "Illegal combination of bit depth (%d)" + " and colour type (%d)." + " See http://www.w3.org/TR/2003/REC-PNG-20031110/#table111 ." + % (bitdepth, colortype)) + + +def is_natural(x): + """A non-negative integer.""" + try: + is_integer = int(x) == x + except (TypeError, ValueError): + return False + return is_integer and x >= 0 + + +def undo_filter_sub(filter_unit, scanline, previous, result): + """Undo sub filter.""" + + ai = 0 + # Loops starts at index fu. Observe that the initial part + # of the result is already filled in correctly with + # scanline. + for i in range(filter_unit, len(result)): + x = scanline[i] + a = result[ai] + result[i] = (x + a) & 0xff + ai += 1 + + +def undo_filter_up(filter_unit, scanline, previous, result): + """Undo up filter.""" + + for i in range(len(result)): + x = scanline[i] + b = previous[i] + result[i] = (x + b) & 0xff + + +def undo_filter_average(filter_unit, scanline, previous, result): + """Undo up filter.""" + + ai = -filter_unit + for i in range(len(result)): + x = scanline[i] + if ai < 0: + a = 0 + else: + a = result[ai] + b = previous[i] + result[i] = (x + ((a + b) >> 1)) & 0xff + ai += 1 + + +def undo_filter_paeth(filter_unit, scanline, previous, result): + """Undo Paeth filter.""" + + # Also used for ci. + ai = -filter_unit + for i in range(len(result)): + x = scanline[i] + if ai < 0: + a = c = 0 + else: + a = result[ai] + c = previous[ai] + b = previous[i] + p = a + b - c + pa = abs(p - a) + pb = abs(p - b) + pc = abs(p - c) + if pa <= pb and pa <= pc: + pr = a + elif pb <= pc: + pr = b + else: + pr = c + result[i] = (x + pr) & 0xff + ai += 1 + + +def convert_la_to_rgba(row, result): + for i in range(3): + result[i::4] = row[0::2] + result[3::4] = row[1::2] + + +def convert_l_to_rgba(row, result): + """ + Convert a grayscale image to RGBA. + This method assumes the alpha channel in result is + already correctly initialized. + """ + for i in range(3): + result[i::4] = row + + +def convert_rgb_to_rgba(row, result): + """ + Convert an RGB image to RGBA. + This method assumes the alpha channel in result is + already correctly initialized. + """ + for i in range(3): + result[i::4] = row[i::3] + + +# Only reason to include this in this module is that +# several utilities need it, and it is small. +def binary_stdin(): + """ + A sys.stdin that returns bytes. + """ + + return sys.stdin.buffer + + +def binary_stdout(): + """ + A sys.stdout that accepts bytes. + """ + + stdout = sys.stdout.buffer + + # On Windows the C runtime file orientation needs changing. + if sys.platform == "win32": + import msvcrt + import os + msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) + + return stdout + + +def cli_open(path): + if path == "-": + return binary_stdin() + return open(path, "rb") + + +def main(argv): + """ + Run command line PNG. + Which reports version. + """ + print(__version__, __file__) + + +if __name__ == '__main__': + try: + main(sys.argv) + except Error as e: + print(e, file=sys.stderr) diff --git a/tools/pokemontools/__init__.py b/tools/pokemontools/__init__.py deleted file mode 100644 index a3e759000..000000000 --- a/tools/pokemontools/__init__.py +++ /dev/null @@ -1 +0,0 @@ -# A subset of https://github.com/pret/pokemon-reverse-engineering-tools diff --git a/tools/pokemontools/gfx.py b/tools/pokemontools/gfx.py deleted file mode 100644 index 2979b5a79..000000000 --- a/tools/pokemontools/gfx.py +++ /dev/null @@ -1,938 +0,0 @@ -# -*- coding: utf-8 -*- - -import os -import sys -import png -from math import sqrt, floor, ceil -import argparse -import operator - -from lz import Compressed, Decompressed - - -def split(list_, interval): - """ - Split a list by length. - """ - for i in xrange(0, len(list_), interval): - j = min(i + interval, len(list_)) - yield list_[i:j] - - -def hex_dump(data, length=0x10): - """ - just use hexdump -C - """ - margin = len('%x' % len(data)) - output = [] - address = 0 - for line in split(data, length): - output += [ - hex(address)[2:].zfill(margin) + - ' | ' + - ' '.join('%.2x' % byte for byte in line) - ] - address += length - return '\n'.join(output) - - -def get_tiles(image): - """ - Split a 2bpp image into 8x8 tiles. - """ - return list(split(image, 0x10)) - -def connect(tiles): - """ - Combine 8x8 tiles into a 2bpp image. - """ - return [byte for tile in tiles for byte in tile] - -def transpose(tiles, width=None): - """ - Transpose a tile arrangement along line y=-x. - - 00 01 02 03 04 05 00 06 0c 12 18 1e - 06 07 08 09 0a 0b 01 07 0d 13 19 1f - 0c 0d 0e 0f 10 11 <-> 02 08 0e 14 1a 20 - 12 13 14 15 16 17 03 09 0f 15 1b 21 - 18 19 1a 1b 1c 1d 04 0a 10 16 1c 22 - 1e 1f 20 21 22 23 05 0b 11 17 1d 23 - - 00 01 02 03 00 04 08 - 04 05 06 07 <-> 01 05 09 - 08 09 0a 0b 02 06 0a - 03 07 0b - """ - if width == None: - width = int(sqrt(len(tiles))) # assume square image - tiles = sorted(enumerate(tiles), key= lambda (i, tile): i % width) - return [tile for i, tile in tiles] - -def transpose_tiles(image, width=None): - return connect(transpose(get_tiles(image), width)) - -def interleave(tiles, width): - """ - 00 01 02 03 04 05 00 02 04 06 08 0a - 06 07 08 09 0a 0b 01 03 05 07 09 0b - 0c 0d 0e 0f 10 11 --> 0c 0e 10 12 14 16 - 12 13 14 15 16 17 0d 0f 11 13 15 17 - 18 19 1a 1b 1c 1d 18 1a 1c 1e 20 22 - 1e 1f 20 21 22 23 19 1b 1d 1f 21 23 - """ - interleaved = [] - left, right = split(tiles[::2], width), split(tiles[1::2], width) - for l, r in zip(left, right): - interleaved += l + r - return interleaved - -def deinterleave(tiles, width): - """ - 00 02 04 06 08 0a 00 01 02 03 04 05 - 01 03 05 07 09 0b 06 07 08 09 0a 0b - 0c 0e 10 12 14 16 --> 0c 0d 0e 0f 10 11 - 0d 0f 11 13 15 17 12 13 14 15 16 17 - 18 1a 1c 1e 20 22 18 19 1a 1b 1c 1d - 19 1b 1d 1f 21 23 1e 1f 20 21 22 23 - """ - deinterleaved = [] - rows = list(split(tiles, width)) - for left, right in zip(rows[::2], rows[1::2]): - for l, r in zip(left, right): - deinterleaved += [l, r] - return deinterleaved - -def interleave_tiles(image, width): - return connect(interleave(get_tiles(image), width)) - -def deinterleave_tiles(image, width): - return connect(deinterleave(get_tiles(image), width)) - - -def condense_image_to_map(image, pic=0): - """ - Reduce an image of adjacent frames to an image containing a base frame and any unrepeated tiles. - Returns the new image and the corresponding tilemap used to reconstruct the input image. - - If is 0, ignore the concept of frames. This behavior might be better off as another function. - """ - tiles = get_tiles(image) - new_tiles, tilemap = condense_tiles_to_map(tiles, pic) - new_image = connect(new_tiles) - return new_image, tilemap - -def condense_tiles_to_map(tiles, pic=0): - """ - Reduce a sequence of tiles representing adjacent frames to a base frame and any unrepeated tiles. - Returns the new tiles and the corresponding tilemap used to reconstruct the input tile sequence. - - If is 0, ignore the concept of frames. This behavior might be better off as another function. - """ - - # Leave the first frame intact for pics. - new_tiles = tiles[:pic] - tilemap = range(pic) - - for i, tile in enumerate(tiles[pic:]): - if tile not in new_tiles: - new_tiles.append(tile) - - if pic: - # Match the first frame exactly where possible. - # This reduces the space needed to replace tiles in pic animations. - # For example, if a tile is repeated twice in the first frame, - # but at the same relative index as the second tile, use the second index. - # When creating a bitmask later, the second index would not require a replacement, but the first index would have. - pic_i = i % pic - if tile == new_tiles[pic_i]: - tilemap.append(pic_i) - else: - tilemap.append(new_tiles.index(tile)) - else: - tilemap.append(new_tiles.index(tile)) - return new_tiles, tilemap - -def test_condense_tiles_to_map(): - test = condense_tiles_to_map(list('abcadbae')) - if test != (list('abcde'), [0, 1, 2, 0, 3, 1, 0, 4]): - raise Exception(test) - test = condense_tiles_to_map(list('abcadbae'), 2) - if test != (list('abcde'), [0, 1, 2, 0, 3, 1, 0, 4]): - raise Exception(test) - test = condense_tiles_to_map(list('abcadbae'), 4) - if test != (list('abcade'), [0, 1, 2, 3, 4, 1, 0, 5]): - raise Exception(test) - test = condense_tiles_to_map(list('abcadbea'), 4) - if test != (list('abcade'), [0, 1, 2, 3, 4, 1, 5, 3]): - raise Exception(test) - - -def to_file(filename, data): - """ - Apparently open(filename, 'wb').write(bytearray(data)) won't work. - """ - file = open(filename, 'wb') - for byte in data: - file.write('%c' % byte) - file.close() - - -def decompress_file(filein, fileout=None): - image = bytearray(open(filein).read()) - de = Decompressed(image) - - if fileout == None: - fileout = os.path.splitext(filein)[0] - to_file(fileout, de.output) - - -def compress_file(filein, fileout=None): - image = bytearray(open(filein).read()) - lz = Compressed(image) - - if fileout == None: - fileout = filein + '.lz' - to_file(fileout, lz.output) - - -def bin_to_rgb(word): - red = word & 0b11111 - word >>= 5 - green = word & 0b11111 - word >>= 5 - blue = word & 0b11111 - return (red, green, blue) - -def convert_binary_pal_to_text_by_filename(filename): - pal = bytearray(open(filename).read()) - return convert_binary_pal_to_text(pal) - -def convert_binary_pal_to_text(pal): - output = '' - words = [hi * 0x100 + lo for lo, hi in zip(pal[::2], pal[1::2])] - for word in words: - red, green, blue = ['%.2d' % c for c in bin_to_rgb(word)] - output += '\tRGB ' + ', '.join((red, green, blue)) - output += '\n' - return output - -def read_rgb_macros(lines): - colors = [] - for line in lines: - macro = line.split(" ")[0].strip() - if macro == 'RGB': - params = ' '.join(line.split(" ")[1:]).split(',') - red, green, blue = [int(v) for v in params] - colors += [[red, green, blue]] - return colors - - -def rewrite_binary_pals_to_text(filenames): - for filename in filenames: - pal_text = convert_binary_pal_to_text_by_filename(filename) - with open(filename, 'w') as out: - out.write(pal_text) - - -def flatten(planar): - """ - Flatten planar 2bpp image data into a quaternary pixel map. - """ - strips = [] - for bottom, top in split(planar, 2): - bottom = bottom - top = top - strip = [] - for i in xrange(7,-1,-1): - color = ( - (bottom >> i & 1) + - (top *2 >> i & 2) - ) - strip += [color] - strips += strip - return strips - -def to_lines(image, width): - """ - Convert a tiled quaternary pixel map to lines of quaternary pixels. - """ - tile_width = 8 - tile_height = 8 - num_columns = width / tile_width - height = len(image) / width - - lines = [] - for cur_line in xrange(height): - tile_row = cur_line / tile_height - line = [] - for column in xrange(num_columns): - anchor = ( - num_columns * tile_row * tile_width * tile_height + - column * tile_width * tile_height + - cur_line % tile_height * tile_width - ) - line += image[anchor : anchor + tile_width] - lines += [line] - return lines - - -def dmg2rgb(word): - """ - For PNGs. - """ - def shift(value): - while True: - yield value & (2**5 - 1) - value >>= 5 - word = shift(word) - # distribution is less even w/ << 3 - red, green, blue = [int(color * 8.25) for color in [word.next() for _ in xrange(3)]] - alpha = 255 - return (red, green, blue, alpha) - - -def rgb_to_dmg(color): - """ - For PNGs. - """ - word = (color['r'] / 8) - word += (color['g'] / 8) << 5 - word += (color['b'] / 8) << 10 - return word - - -def pal_to_png(filename): - """ - Interpret a .pal file as a png palette. - """ - with open(filename) as rgbs: - colors = read_rgb_macros(rgbs.readlines()) - a = 255 - palette = [] - for color in colors: - # even distribution over 000-255 - r, g, b = [int(hue * 8.25) for hue in color] - palette += [(r, g, b, a)] - white = (255,255,255,255) - black = (000,000,000,255) - if white not in palette and len(palette) < 4: - palette = [white] + palette - if black not in palette and len(palette) < 4: - palette = palette + [black] - return palette - - -def png_to_rgb(palette): - """ - Convert a png palette to rgb macros. - """ - output = '' - for color in palette: - r, g, b = [color[c] / 8 for c in 'rgb'] - output += '\tRGB ' + ', '.join(['%.2d' % hue for hue in (r, g, b)]) - output += '\n' - return output - - -def read_filename_arguments(filename): - """ - Infer graphics conversion arguments given a filename. - - Arguments are separated with '.'. - """ - parsed_arguments = {} - - int_arguments = { - 'w': 'width', - 'h': 'height', - 't': 'tile_padding', - } - arguments = os.path.splitext(filename)[0].lstrip('.').split('.')[1:] - for argument in arguments: - - # Check for integer arguments first (i.e. "w128"). - arg = argument[0] - param = argument[1:] - if param.isdigit(): - arg = int_arguments.get(arg, False) - if arg: - parsed_arguments[arg] = int(param) - - elif argument == 'arrange': - parsed_arguments['norepeat'] = True - parsed_arguments['tilemap'] = True - - # Pic dimensions (i.e. "6x6"). - elif 'x' in argument and any(map(str.isdigit, argument)): - w, h = argument.split('x') - if w.isdigit() and h.isdigit(): - parsed_arguments['pic_dimensions'] = (int(w), int(h)) - - else: - parsed_arguments[argument] = True - - return parsed_arguments - - -def export_2bpp_to_png(filein, fileout=None, pal_file=None, height=0, width=0, tile_padding=0, pic_dimensions=None, **kwargs): - - if fileout == None: - fileout = os.path.splitext(filein)[0] + '.png' - - image = open(filein, 'rb').read() - - arguments = { - 'width': width, - 'height': height, - 'pal_file': pal_file, - 'tile_padding': tile_padding, - 'pic_dimensions': pic_dimensions, - } - arguments.update(read_filename_arguments(filein)) - - if pal_file == None: - if os.path.exists(os.path.splitext(fileout)[0]+'.pal'): - arguments['pal_file'] = os.path.splitext(fileout)[0]+'.pal' - - result = convert_2bpp_to_png(image, **arguments) - width, height, palette, greyscale, bitdepth, px_map = result - - w = png.Writer( - width, - height, - palette=palette, - compression=9, - greyscale=greyscale, - bitdepth=bitdepth - ) - with open(fileout, 'wb') as f: - w.write(f, px_map) - - -def convert_2bpp_to_png(image, **kwargs): - """ - Convert a planar 2bpp graphic to png. - """ - - image = bytearray(image) - - pad_color = bytearray([0]) - - width = kwargs.get('width', 0) - height = kwargs.get('height', 0) - tile_padding = kwargs.get('tile_padding', 0) - pic_dimensions = kwargs.get('pic_dimensions', None) - pal_file = kwargs.get('pal_file', None) - interleave = kwargs.get('interleave', False) - - # Width must be specified to interleave. - if interleave and width: - image = interleave_tiles(image, width / 8) - - # Pad the image by a given number of tiles if asked. - image += pad_color * 0x10 * tile_padding - - # Some images are transposed in blocks. - if pic_dimensions: - w, h = pic_dimensions - if not width: width = w * 8 - - pic_length = w * h * 0x10 - - trailing = len(image) % pic_length - - pic = [] - for i in xrange(0, len(image) - trailing, pic_length): - pic += transpose_tiles(image[i:i+pic_length], h) - image = bytearray(pic) + image[len(image) - trailing:] - - # Pad out trailing lines. - image += pad_color * 0x10 * ((w - (len(image) / 0x10) % h) % w) - - def px_length(img): - return len(img) * 4 - def tile_length(img): - return len(img) * 4 / (8*8) - - if width and height: - tile_width = width / 8 - more_tile_padding = (tile_width - (tile_length(image) % tile_width or tile_width)) - image += pad_color * 0x10 * more_tile_padding - - elif width and not height: - tile_width = width / 8 - more_tile_padding = (tile_width - (tile_length(image) % tile_width or tile_width)) - image += pad_color * 0x10 * more_tile_padding - height = px_length(image) / width - - elif height and not width: - tile_height = height / 8 - more_tile_padding = (tile_height - (tile_length(image) % tile_height or tile_height)) - image += pad_color * 0x10 * more_tile_padding - width = px_length(image) / height - - # at least one dimension should be given - if width * height != px_length(image): - # look for possible combos of width/height that would form a rectangle - matches = [] - # Height need not be divisible by 8, but width must. - # See pokered gfx/minimize_pic.1bpp. - for w in range(8, px_length(image) / 2 + 1, 8): - h = px_length(image) / w - if w * h == px_length(image): - matches += [(w, h)] - # go for the most square image - if len(matches): - width, height = sorted(matches, key= lambda (w, h): (h % 8 != 0, w + h))[0] # favor height - else: - raise Exception, 'Image can\'t be divided into tiles (%d px)!' % (px_length(image)) - - # convert tiles to lines - lines = to_lines(flatten(image), width) - - if pal_file == None: - palette = None - greyscale = True - bitdepth = 2 - px_map = [[3 - pixel for pixel in line] for line in lines] - - else: # gbc color - palette = pal_to_png(pal_file) - greyscale = False - bitdepth = 8 - px_map = [[pixel for pixel in line] for line in lines] - - return width, height, palette, greyscale, bitdepth, px_map - - -def get_pic_animation(tmap, w, h): - """ - Generate pic animation data from a combined tilemap of each frame. - """ - frame_text = '' - bitmask_text = '' - - frames = list(split(tmap, w * h)) - base = frames.pop(0) - bitmasks = [] - - for i in xrange(len(frames)): - frame_text += '\tdw .frame{}\n'.format(i + 1) - - for i, frame in enumerate(frames): - bitmask = map(operator.ne, frame, base) - if bitmask not in bitmasks: - bitmasks.append(bitmask) - which_bitmask = bitmasks.index(bitmask) - - mask = iter(bitmask) - masked_frame = filter(lambda _: mask.next(), frame) - - frame_text += '.frame{}\n'.format(i + 1) - frame_text += '\tdb ${:02x} ; bitmask\n'.format(which_bitmask) - if masked_frame: - frame_text += '\tdb {}\n'.format(', '.join( - map('${:02x}'.format, masked_frame) - )) - - for i, bitmask in enumerate(bitmasks): - bitmask_text += '; {}\n'.format(i) - for byte in split(bitmask, 8): - byte = int(''.join(map(int.__repr__, reversed(byte))), 2) - bitmask_text += '\tdb %{:08b}\n'.format(byte) - - return frame_text, bitmask_text - - -def export_png_to_2bpp(filein, fileout=None, palout=None, **kwargs): - - arguments = { - 'tile_padding': 0, - 'pic_dimensions': None, - 'animate': False, - 'stupid_bitmask_hack': [], - } - arguments.update(kwargs) - arguments.update(read_filename_arguments(filein)) - - image, arguments = png_to_2bpp(filein, **arguments) - - if fileout == None: - fileout = os.path.splitext(filein)[0] + '.2bpp' - to_file(fileout, image) - - tmap = arguments.get('tmap') - - if tmap != None and arguments['animate'] and arguments['pic_dimensions']: - # Generate pic animation data. - frame_text, bitmask_text = get_pic_animation(tmap, *arguments['pic_dimensions']) - - frames_path = os.path.join(os.path.split(fileout)[0], 'frames.asm') - with open(frames_path, 'w') as out: - out.write(frame_text) - - bitmask_path = os.path.join(os.path.split(fileout)[0], 'bitmask.asm') - - # The following Pokemon have a bitmask dummied out. - for exception in arguments['stupid_bitmask_hack']: - if exception in bitmask_path: - bitmasks = bitmask_text.split(';') - bitmasks[-1] = bitmasks[-1].replace('1', '0') - bitmask_text = ';'.join(bitmasks) - - with open(bitmask_path, 'w') as out: - out.write(bitmask_text) - - elif tmap != None and arguments.get('tilemap', False): - tilemap_path = os.path.splitext(fileout)[0] + '.tilemap' - to_file(tilemap_path, tmap) - - palette = arguments.get('palette') - if palout == None: - palout = os.path.splitext(fileout)[0] + '.pal' - export_palette(palette, palout) - - -def get_image_padding(width, height, wstep=8, hstep=8): - - padding = { - 'left': 0, - 'right': 0, - 'top': 0, - 'bottom': 0, - } - - if width % wstep and width >= wstep: - pad = float(width % wstep) / 2 - padding['left'] = int(ceil(pad)) - padding['right'] = int(floor(pad)) - - if height % hstep and height >= hstep: - pad = float(height % hstep) / 2 - padding['top'] = int(ceil(pad)) - padding['bottom'] = int(floor(pad)) - - return padding - - -def png_to_2bpp(filein, **kwargs): - """ - Convert a png image to planar 2bpp. - """ - - arguments = { - 'tile_padding': 0, - 'pic_dimensions': False, - 'interleave': False, - 'norepeat': False, - 'tilemap': False, - } - arguments.update(kwargs) - - if type(filein) is str: - filein = open(filein) - - assert type(filein) is file - - width, height, rgba, info = png.Reader(filein).asRGBA8() - - # png.Reader returns flat pixel data. Nested is easier to work with - len_px = len('rgba') - image = [] - palette = [] - for line in rgba: - newline = [] - for px in xrange(0, len(line), len_px): - color = dict(zip('rgba', line[px:px+len_px])) - if color not in palette: - if len(palette) < 4: - palette += [color] - else: - # TODO Find the nearest match - print 'WARNING: %s: Color %s truncated to' % (filein, color), - color = sorted(palette, key=lambda x: sum(x.values()))[0] - print color - newline += [color] - image += [newline] - - assert len(palette) <= 4, '%s: palette should be 4 colors, is really %d (%s)' % (filein, len(palette), palette) - - # Pad out smaller palettes with greyscale colors - greyscale = { - 'black': { 'r': 0x00, 'g': 0x00, 'b': 0x00, 'a': 0xff }, - 'grey': { 'r': 0x55, 'g': 0x55, 'b': 0x55, 'a': 0xff }, - 'gray': { 'r': 0xaa, 'g': 0xaa, 'b': 0xaa, 'a': 0xff }, - 'white': { 'r': 0xff, 'g': 0xff, 'b': 0xff, 'a': 0xff }, - } - preference = 'white', 'black', 'grey', 'gray' - for hue in map(greyscale.get, preference): - if len(palette) >= 4: - break - if hue not in palette: - palette += [hue] - - palette.sort(key=lambda x: sum(x.values())) - - # Game Boy palette order - palette.reverse() - - # Map pixels to quaternary color ids - padding = get_image_padding(width, height) - width += padding['left'] + padding['right'] - height += padding['top'] + padding['bottom'] - pad = bytearray([0]) - - qmap = [] - qmap += pad * width * padding['top'] - for line in image: - qmap += pad * padding['left'] - for color in line: - qmap += [palette.index(color)] - qmap += pad * padding['right'] - qmap += pad * width * padding['bottom'] - - # Graphics are stored in tiles instead of lines - tile_width = 8 - tile_height = 8 - num_columns = max(width, tile_width) / tile_width - num_rows = max(height, tile_height) / tile_height - image = [] - - for row in xrange(num_rows): - for column in xrange(num_columns): - - # Split it up into strips to convert to planar data - for strip in xrange(min(tile_height, height)): - anchor = ( - row * num_columns * tile_width * tile_height + - column * tile_width + - strip * width - ) - line = qmap[anchor : anchor + tile_width] - bottom, top = 0, 0 - for bit, quad in enumerate(line): - bottom += (quad & 1) << (7 - bit) - top += (quad /2 & 1) << (7 - bit) - image += [bottom, top] - - dim = arguments['pic_dimensions'] - if dim: - if type(dim) in (tuple, list): - w, h = dim - else: - # infer dimensions based on width. - w = width / tile_width - h = height / tile_height - if h % w == 0: - h = w - - tiles = get_tiles(image) - pic_length = w * h - tile_width = width / 8 - trailing = len(tiles) % pic_length - new_image = [] - for block in xrange(len(tiles) / pic_length): - offset = (h * tile_width) * ((block * w) / tile_width) + ((block * w) % tile_width) - pic = [] - for row in xrange(h): - index = offset + (row * tile_width) - pic += tiles[index:index + w] - new_image += transpose(pic, w) - new_image += tiles[len(tiles) - trailing:] - image = connect(new_image) - - # Remove any tile padding used to make the png rectangular. - image = image[:len(image) - arguments['tile_padding'] * 0x10] - - tmap = None - - if arguments['interleave']: - image = deinterleave_tiles(image, num_columns) - - if arguments['pic_dimensions']: - image, tmap = condense_image_to_map(image, w * h) - elif arguments['norepeat']: - image, tmap = condense_image_to_map(image) - if not arguments['tilemap']: - tmap = None - - arguments.update({ 'palette': palette, 'tmap': tmap, }) - - return image, arguments - - -def export_palette(palette, filename): - """ - Export a palette from png to rgb macros in a .pal file. - """ - - if os.path.exists(filename): - - # Pic palettes are 2 colors (black/white are added later). - with open(filename) as rgbs: - colors = read_rgb_macros(rgbs.readlines()) - - if len(colors) == 2: - palette = palette[1:3] - - text = png_to_rgb(palette) - with open(filename, 'w') as out: - out.write(text) - - -def png_to_lz(filein): - - name = os.path.splitext(filein)[0] - - export_png_to_2bpp(filein) - image = open(name+'.2bpp', 'rb').read() - to_file(name+'.2bpp'+'.lz', Compressed(image).output) - - -def convert_2bpp_to_1bpp(data): - """ - Convert planar 2bpp image data to 1bpp. Assume images are two colors. - """ - return data[::2] - -def convert_1bpp_to_2bpp(data): - """ - Convert 1bpp image data to planar 2bpp (black/white). - """ - output = [] - for i in data: - output += [i, i] - return output - - -def export_2bpp_to_1bpp(filename): - name, extension = os.path.splitext(filename) - image = open(filename, 'rb').read() - image = convert_2bpp_to_1bpp(image) - to_file(name + '.1bpp', image) - -def export_1bpp_to_2bpp(filename): - name, extension = os.path.splitext(filename) - image = open(filename, 'rb').read() - image = convert_1bpp_to_2bpp(image) - to_file(name + '.2bpp', image) - - -def export_1bpp_to_png(filename, fileout=None): - - if fileout == None: - fileout = os.path.splitext(filename)[0] + '.png' - - arguments = read_filename_arguments(filename) - - image = open(filename, 'rb').read() - image = convert_1bpp_to_2bpp(image) - - result = convert_2bpp_to_png(image, **arguments) - width, height, palette, greyscale, bitdepth, px_map = result - - w = png.Writer(width, height, palette=palette, compression=9, greyscale=greyscale, bitdepth=bitdepth) - with open(fileout, 'wb') as f: - w.write(f, px_map) - - -def export_png_to_1bpp(filename, fileout=None): - - if fileout == None: - fileout = os.path.splitext(filename)[0] + '.1bpp' - - arguments = read_filename_arguments(filename) - image = png_to_1bpp(filename, **arguments) - - to_file(fileout, image) - -def png_to_1bpp(filename, **kwargs): - image, kwargs = png_to_2bpp(filename, **kwargs) - return convert_2bpp_to_1bpp(image) - - -def convert_to_2bpp(filenames=[]): - for filename in filenames: - filename, name, extension = try_decompress(filename) - if extension == '.1bpp': - export_1bpp_to_2bpp(filename) - elif extension == '.2bpp': - pass - elif extension == '.png': - export_png_to_2bpp(filename) - else: - raise Exception, "Don't know how to convert {} to 2bpp!".format(filename) - -def convert_to_1bpp(filenames=[]): - for filename in filenames: - filename, name, extension = try_decompress(filename) - if extension == '.1bpp': - pass - elif extension == '.2bpp': - export_2bpp_to_1bpp(filename) - elif extension == '.png': - export_png_to_1bpp(filename) - else: - raise Exception, "Don't know how to convert {} to 1bpp!".format(filename) - -def convert_to_png(filenames=[]): - for filename in filenames: - filename, name, extension = try_decompress(filename) - if extension == '.1bpp': - export_1bpp_to_png(filename) - elif extension == '.2bpp': - export_2bpp_to_png(filename) - elif extension == '.png': - pass - else: - raise Exception, "Don't know how to convert {} to png!".format(filename) - -def compress(filenames=[]): - for filename in filenames: - data = open(filename, 'rb').read() - lz_data = Compressed(data).output - to_file(filename + '.lz', lz_data) - -def decompress(filenames=[]): - for filename in filenames: - name, extension = os.path.splitext(filename) - lz_data = open(filename, 'rb').read() - data = Decompressed(lz_data).output - to_file(name, data) - -def try_decompress(filename): - """ - Try to decompress a graphic when determining the filetype. - This skips the manual unlz step when attempting - to convert lz-compressed graphics to png. - """ - name, extension = os.path.splitext(filename) - if extension == '.lz': - decompress([filename]) - filename = name - name, extension = os.path.splitext(filename) - return filename, name, extension - - -def main(): - ap = argparse.ArgumentParser() - ap.add_argument('mode') - ap.add_argument('filenames', nargs='*') - args = ap.parse_args() - - method = { - '2bpp': convert_to_2bpp, - '1bpp': convert_to_1bpp, - 'png': convert_to_png, - 'lz': compress, - 'unlz': decompress, - }.get(args.mode, None) - - if method == None: - raise Exception, "Unknown conversion method!" - - method(args.filenames) - -if __name__ == "__main__": - main() diff --git a/tools/pokemontools/lz.py b/tools/pokemontools/lz.py deleted file mode 100644 index aef5c641a..000000000 --- a/tools/pokemontools/lz.py +++ /dev/null @@ -1,580 +0,0 @@ -# -*- coding: utf-8 -*- -""" -Pokemon Crystal data de/compression. -""" - -""" -A rundown of Pokemon Crystal's compression scheme: - -Control commands occupy bits 5-7. -Bits 0-4 serve as the first parameter for each command. -""" -lz_commands = { - 'literal': 0, # n values for n bytes - 'iterate': 1, # one value for n bytes - 'alternate': 2, # alternate two values for n bytes - 'blank': 3, # zero for n bytes -} - -""" -Repeater commands repeat any data that was just decompressed. -They take an additional signed parameter to mark a relative starting point. -These wrap around (positive from the start, negative from the current position). -""" -lz_commands.update({ - 'repeat': 4, # n bytes starting from s - 'flip': 5, # n bytes in reverse bit order starting from s - 'reverse': 6, # n bytes backwards starting from s -}) - -""" -The long command is used when 5 bits aren't enough. Bits 2-4 contain a new control code. -Bits 0-1 are appended to a new byte as 8-9, allowing a 10-bit parameter. -""" -lz_commands.update({ - 'long': 7, # n is now 10 bits for a new control code -}) -max_length = 1 << 10 # can't go higher than 10 bits -lowmax = 1 << 5 # standard 5-bit param - -""" -If 0xff is encountered instead of a command, decompression ends. -""" -lz_end = 0xff - - -bit_flipped = [ - sum(((byte >> i) & 1) << (7 - i) for i in xrange(8)) - for byte in xrange(0x100) -] - - -class Compressed: - - """ - Usage: - lz = Compressed(data).output - or - lz = Compressed().compress(data) - or - c = Compressed() - c.data = data - lz = c.compress() - - There are some issues with reproducing the target compressor. - Some notes are listed here: - - the criteria for detecting a lookback is inconsistent - - sometimes lookbacks that are mostly 0s are pruned, sometimes not - - target appears to skip ahead if it can use a lookback soon, stopping the current command short or in some cases truncating it with literals. - - this has been implemented, but the specifics are unknown - - self.min_scores: It's unknown if blank's minimum score should be 1 or 2. Most likely it's 1, with some other hack to account for edge cases. - - may be related to the above - - target does not appear to compress backwards - """ - - def __init__(self, *args, **kwargs): - - self.min_scores = { - 'blank': 1, - 'iterate': 2, - 'alternate': 3, - 'repeat': 3, - 'reverse': 3, - 'flip': 3, - } - - self.preference = [ - 'repeat', - 'blank', - 'flip', - 'reverse', - 'iterate', - 'alternate', - #'literal', - ] - - self.lookback_methods = 'repeat', 'reverse', 'flip' - - self.__dict__.update({ - 'data': None, - 'commands': lz_commands, - 'debug': False, - 'literal_only': False, - }) - - self.arg_names = 'data', 'commands', 'debug', 'literal_only' - - self.__dict__.update(kwargs) - self.__dict__.update(dict(zip(self.arg_names, args))) - - if self.data is not None: - self.compress() - - def compress(self, data=None): - if data is not None: - self.data = data - - self.data = list(bytearray(self.data)) - - self.indexes = {} - self.lookbacks = {} - for method in self.lookback_methods: - self.lookbacks[method] = {} - - self.address = 0 - self.end = len(self.data) - self.output = [] - self.literal = None - - while self.address < self.end: - - if self.score(): - self.do_literal() - self.do_winner() - - else: - if self.literal == None: - self.literal = self.address - self.address += 1 - - self.do_literal() - - self.output += [lz_end] - return self.output - - def reset_scores(self): - self.scores = {} - self.offsets = {} - self.helpers = {} - for method in self.min_scores.iterkeys(): - self.scores[method] = 0 - - def bit_flip(self, byte): - return bit_flipped[byte] - - def do_literal(self): - if self.literal != None: - length = abs(self.address - self.literal) - start = min(self.literal, self.address + 1) - self.helpers['literal'] = self.data[start:start+length] - self.do_cmd('literal', length) - self.literal = None - - def score(self): - self.reset_scores() - - map(self.score_literal, ['iterate', 'alternate', 'blank']) - - for method in self.lookback_methods: - self.scores[method], self.offsets[method] = self.find_lookback(method, self.address) - - self.stop_short() - - return any( - score - > self.min_scores[method] + int(score > lowmax) - for method, score in self.scores.iteritems() - ) - - def stop_short(self): - """ - If a lookback is close, reduce the scores of other commands. - """ - best_method, best_score = max( - self.scores.items(), - key = lambda x: ( - x[1], - -self.preference.index(x[0]) - ) - ) - for method in self.lookback_methods: - min_score = self.min_scores[method] - for address in xrange(self.address+1, self.address+best_score): - length, index = self.find_lookback(method, address) - if length > max(min_score, best_score): - # BUG: lookbacks can reduce themselves. This appears to be a bug in the target also. - for m, score in self.scores.items(): - self.scores[m] = min(score, address - self.address) - - - def read(self, address=None): - if address is None: - address = self.address - if 0 <= address < len(self.data): - return self.data[address] - return None - - def find_all_lookbacks(self): - for method in self.lookback_methods: - for address, byte in enumerate(self.data): - self.find_lookback(method, address) - - def find_lookback(self, method, address=None): - """Temporarily stubbed, because the real function doesn't run in polynomial time.""" - return 0, None - - def broken_find_lookback(self, method, address=None): - if address is None: - address = self.address - - existing = self.lookbacks.get(method, {}).get(address) - if existing != None: - return existing - - lookback = 0, None - - # Better to not carelessly optimize at the moment. - """ - if address < 2: - return lookback - """ - - byte = self.read(address) - if byte is None: - return lookback - - direction, mutate = { - 'repeat': ( 1, int), - 'reverse': (-1, int), - 'flip': ( 1, self.bit_flip), - }[method] - - # Doesn't seem to help - """ - if mutate == self.bit_flip: - if byte == 0: - self.lookbacks[method][address] = lookback - return lookback - """ - - data_len = len(self.data) - is_two_byte_index = lambda index: int(index < address - 0x7f) - - for index in self.get_indexes(mutate(byte)): - - if index >= address: - break - - old_length, old_index = lookback - if direction == 1: - if old_length > data_len - index: break - else: - if old_length > index: continue - - if self.read(index) in [None]: continue - - length = 1 # we know there's at least one match, or we wouldn't be checking this index - while 1: - this_byte = self.read(address + length) - that_byte = self.read(index + length * direction) - if that_byte == None or this_byte != mutate(that_byte): - break - length += 1 - - score = length - is_two_byte_index(index) - old_score = old_length - is_two_byte_index(old_index) - if score >= old_score or (score == old_score and length > old_length): - # XXX maybe avoid two-byte indexes when possible - if score >= lookback[0] - is_two_byte_index(lookback[1]): - lookback = length, index - - self.lookbacks[method][address] = lookback - return lookback - - def get_indexes(self, byte): - if not self.indexes.has_key(byte): - self.indexes[byte] = [] - index = -1 - while 1: - try: - index = self.data.index(byte, index + 1) - except ValueError: - break - self.indexes[byte].append(index) - return self.indexes[byte] - - def score_literal(self, method): - address = self.address - - compare = { - 'blank': [0], - 'iterate': [self.read(address)], - 'alternate': [self.read(address), self.read(address + 1)], - }[method] - - # XXX may or may not be correct - if method == 'alternate' and compare[0] == 0: - return - - length = 0 - while self.read(address + length) == compare[length % len(compare)]: - length += 1 - - self.scores[method] = length - self.helpers[method] = compare - - def do_winner(self): - winners = filter( - lambda (method, score): - score - > self.min_scores[method] + int(score > lowmax), - self.scores.iteritems() - ) - winners.sort( - key = lambda (method, score): ( - -(score - self.min_scores[method] - int(score > lowmax)), - self.preference.index(method) - ) - ) - winner, score = winners[0] - - length = min(score, max_length) - self.do_cmd(winner, length) - self.address += length - - def do_cmd(self, cmd, length): - start_address = self.address - - cmd_length = length - 1 - - output = [] - - if length > lowmax: - output.append( - (self.commands['long'] << 5) - + (self.commands[cmd] << 2) - + (cmd_length >> 8) - ) - output.append( - cmd_length & 0xff - ) - else: - output.append( - (self.commands[cmd] << 5) - + cmd_length - ) - - self.helpers['blank'] = [] # quick hack - output += self.helpers.get(cmd, []) - - if cmd in self.lookback_methods: - offset = self.offsets[cmd] - # Negative offsets are one byte. - # Positive offsets are two. - if 0 < start_address - offset - 1 <= 0x7f: - offset = (start_address - offset - 1) | 0x80 - output += [offset] - else: - output += [offset / 0x100, offset % 0x100] # big endian - - if self.debug: - print ' '.join(map(str, [ - cmd, length, '\t', - ' '.join(map('{:02x}'.format, output)), - self.data[start_address:start_address+length] if cmd in self.lookback_methods else '', - ])) - - self.output += output - - - -class Decompressed: - """ - Interpret and decompress lz-compressed data, usually 2bpp. - """ - - """ - Usage: - data = Decompressed(lz).output - or - data = Decompressed().decompress(lz) - or - d = Decompressed() - d.lz = lz - data = d.decompress() - - To decompress from offset 0x80000 in a rom: - data = Decompressed(rom, start=0x80000).output - """ - - lz = None - start = 0 - commands = lz_commands - debug = False - - arg_names = 'lz', 'start', 'commands', 'debug' - - def __init__(self, *args, **kwargs): - self.__dict__.update(dict(zip(self.arg_names, args))) - self.__dict__.update(kwargs) - - self.command_names = dict(map(reversed, self.commands.items())) - self.address = self.start - - if self.lz is not None: - self.decompress() - - if self.debug: print self.command_list() - - - def command_list(self): - """ - Print a list of commands that were used. Useful for debugging. - """ - - text = '' - - output_address = 0 - for name, attrs in self.used_commands: - length = attrs['length'] - address = attrs['address'] - offset = attrs['offset'] - direction = attrs['direction'] - - text += '{2:03x} {0}: {1}'.format(name, length, output_address) - text += '\t' + ' '.join( - '{:02x}'.format(int(byte)) - for byte in self.lz[ address : address + attrs['cmd_length'] ] - ) - - if offset is not None: - repeated_data = self.output[ offset : offset + length * direction : direction ] - if name == 'flip': - repeated_data = map(bit_flipped.__getitem__, repeated_data) - text += ' [' + ' '.join(map('{:02x}'.format, repeated_data)) + ']' - - text += '\n' - output_address += length - - return text - - - def decompress(self, lz=None): - - if lz is not None: - self.lz = lz - - self.lz = bytearray(self.lz) - - self.used_commands = [] - self.output = [] - - while 1: - - cmd_address = self.address - self.offset = None - self.direction = None - - if (self.byte == lz_end): - self.next() - break - - self.cmd = (self.byte & 0b11100000) >> 5 - - if self.cmd_name == 'long': - # 10-bit length - self.cmd = (self.byte & 0b00011100) >> 2 - self.length = (self.next() & 0b00000011) * 0x100 - self.length += self.next() + 1 - else: - # 5-bit length - self.length = (self.next() & 0b00011111) + 1 - - self.__class__.__dict__[self.cmd_name](self) - - self.used_commands += [( - self.cmd_name, - { - 'length': self.length, - 'address': cmd_address, - 'offset': self.offset, - 'cmd_length': self.address - cmd_address, - 'direction': self.direction, - } - )] - - # Keep track of the data we just decompressed. - self.compressed_data = self.lz[self.start : self.address] - - - @property - def byte(self): - return self.lz[ self.address ] - - def next(self): - byte = self.byte - self.address += 1 - return byte - - @property - def cmd_name(self): - return self.command_names.get(self.cmd) - - - def get_offset(self): - - if self.byte >= 0x80: # negative - # negative - offset = self.next() & 0x7f - offset = len(self.output) - offset - 1 - else: - # positive - offset = self.next() * 0x100 - offset += self.next() - - self.offset = offset - - - def literal(self): - """ - Copy data directly. - """ - self.output += self.lz[ self.address : self.address + self.length ] - self.address += self.length - - def iterate(self): - """ - Write one byte repeatedly. - """ - self.output += [self.next()] * self.length - - def alternate(self): - """ - Write alternating bytes. - """ - alts = [self.next(), self.next()] - self.output += [ alts[x & 1] for x in xrange(self.length) ] - - def blank(self): - """ - Write zeros. - """ - self.output += [0] * self.length - - def flip(self): - """ - Repeat flipped bytes from output. - - Example: 11100100 -> 00100111 - """ - self._repeat(table=bit_flipped) - - def reverse(self): - """ - Repeat reversed bytes from output. - """ - self._repeat(direction=-1) - - def repeat(self): - """ - Repeat bytes from output. - """ - self._repeat() - - def _repeat(self, direction=1, table=None): - self.get_offset() - self.direction = direction - # Note: appends must be one at a time (this way, repeats can draw from themselves if required) - for i in xrange(self.length): - byte = self.output[ self.offset + i * direction ] - self.output.append( table[byte] if table else byte ) diff --git a/tools/pokemontools/png.py b/tools/pokemontools/png.py deleted file mode 100644 index db6da1287..000000000 --- a/tools/pokemontools/png.py +++ /dev/null @@ -1,2650 +0,0 @@ -#!/usr/bin/env python - -from __future__ import print_function - -# png.py - PNG encoder/decoder in pure Python -# -# Copyright (C) 2006 Johann C. Rocholl -# Portions Copyright (C) 2009 David Jones -# And probably portions Copyright (C) 2006 Nicko van Someren -# -# Original concept by Johann C. Rocholl. -# -# LICENCE (MIT) -# -# Permission is hereby granted, free of charge, to any person -# obtaining a copy of this software and associated documentation files -# (the "Software"), to deal in the Software without restriction, -# including without limitation the rights to use, copy, modify, merge, -# publish, distribute, sublicense, and/or sell copies of the Software, -# and to permit persons to whom the Software is furnished to do so, -# subject to the following conditions: -# -# The above copyright notice and this permission notice shall be -# included in all copies or substantial portions of the Software. -# -# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, -# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF -# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND -# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS -# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN -# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN -# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE -# SOFTWARE. - -""" -Pure Python PNG Reader/Writer - -This Python module implements support for PNG images (see PNG -specification at http://www.w3.org/TR/2003/REC-PNG-20031110/ ). It reads -and writes PNG files with all allowable bit depths -(1/2/4/8/16/24/32/48/64 bits per pixel) and colour combinations: -greyscale (1/2/4/8/16 bit); RGB, RGBA, LA (greyscale with alpha) with -8/16 bits per channel; colour mapped images (1/2/4/8 bit). -Adam7 interlacing is supported for reading and -writing. A number of optional chunks can be specified (when writing) -and understood (when reading): ``tRNS``, ``bKGD``, ``gAMA``. - -For help, type ``import png; help(png)`` in your python interpreter. - -A good place to start is the :class:`Reader` and :class:`Writer` -classes. - -Requires Python 2.3. Limited support is available for Python 2.2, but -not everything works. Best with Python 2.4 and higher. Installation is -trivial, but see the ``README.txt`` file (with the source distribution) -for details. - -This file can also be used as a command-line utility to convert -`Netpbm `_ PNM files to PNG, and the -reverse conversion from PNG to PNM. The interface is similar to that -of the ``pnmtopng`` program from Netpbm. Type ``python png.py --help`` -at the shell prompt for usage and a list of options. - -A note on spelling and terminology ----------------------------------- - -Generally British English spelling is used in the documentation. So -that's "greyscale" and "colour". This not only matches the author's -native language, it's also used by the PNG specification. - -The major colour models supported by PNG (and hence by PyPNG) are: -greyscale, RGB, greyscale--alpha, RGB--alpha. These are sometimes -referred to using the abbreviations: L, RGB, LA, RGBA. In this case -each letter abbreviates a single channel: *L* is for Luminance or Luma -or Lightness which is the channel used in greyscale images; *R*, *G*, -*B* stand for Red, Green, Blue, the components of a colour image; *A* -stands for Alpha, the opacity channel (used for transparency effects, -but higher values are more opaque, so it makes sense to call it -opacity). - -A note on formats ------------------ - -When getting pixel data out of this module (reading) and presenting -data to this module (writing) there are a number of ways the data could -be represented as a Python value. Generally this module uses one of -three formats called "flat row flat pixel", "boxed row flat pixel", and -"boxed row boxed pixel". Basically the concern is whether each pixel -and each row comes in its own little tuple (box), or not. - -Consider an image that is 3 pixels wide by 2 pixels high, and each pixel -has RGB components: - -Boxed row flat pixel:: - - list([R,G,B, R,G,B, R,G,B], - [R,G,B, R,G,B, R,G,B]) - -Each row appears as its own list, but the pixels are flattened so -that three values for one pixel simply follow the three values for -the previous pixel. This is the most common format used, because it -provides a good compromise between space and convenience. PyPNG regards -itself as at liberty to replace any sequence type with any sufficiently -compatible other sequence type; in practice each row is an array (from -the array module), and the outer list is sometimes an iterator rather -than an explicit list (so that streaming is possible). - -Flat row flat pixel:: - - [R,G,B, R,G,B, R,G,B, - R,G,B, R,G,B, R,G,B] - -The entire image is one single giant sequence of colour values. -Generally an array will be used (to save space), not a list. - -Boxed row boxed pixel:: - - list([ (R,G,B), (R,G,B), (R,G,B) ], - [ (R,G,B), (R,G,B), (R,G,B) ]) - -Each row appears in its own list, but each pixel also appears in its own -tuple. A serious memory burn in Python. - -In all cases the top row comes first, and for each row the pixels are -ordered from left-to-right. Within a pixel the values appear in the -order, R-G-B-A (or L-A for greyscale--alpha). - -There is a fourth format, mentioned because it is used internally, -is close to what lies inside a PNG file itself, and has some support -from the public API. This format is called packed. When packed, -each row is a sequence of bytes (integers from 0 to 255), just as -it is before PNG scanline filtering is applied. When the bit depth -is 8 this is essentially the same as boxed row flat pixel; when the -bit depth is less than 8, several pixels are packed into each byte; -when the bit depth is 16 (the only value more than 8 that is supported -by the PNG image format) each pixel value is decomposed into 2 bytes -(and `packed` is a misnomer). This format is used by the -:meth:`Writer.write_packed` method. It isn't usually a convenient -format, but may be just right if the source data for the PNG image -comes from something that uses a similar format (for example, 1-bit -BMPs, or another PNG file). - -And now, my famous members --------------------------- -""" - -__version__ = "0.0.18" - -import itertools -import math -# http://www.python.org/doc/2.4.4/lib/module-operator.html -import operator -import struct -import sys -# http://www.python.org/doc/2.4.4/lib/module-warnings.html -import warnings -import zlib - -from array import array -from functools import reduce - -try: - # `cpngfilters` is a Cython module: it must be compiled by - # Cython for this import to work. - # If this import does work, then it overrides pure-python - # filtering functions defined later in this file (see `class - # pngfilters`). - import cpngfilters as pngfilters -except ImportError: - pass - - -__all__ = ['Image', 'Reader', 'Writer', 'write_chunks', 'from_array'] - - -# The PNG signature. -# http://www.w3.org/TR/PNG/#5PNG-file-signature -_signature = struct.pack('8B', 137, 80, 78, 71, 13, 10, 26, 10) - -_adam7 = ((0, 0, 8, 8), - (4, 0, 8, 8), - (0, 4, 4, 8), - (2, 0, 4, 4), - (0, 2, 2, 4), - (1, 0, 2, 2), - (0, 1, 1, 2)) - -def group(s, n): - # See http://www.python.org/doc/2.6/library/functions.html#zip - return list(zip(*[iter(s)]*n)) - -def isarray(x): - return isinstance(x, array) - -def tostring(row): - return row.tostring() - -def interleave_planes(ipixels, apixels, ipsize, apsize): - """ - Interleave (colour) planes, e.g. RGB + A = RGBA. - - Return an array of pixels consisting of the `ipsize` elements of - data from each pixel in `ipixels` followed by the `apsize` elements - of data from each pixel in `apixels`. Conventionally `ipixels` - and `apixels` are byte arrays so the sizes are bytes, but it - actually works with any arrays of the same type. The returned - array is the same type as the input arrays which should be the - same type as each other. - """ - - itotal = len(ipixels) - atotal = len(apixels) - newtotal = itotal + atotal - newpsize = ipsize + apsize - # Set up the output buffer - # See http://www.python.org/doc/2.4.4/lib/module-array.html#l2h-1356 - out = array(ipixels.typecode) - # It's annoying that there is no cheap way to set the array size :-( - out.extend(ipixels) - out.extend(apixels) - # Interleave in the pixel data - for i in range(ipsize): - out[i:newtotal:newpsize] = ipixels[i:itotal:ipsize] - for i in range(apsize): - out[i+ipsize:newtotal:newpsize] = apixels[i:atotal:apsize] - return out - -def check_palette(palette): - """Check a palette argument (to the :class:`Writer` class) - for validity. Returns the palette as a list if okay; raises an - exception otherwise. - """ - - # None is the default and is allowed. - if palette is None: - return None - - p = list(palette) - if not (0 < len(p) <= 256): - raise ValueError("a palette must have between 1 and 256 entries") - seen_triple = False - for i,t in enumerate(p): - if len(t) not in (3,4): - raise ValueError( - "palette entry %d: entries must be 3- or 4-tuples." % i) - if len(t) == 3: - seen_triple = True - if seen_triple and len(t) == 4: - raise ValueError( - "palette entry %d: all 4-tuples must precede all 3-tuples" % i) - for x in t: - if int(x) != x or not(0 <= x <= 255): - raise ValueError( - "palette entry %d: values must be integer: 0 <= x <= 255" % i) - return p - -def check_sizes(size, width, height): - """Check that these arguments, in supplied, are consistent. - Return a (width, height) pair. - """ - - if not size: - return width, height - - if len(size) != 2: - raise ValueError( - "size argument should be a pair (width, height)") - if width is not None and width != size[0]: - raise ValueError( - "size[0] (%r) and width (%r) should match when both are used." - % (size[0], width)) - if height is not None and height != size[1]: - raise ValueError( - "size[1] (%r) and height (%r) should match when both are used." - % (size[1], height)) - return size - -def check_color(c, greyscale, which): - """Checks that a colour argument for transparent or - background options is the right form. Returns the colour - (which, if it's a bar integer, is "corrected" to a 1-tuple). - """ - - if c is None: - return c - if greyscale: - try: - len(c) - except TypeError: - c = (c,) - if len(c) != 1: - raise ValueError("%s for greyscale must be 1-tuple" % - which) - if not isinteger(c[0]): - raise ValueError( - "%s colour for greyscale must be integer" % which) - else: - if not (len(c) == 3 and - isinteger(c[0]) and - isinteger(c[1]) and - isinteger(c[2])): - raise ValueError( - "%s colour must be a triple of integers" % which) - return c - -class Error(Exception): - def __str__(self): - return self.__class__.__name__ + ': ' + ' '.join(self.args) - -class FormatError(Error): - """Problem with input file format. In other words, PNG file does - not conform to the specification in some way and is invalid. - """ - -class ChunkError(FormatError): - pass - - -class Writer: - """ - PNG encoder in pure Python. - """ - - def __init__(self, width=None, height=None, - size=None, - greyscale=False, - alpha=False, - bitdepth=8, - palette=None, - transparent=None, - background=None, - gamma=None, - compression=None, - interlace=False, - bytes_per_sample=None, # deprecated - planes=None, - colormap=None, - maxval=None, - chunk_limit=2**20, - x_pixels_per_unit = None, - y_pixels_per_unit = None, - unit_is_meter = False): - """ - Create a PNG encoder object. - - Arguments: - - width, height - Image size in pixels, as two separate arguments. - size - Image size (w,h) in pixels, as single argument. - greyscale - Input data is greyscale, not RGB. - alpha - Input data has alpha channel (RGBA or LA). - bitdepth - Bit depth: from 1 to 16. - palette - Create a palette for a colour mapped image (colour type 3). - transparent - Specify a transparent colour (create a ``tRNS`` chunk). - background - Specify a default background colour (create a ``bKGD`` chunk). - gamma - Specify a gamma value (create a ``gAMA`` chunk). - compression - zlib compression level: 0 (none) to 9 (more compressed); - default: -1 or None. - interlace - Create an interlaced image. - chunk_limit - Write multiple ``IDAT`` chunks to save memory. - x_pixels_per_unit - Number of pixels a unit along the x axis (write a - `pHYs` chunk). - y_pixels_per_unit - Number of pixels a unit along the y axis (write a - `pHYs` chunk). Along with `x_pixel_unit`, this gives - the pixel size ratio. - unit_is_meter - `True` to indicate that the unit (for the `pHYs` - chunk) is metre. - - The image size (in pixels) can be specified either by using the - `width` and `height` arguments, or with the single `size` - argument. If `size` is used it should be a pair (*width*, - *height*). - - `greyscale` and `alpha` are booleans that specify whether - an image is greyscale (or colour), and whether it has an - alpha channel (or not). - - `bitdepth` specifies the bit depth of the source pixel values. - Each source pixel value must be an integer between 0 and - ``2**bitdepth-1``. For example, 8-bit images have values - between 0 and 255. PNG only stores images with bit depths of - 1,2,4,8, or 16. When `bitdepth` is not one of these values, - the next highest valid bit depth is selected, and an ``sBIT`` - (significant bits) chunk is generated that specifies the - original precision of the source image. In this case the - supplied pixel values will be rescaled to fit the range of - the selected bit depth. - - The details of which bit depth / colour model combinations the - PNG file format supports directly, are somewhat arcane - (refer to the PNG specification for full details). Briefly: - "small" bit depths (1,2,4) are only allowed with greyscale and - colour mapped images; colour mapped images cannot have bit depth - 16. - - For colour mapped images (in other words, when the `palette` - argument is specified) the `bitdepth` argument must match one of - the valid PNG bit depths: 1, 2, 4, or 8. (It is valid to have a - PNG image with a palette and an ``sBIT`` chunk, but the meaning - is slightly different; it would be awkward to press the - `bitdepth` argument into service for this.) - - The `palette` option, when specified, causes a colour - mapped image to be created: the PNG colour type is set to 3; - `greyscale` must not be set; `alpha` must not be set; - `transparent` must not be set; the bit depth must be 1,2,4, - or 8. When a colour mapped image is created, the pixel values - are palette indexes and the `bitdepth` argument specifies the - size of these indexes (not the size of the colour values in - the palette). - - The palette argument value should be a sequence of 3- or - 4-tuples. 3-tuples specify RGB palette entries; 4-tuples - specify RGBA palette entries. If both 4-tuples and 3-tuples - appear in the sequence then all the 4-tuples must come - before all the 3-tuples. A ``PLTE`` chunk is created; if there - are 4-tuples then a ``tRNS`` chunk is created as well. The - ``PLTE`` chunk will contain all the RGB triples in the same - sequence; the ``tRNS`` chunk will contain the alpha channel for - all the 4-tuples, in the same sequence. Palette entries - are always 8-bit. - - If specified, the `transparent` and `background` parameters must - be a tuple with three integer values for red, green, blue, or - a simple integer (or singleton tuple) for a greyscale image. - - If specified, the `gamma` parameter must be a positive number - (generally, a `float`). A ``gAMA`` chunk will be created. - Note that this will not change the values of the pixels as - they appear in the PNG file, they are assumed to have already - been converted appropriately for the gamma specified. - - The `compression` argument specifies the compression level to - be used by the ``zlib`` module. Values from 1 to 9 specify - compression, with 9 being "more compressed" (usually smaller - and slower, but it doesn't always work out that way). 0 means - no compression. -1 and ``None`` both mean that the default - level of compession will be picked by the ``zlib`` module - (which is generally acceptable). - - If `interlace` is true then an interlaced image is created - (using PNG's so far only interace method, *Adam7*). This does - not affect how the pixels should be presented to the encoder, - rather it changes how they are arranged into the PNG file. - On slow connexions interlaced images can be partially decoded - by the browser to give a rough view of the image that is - successively refined as more image data appears. - - .. note :: - - Enabling the `interlace` option requires the entire image - to be processed in working memory. - - `chunk_limit` is used to limit the amount of memory used whilst - compressing the image. In order to avoid using large amounts of - memory, multiple ``IDAT`` chunks may be created. - """ - - # At the moment the `planes` argument is ignored; - # its purpose is to act as a dummy so that - # ``Writer(x, y, **info)`` works, where `info` is a dictionary - # returned by Reader.read and friends. - # Ditto for `colormap`. - - width, height = check_sizes(size, width, height) - del size - - if width <= 0 or height <= 0: - raise ValueError("width and height must be greater than zero") - if not isinteger(width) or not isinteger(height): - raise ValueError("width and height must be integers") - # http://www.w3.org/TR/PNG/#7Integers-and-byte-order - if width > 2**32-1 or height > 2**32-1: - raise ValueError("width and height cannot exceed 2**32-1") - - if alpha and transparent is not None: - raise ValueError( - "transparent colour not allowed with alpha channel") - - if bytes_per_sample is not None: - warnings.warn('please use bitdepth instead of bytes_per_sample', - DeprecationWarning) - if bytes_per_sample not in (0.125, 0.25, 0.5, 1, 2): - raise ValueError( - "bytes per sample must be .125, .25, .5, 1, or 2") - bitdepth = int(8*bytes_per_sample) - del bytes_per_sample - if not isinteger(bitdepth) or bitdepth < 1 or 16 < bitdepth: - raise ValueError("bitdepth (%r) must be a positive integer <= 16" % - bitdepth) - - self.rescale = None - palette = check_palette(palette) - if palette: - if bitdepth not in (1,2,4,8): - raise ValueError("with palette, bitdepth must be 1, 2, 4, or 8") - if transparent is not None: - raise ValueError("transparent and palette not compatible") - if alpha: - raise ValueError("alpha and palette not compatible") - if greyscale: - raise ValueError("greyscale and palette not compatible") - else: - # No palette, check for sBIT chunk generation. - if alpha or not greyscale: - if bitdepth not in (8,16): - targetbitdepth = (8,16)[bitdepth > 8] - self.rescale = (bitdepth, targetbitdepth) - bitdepth = targetbitdepth - del targetbitdepth - else: - assert greyscale - assert not alpha - if bitdepth not in (1,2,4,8,16): - if bitdepth > 8: - targetbitdepth = 16 - elif bitdepth == 3: - targetbitdepth = 4 - else: - assert bitdepth in (5,6,7) - targetbitdepth = 8 - self.rescale = (bitdepth, targetbitdepth) - bitdepth = targetbitdepth - del targetbitdepth - - if bitdepth < 8 and (alpha or not greyscale and not palette): - raise ValueError( - "bitdepth < 8 only permitted with greyscale or palette") - if bitdepth > 8 and palette: - raise ValueError( - "bit depth must be 8 or less for images with palette") - - transparent = check_color(transparent, greyscale, 'transparent') - background = check_color(background, greyscale, 'background') - - # It's important that the true boolean values (greyscale, alpha, - # colormap, interlace) are converted to bool because Iverson's - # convention is relied upon later on. - self.width = width - self.height = height - self.transparent = transparent - self.background = background - self.gamma = gamma - self.greyscale = bool(greyscale) - self.alpha = bool(alpha) - self.colormap = bool(palette) - self.bitdepth = int(bitdepth) - self.compression = compression - self.chunk_limit = chunk_limit - self.interlace = bool(interlace) - self.palette = palette - self.x_pixels_per_unit = x_pixels_per_unit - self.y_pixels_per_unit = y_pixels_per_unit - self.unit_is_meter = bool(unit_is_meter) - - self.color_type = 4*self.alpha + 2*(not greyscale) + 1*self.colormap - assert self.color_type in (0,2,3,4,6) - - self.color_planes = (3,1)[self.greyscale or self.colormap] - self.planes = self.color_planes + self.alpha - # :todo: fix for bitdepth < 8 - self.psize = (self.bitdepth/8) * self.planes - - def make_palette(self): - """Create the byte sequences for a ``PLTE`` and if necessary a - ``tRNS`` chunk. Returned as a pair (*p*, *t*). *t* will be - ``None`` if no ``tRNS`` chunk is necessary. - """ - - p = array('B') - t = array('B') - - for x in self.palette: - p.extend(x[0:3]) - if len(x) > 3: - t.append(x[3]) - p = tostring(p) - t = tostring(t) - if t: - return p,t - return p,None - - def write(self, outfile, rows): - """Write a PNG image to the output file. `rows` should be - an iterable that yields each row in boxed row flat pixel - format. The rows should be the rows of the original image, - so there should be ``self.height`` rows of ``self.width * - self.planes`` values. If `interlace` is specified (when - creating the instance), then an interlaced PNG file will - be written. Supply the rows in the normal image order; - the interlacing is carried out internally. - - .. note :: - - Interlacing will require the entire image to be in working - memory. - """ - - if self.interlace: - fmt = 'BH'[self.bitdepth > 8] - a = array(fmt, itertools.chain(*rows)) - return self.write_array(outfile, a) - - nrows = self.write_passes(outfile, rows) - if nrows != self.height: - raise ValueError( - "rows supplied (%d) does not match height (%d)" % - (nrows, self.height)) - - def write_passes(self, outfile, rows, packed=False): - """ - Write a PNG image to the output file. - - Most users are expected to find the :meth:`write` or - :meth:`write_array` method more convenient. - - The rows should be given to this method in the order that - they appear in the output file. For straightlaced images, - this is the usual top to bottom ordering, but for interlaced - images the rows should have already been interlaced before - passing them to this function. - - `rows` should be an iterable that yields each row. When - `packed` is ``False`` the rows should be in boxed row flat pixel - format; when `packed` is ``True`` each row should be a packed - sequence of bytes. - """ - - # http://www.w3.org/TR/PNG/#5PNG-file-signature - outfile.write(_signature) - - # http://www.w3.org/TR/PNG/#11IHDR - write_chunk(outfile, b'IHDR', - struct.pack("!2I5B", self.width, self.height, - self.bitdepth, self.color_type, - 0, 0, self.interlace)) - - # See :chunk:order - # http://www.w3.org/TR/PNG/#11gAMA - if self.gamma is not None: - write_chunk(outfile, b'gAMA', - struct.pack("!L", int(round(self.gamma*1e5)))) - - # See :chunk:order - # http://www.w3.org/TR/PNG/#11sBIT - if self.rescale: - write_chunk(outfile, b'sBIT', - struct.pack('%dB' % self.planes, - *[self.rescale[0]]*self.planes)) - - # :chunk:order: Without a palette (PLTE chunk), ordering is - # relatively relaxed. With one, gAMA chunk must precede PLTE - # chunk which must precede tRNS and bKGD. - # See http://www.w3.org/TR/PNG/#5ChunkOrdering - if self.palette: - p,t = self.make_palette() - write_chunk(outfile, b'PLTE', p) - if t: - # tRNS chunk is optional. Only needed if palette entries - # have alpha. - write_chunk(outfile, b'tRNS', t) - - # http://www.w3.org/TR/PNG/#11tRNS - if self.transparent is not None: - if self.greyscale: - write_chunk(outfile, b'tRNS', - struct.pack("!1H", *self.transparent)) - else: - write_chunk(outfile, b'tRNS', - struct.pack("!3H", *self.transparent)) - - # http://www.w3.org/TR/PNG/#11bKGD - if self.background is not None: - if self.greyscale: - write_chunk(outfile, b'bKGD', - struct.pack("!1H", *self.background)) - else: - write_chunk(outfile, b'bKGD', - struct.pack("!3H", *self.background)) - - # http://www.w3.org/TR/PNG/#11pHYs - if self.x_pixels_per_unit is not None and self.y_pixels_per_unit is not None: - tup = (self.x_pixels_per_unit, self.y_pixels_per_unit, int(self.unit_is_meter)) - write_chunk(outfile, b'pHYs', struct.pack("!LLB",*tup)) - - # http://www.w3.org/TR/PNG/#11IDAT - if self.compression is not None: - compressor = zlib.compressobj(self.compression) - else: - compressor = zlib.compressobj() - - # Choose an extend function based on the bitdepth. The extend - # function packs/decomposes the pixel values into bytes and - # stuffs them onto the data array. - data = array('B') - if self.bitdepth == 8 or packed: - extend = data.extend - elif self.bitdepth == 16: - # Decompose into bytes - def extend(sl): - fmt = '!%dH' % len(sl) - data.extend(array('B', struct.pack(fmt, *sl))) - else: - # Pack into bytes - assert self.bitdepth < 8 - # samples per byte - spb = int(8/self.bitdepth) - def extend(sl): - a = array('B', sl) - # Adding padding bytes so we can group into a whole - # number of spb-tuples. - l = float(len(a)) - extra = math.ceil(l / float(spb))*spb - l - a.extend([0]*int(extra)) - # Pack into bytes - l = group(a, spb) - l = [reduce(lambda x,y: - (x << self.bitdepth) + y, e) for e in l] - data.extend(l) - if self.rescale: - oldextend = extend - factor = \ - float(2**self.rescale[1]-1) / float(2**self.rescale[0]-1) - def extend(sl): - oldextend([int(round(factor*x)) for x in sl]) - - # Build the first row, testing mostly to see if we need to - # changed the extend function to cope with NumPy integer types - # (they cause our ordinary definition of extend to fail, so we - # wrap it). See - # http://code.google.com/p/pypng/issues/detail?id=44 - enumrows = enumerate(rows) - del rows - - # First row's filter type. - data.append(0) - # :todo: Certain exceptions in the call to ``.next()`` or the - # following try would indicate no row data supplied. - # Should catch. - i,row = next(enumrows) - try: - # If this fails... - extend(row) - except: - # ... try a version that converts the values to int first. - # Not only does this work for the (slightly broken) NumPy - # types, there are probably lots of other, unknown, "nearly" - # int types it works for. - def wrapmapint(f): - return lambda sl: f([int(x) for x in sl]) - extend = wrapmapint(extend) - del wrapmapint - extend(row) - - for i,row in enumrows: - # Add "None" filter type. Currently, it's essential that - # this filter type be used for every scanline as we do not - # mark the first row of a reduced pass image; that means we - # could accidentally compute the wrong filtered scanline if - # we used "up", "average", or "paeth" on such a line. - data.append(0) - extend(row) - if len(data) > self.chunk_limit: - compressed = compressor.compress(tostring(data)) - if len(compressed): - write_chunk(outfile, b'IDAT', compressed) - # Because of our very witty definition of ``extend``, - # above, we must re-use the same ``data`` object. Hence - # we use ``del`` to empty this one, rather than create a - # fresh one (which would be my natural FP instinct). - del data[:] - if len(data): - compressed = compressor.compress(tostring(data)) - else: - compressed = b'' - flushed = compressor.flush() - if len(compressed) or len(flushed): - write_chunk(outfile, b'IDAT', compressed + flushed) - # http://www.w3.org/TR/PNG/#11IEND - write_chunk(outfile, b'IEND') - return i+1 - - def write_array(self, outfile, pixels): - """ - Write an array in flat row flat pixel format as a PNG file on - the output file. See also :meth:`write` method. - """ - - if self.interlace: - self.write_passes(outfile, self.array_scanlines_interlace(pixels)) - else: - self.write_passes(outfile, self.array_scanlines(pixels)) - - def write_packed(self, outfile, rows): - """ - Write PNG file to `outfile`. The pixel data comes from `rows` - which should be in boxed row packed format. Each row should be - a sequence of packed bytes. - - Technically, this method does work for interlaced images but it - is best avoided. For interlaced images, the rows should be - presented in the order that they appear in the file. - - This method should not be used when the source image bit depth - is not one naturally supported by PNG; the bit depth should be - 1, 2, 4, 8, or 16. - """ - - if self.rescale: - raise Error("write_packed method not suitable for bit depth %d" % - self.rescale[0]) - return self.write_passes(outfile, rows, packed=True) - - def convert_pnm(self, infile, outfile): - """ - Convert a PNM file containing raw pixel data into a PNG file - with the parameters set in the writer object. Works for - (binary) PGM, PPM, and PAM formats. - """ - - if self.interlace: - pixels = array('B') - pixels.fromfile(infile, - (self.bitdepth/8) * self.color_planes * - self.width * self.height) - self.write_passes(outfile, self.array_scanlines_interlace(pixels)) - else: - self.write_passes(outfile, self.file_scanlines(infile)) - - def convert_ppm_and_pgm(self, ppmfile, pgmfile, outfile): - """ - Convert a PPM and PGM file containing raw pixel data into a - PNG outfile with the parameters set in the writer object. - """ - pixels = array('B') - pixels.fromfile(ppmfile, - (self.bitdepth/8) * self.color_planes * - self.width * self.height) - apixels = array('B') - apixels.fromfile(pgmfile, - (self.bitdepth/8) * - self.width * self.height) - pixels = interleave_planes(pixels, apixels, - (self.bitdepth/8) * self.color_planes, - (self.bitdepth/8)) - if self.interlace: - self.write_passes(outfile, self.array_scanlines_interlace(pixels)) - else: - self.write_passes(outfile, self.array_scanlines(pixels)) - - def file_scanlines(self, infile): - """ - Generates boxed rows in flat pixel format, from the input file - `infile`. It assumes that the input file is in a "Netpbm-like" - binary format, and is positioned at the beginning of the first - pixel. The number of pixels to read is taken from the image - dimensions (`width`, `height`, `planes`) and the number of bytes - per value is implied by the image `bitdepth`. - """ - - # Values per row - vpr = self.width * self.planes - row_bytes = vpr - if self.bitdepth > 8: - assert self.bitdepth == 16 - row_bytes *= 2 - fmt = '>%dH' % vpr - def line(): - return array('H', struct.unpack(fmt, infile.read(row_bytes))) - else: - def line(): - scanline = array('B', infile.read(row_bytes)) - return scanline - for y in range(self.height): - yield line() - - def array_scanlines(self, pixels): - """ - Generates boxed rows (flat pixels) from flat rows (flat pixels) - in an array. - """ - - # Values per row - vpr = self.width * self.planes - stop = 0 - for y in range(self.height): - start = stop - stop = start + vpr - yield pixels[start:stop] - - def array_scanlines_interlace(self, pixels): - """ - Generator for interlaced scanlines from an array. `pixels` is - the full source image in flat row flat pixel format. The - generator yields each scanline of the reduced passes in turn, in - boxed row flat pixel format. - """ - - # http://www.w3.org/TR/PNG/#8InterlaceMethods - # Array type. - fmt = 'BH'[self.bitdepth > 8] - # Value per row - vpr = self.width * self.planes - for xstart, ystart, xstep, ystep in _adam7: - if xstart >= self.width: - continue - # Pixels per row (of reduced image) - ppr = int(math.ceil((self.width-xstart)/float(xstep))) - # number of values in reduced image row. - row_len = ppr*self.planes - for y in range(ystart, self.height, ystep): - if xstep == 1: - offset = y * vpr - yield pixels[offset:offset+vpr] - else: - row = array(fmt) - # There's no easier way to set the length of an array - row.extend(pixels[0:row_len]) - offset = y * vpr + xstart * self.planes - end_offset = (y+1) * vpr - skip = self.planes * xstep - for i in range(self.planes): - row[i::self.planes] = \ - pixels[offset+i:end_offset:skip] - yield row - -def write_chunk(outfile, tag, data=b''): - """ - Write a PNG chunk to the output file, including length and - checksum. - """ - - # http://www.w3.org/TR/PNG/#5Chunk-layout - outfile.write(struct.pack("!I", len(data))) - outfile.write(tag) - outfile.write(data) - checksum = zlib.crc32(tag) - checksum = zlib.crc32(data, checksum) - checksum &= 2**32-1 - outfile.write(struct.pack("!I", checksum)) - -def write_chunks(out, chunks): - """Create a PNG file by writing out the chunks.""" - - out.write(_signature) - for chunk in chunks: - write_chunk(out, *chunk) - -def filter_scanline(type, line, fo, prev=None): - """Apply a scanline filter to a scanline. `type` specifies the - filter type (0 to 4); `line` specifies the current (unfiltered) - scanline as a sequence of bytes; `prev` specifies the previous - (unfiltered) scanline as a sequence of bytes. `fo` specifies the - filter offset; normally this is size of a pixel in bytes (the number - of bytes per sample times the number of channels), but when this is - < 1 (for bit depths < 8) then the filter offset is 1. - """ - - assert 0 <= type < 5 - - # The output array. Which, pathetically, we extend one-byte at a - # time (fortunately this is linear). - out = array('B', [type]) - - def sub(): - ai = -fo - for x in line: - if ai >= 0: - x = (x - line[ai]) & 0xff - out.append(x) - ai += 1 - def up(): - for i,x in enumerate(line): - x = (x - prev[i]) & 0xff - out.append(x) - def average(): - ai = -fo - for i,x in enumerate(line): - if ai >= 0: - x = (x - ((line[ai] + prev[i]) >> 1)) & 0xff - else: - x = (x - (prev[i] >> 1)) & 0xff - out.append(x) - ai += 1 - def paeth(): - # http://www.w3.org/TR/PNG/#9Filter-type-4-Paeth - ai = -fo # also used for ci - for i,x in enumerate(line): - a = 0 - b = prev[i] - c = 0 - - if ai >= 0: - a = line[ai] - c = prev[ai] - p = a + b - c - pa = abs(p - a) - pb = abs(p - b) - pc = abs(p - c) - if pa <= pb and pa <= pc: - Pr = a - elif pb <= pc: - Pr = b - else: - Pr = c - - x = (x - Pr) & 0xff - out.append(x) - ai += 1 - - if not prev: - # We're on the first line. Some of the filters can be reduced - # to simpler cases which makes handling the line "off the top" - # of the image simpler. "up" becomes "none"; "paeth" becomes - # "left" (non-trivial, but true). "average" needs to be handled - # specially. - if type == 2: # "up" - type = 0 - elif type == 3: - prev = [0]*len(line) - elif type == 4: # "paeth" - type = 1 - if type == 0: - out.extend(line) - elif type == 1: - sub() - elif type == 2: - up() - elif type == 3: - average() - else: # type == 4 - paeth() - return out - - -def from_array(a, mode=None, info={}): - """Create a PNG :class:`Image` object from a 2- or 3-dimensional - array. One application of this function is easy PIL-style saving: - ``png.from_array(pixels, 'L').save('foo.png')``. - - Unless they are specified using the *info* parameter, the PNG's - height and width are taken from the array size. For a 3 dimensional - array the first axis is the height; the second axis is the width; - and the third axis is the channel number. Thus an RGB image that is - 16 pixels high and 8 wide will use an array that is 16x8x3. For 2 - dimensional arrays the first axis is the height, but the second axis - is ``width*channels``, so an RGB image that is 16 pixels high and 8 - wide will use a 2-dimensional array that is 16x24 (each row will be - 8*3 = 24 sample values). - - *mode* is a string that specifies the image colour format in a - PIL-style mode. It can be: - - ``'L'`` - greyscale (1 channel) - ``'LA'`` - greyscale with alpha (2 channel) - ``'RGB'`` - colour image (3 channel) - ``'RGBA'`` - colour image with alpha (4 channel) - - The mode string can also specify the bit depth (overriding how this - function normally derives the bit depth, see below). Appending - ``';16'`` to the mode will cause the PNG to be 16 bits per channel; - any decimal from 1 to 16 can be used to specify the bit depth. - - When a 2-dimensional array is used *mode* determines how many - channels the image has, and so allows the width to be derived from - the second array dimension. - - The array is expected to be a ``numpy`` array, but it can be any - suitable Python sequence. For example, a list of lists can be used: - ``png.from_array([[0, 255, 0], [255, 0, 255]], 'L')``. The exact - rules are: ``len(a)`` gives the first dimension, height; - ``len(a[0])`` gives the second dimension; ``len(a[0][0])`` gives the - third dimension, unless an exception is raised in which case a - 2-dimensional array is assumed. It's slightly more complicated than - that because an iterator of rows can be used, and it all still - works. Using an iterator allows data to be streamed efficiently. - - The bit depth of the PNG is normally taken from the array element's - datatype (but if *mode* specifies a bitdepth then that is used - instead). The array element's datatype is determined in a way which - is supposed to work both for ``numpy`` arrays and for Python - ``array.array`` objects. A 1 byte datatype will give a bit depth of - 8, a 2 byte datatype will give a bit depth of 16. If the datatype - does not have an implicit size, for example it is a plain Python - list of lists, as above, then a default of 8 is used. - - The *info* parameter is a dictionary that can be used to specify - metadata (in the same style as the arguments to the - :class:`png.Writer` class). For this function the keys that are - useful are: - - height - overrides the height derived from the array dimensions and allows - *a* to be an iterable. - width - overrides the width derived from the array dimensions. - bitdepth - overrides the bit depth derived from the element datatype (but - must match *mode* if that also specifies a bit depth). - - Generally anything specified in the - *info* dictionary will override any implicit choices that this - function would otherwise make, but must match any explicit ones. - For example, if the *info* dictionary has a ``greyscale`` key then - this must be true when mode is ``'L'`` or ``'LA'`` and false when - mode is ``'RGB'`` or ``'RGBA'``. - """ - - # We abuse the *info* parameter by modifying it. Take a copy here. - # (Also typechecks *info* to some extent). - info = dict(info) - - # Syntax check mode string. - bitdepth = None - try: - # Assign the 'L' or 'RGBA' part to `gotmode`. - if mode.startswith('L'): - gotmode = 'L' - mode = mode[1:] - elif mode.startswith('RGB'): - gotmode = 'RGB' - mode = mode[3:] - else: - raise Error() - if mode.startswith('A'): - gotmode += 'A' - mode = mode[1:] - - # Skip any optional ';' - while mode.startswith(';'): - mode = mode[1:] - - # Parse optional bitdepth - if mode: - try: - bitdepth = int(mode) - except (TypeError, ValueError): - raise Error() - except Error: - raise Error("mode string should be 'RGB' or 'L;16' or similar.") - mode = gotmode - - # Get bitdepth from *mode* if possible. - if bitdepth: - if info.get('bitdepth') and bitdepth != info['bitdepth']: - raise Error("mode bitdepth (%d) should match info bitdepth (%d)." % - (bitdepth, info['bitdepth'])) - info['bitdepth'] = bitdepth - - # Fill in and/or check entries in *info*. - # Dimensions. - if 'size' in info: - # Check width, height, size all match where used. - for dimension,axis in [('width', 0), ('height', 1)]: - if dimension in info: - if info[dimension] != info['size'][axis]: - raise Error( - "info[%r] should match info['size'][%r]." % - (dimension, axis)) - info['width'],info['height'] = info['size'] - if 'height' not in info: - try: - l = len(a) - except TypeError: - raise Error( - "len(a) does not work, supply info['height'] instead.") - info['height'] = l - # Colour format. - if 'greyscale' in info: - if bool(info['greyscale']) != ('L' in mode): - raise Error("info['greyscale'] should match mode.") - info['greyscale'] = 'L' in mode - if 'alpha' in info: - if bool(info['alpha']) != ('A' in mode): - raise Error("info['alpha'] should match mode.") - info['alpha'] = 'A' in mode - - planes = len(mode) - if 'planes' in info: - if info['planes'] != planes: - raise Error("info['planes'] should match mode.") - - # In order to work out whether we the array is 2D or 3D we need its - # first row, which requires that we take a copy of its iterator. - # We may also need the first row to derive width and bitdepth. - a,t = itertools.tee(a) - row = next(t) - del t - try: - row[0][0] - threed = True - testelement = row[0] - except (IndexError, TypeError): - threed = False - testelement = row - if 'width' not in info: - if threed: - width = len(row) - else: - width = len(row) // planes - info['width'] = width - - if threed: - # Flatten the threed rows - a = (itertools.chain.from_iterable(x) for x in a) - - if 'bitdepth' not in info: - try: - dtype = testelement.dtype - # goto the "else:" clause. Sorry. - except AttributeError: - try: - # Try a Python array.array. - bitdepth = 8 * testelement.itemsize - except AttributeError: - # We can't determine it from the array element's - # datatype, use a default of 8. - bitdepth = 8 - else: - # If we got here without exception, we now assume that - # the array is a numpy array. - if dtype.kind == 'b': - bitdepth = 1 - else: - bitdepth = 8 * dtype.itemsize - info['bitdepth'] = bitdepth - - for thing in 'width height bitdepth greyscale alpha'.split(): - assert thing in info - return Image(a, info) - -# So that refugee's from PIL feel more at home. Not documented. -fromarray = from_array - -class Image: - """A PNG image. You can create an :class:`Image` object from - an array of pixels by calling :meth:`png.from_array`. It can be - saved to disk with the :meth:`save` method. - """ - - def __init__(self, rows, info): - """ - .. note :: - - The constructor is not public. Please do not call it. - """ - - self.rows = rows - self.info = info - - def save(self, file): - """Save the image to *file*. If *file* looks like an open file - descriptor then it is used, otherwise it is treated as a - filename and a fresh file is opened. - - In general, you can only call this method once; after it has - been called the first time and the PNG image has been saved, the - source data will have been streamed, and cannot be streamed - again. - """ - - w = Writer(**self.info) - - try: - file.write - def close(): pass - except AttributeError: - file = open(file, 'wb') - def close(): file.close() - - try: - w.write(file, self.rows) - finally: - close() - -class _readable: - """ - A simple file-like interface for strings and arrays. - """ - - def __init__(self, buf): - self.buf = buf - self.offset = 0 - - def read(self, n): - r = self.buf[self.offset:self.offset+n] - if isarray(r): - r = r.tostring() - self.offset += n - return r - -try: - str(b'dummy', 'ascii') -except TypeError: - as_str = str -else: - def as_str(x): - return str(x, 'ascii') - -class Reader: - """ - PNG decoder in pure Python. - """ - - def __init__(self, _guess=None, **kw): - """ - Create a PNG decoder object. - - The constructor expects exactly one keyword argument. If you - supply a positional argument instead, it will guess the input - type. You can choose among the following keyword arguments: - - filename - Name of input file (a PNG file). - file - A file-like object (object with a read() method). - bytes - ``array`` or ``string`` with PNG data. - - """ - if ((_guess is not None and len(kw) != 0) or - (_guess is None and len(kw) != 1)): - raise TypeError("Reader() takes exactly 1 argument") - - # Will be the first 8 bytes, later on. See validate_signature. - self.signature = None - self.transparent = None - # A pair of (len,type) if a chunk has been read but its data and - # checksum have not (in other words the file position is just - # past the 4 bytes that specify the chunk type). See preamble - # method for how this is used. - self.atchunk = None - - if _guess is not None: - if isarray(_guess): - kw["bytes"] = _guess - elif isinstance(_guess, str): - kw["filename"] = _guess - elif hasattr(_guess, 'read'): - kw["file"] = _guess - - if "filename" in kw: - self.file = open(kw["filename"], "rb") - elif "file" in kw: - self.file = kw["file"] - elif "bytes" in kw: - self.file = _readable(kw["bytes"]) - else: - raise TypeError("expecting filename, file or bytes array") - - - def chunk(self, seek=None, lenient=False): - """ - Read the next PNG chunk from the input file; returns a - (*type*, *data*) tuple. *type* is the chunk's type as a - byte string (all PNG chunk types are 4 bytes long). - *data* is the chunk's data content, as a byte string. - - If the optional `seek` argument is - specified then it will keep reading chunks until it either runs - out of file or finds the type specified by the argument. Note - that in general the order of chunks in PNGs is unspecified, so - using `seek` can cause you to miss chunks. - - If the optional `lenient` argument evaluates to `True`, - checksum failures will raise warnings rather than exceptions. - """ - - self.validate_signature() - - while True: - # http://www.w3.org/TR/PNG/#5Chunk-layout - if not self.atchunk: - self.atchunk = self.chunklentype() - length, type = self.atchunk - self.atchunk = None - data = self.file.read(length) - if len(data) != length: - raise ChunkError('Chunk %s too short for required %i octets.' - % (type, length)) - checksum = self.file.read(4) - if len(checksum) != 4: - raise ChunkError('Chunk %s too short for checksum.' % type) - if seek and type != seek: - continue - verify = zlib.crc32(type) - verify = zlib.crc32(data, verify) - # Whether the output from zlib.crc32 is signed or not varies - # according to hideous implementation details, see - # http://bugs.python.org/issue1202 . - # We coerce it to be positive here (in a way which works on - # Python 2.3 and older). - verify &= 2**32 - 1 - verify = struct.pack('!I', verify) - if checksum != verify: - (a, ) = struct.unpack('!I', checksum) - (b, ) = struct.unpack('!I', verify) - message = "Checksum error in %s chunk: 0x%08X != 0x%08X." % (type, a, b) - if lenient: - warnings.warn(message, RuntimeWarning) - else: - raise ChunkError(message) - return type, data - - def chunks(self): - """Return an iterator that will yield each chunk as a - (*chunktype*, *content*) pair. - """ - - while True: - t,v = self.chunk() - yield t,v - if t == b'IEND': - break - - def undo_filter(self, filter_type, scanline, previous): - """Undo the filter for a scanline. `scanline` is a sequence of - bytes that does not include the initial filter type byte. - `previous` is decoded previous scanline (for straightlaced - images this is the previous pixel row, but for interlaced - images, it is the previous scanline in the reduced image, which - in general is not the previous pixel row in the final image). - When there is no previous scanline (the first row of a - straightlaced image, or the first row in one of the passes in an - interlaced image), then this argument should be ``None``. - - The scanline will have the effects of filtering removed, and the - result will be returned as a fresh sequence of bytes. - """ - - # :todo: Would it be better to update scanline in place? - # Yes, with the Cython extension making the undo_filter fast, - # updating scanline inplace makes the code 3 times faster - # (reading 50 images of 800x800 went from 40s to 16s) - result = scanline - - if filter_type == 0: - return result - - if filter_type not in (1,2,3,4): - raise FormatError('Invalid PNG Filter Type.' - ' See http://www.w3.org/TR/2003/REC-PNG-20031110/#9Filters .') - - # Filter unit. The stride from one pixel to the corresponding - # byte from the previous pixel. Normally this is the pixel - # size in bytes, but when this is smaller than 1, the previous - # byte is used instead. - fu = max(1, self.psize) - - # For the first line of a pass, synthesize a dummy previous - # line. An alternative approach would be to observe that on the - # first line 'up' is the same as 'null', 'paeth' is the same - # as 'sub', with only 'average' requiring any special case. - if not previous: - previous = array('B', [0]*len(scanline)) - - def sub(): - """Undo sub filter.""" - - ai = 0 - # Loop starts at index fu. Observe that the initial part - # of the result is already filled in correctly with - # scanline. - for i in range(fu, len(result)): - x = scanline[i] - a = result[ai] - result[i] = (x + a) & 0xff - ai += 1 - - def up(): - """Undo up filter.""" - - for i in range(len(result)): - x = scanline[i] - b = previous[i] - result[i] = (x + b) & 0xff - - def average(): - """Undo average filter.""" - - ai = -fu - for i in range(len(result)): - x = scanline[i] - if ai < 0: - a = 0 - else: - a = result[ai] - b = previous[i] - result[i] = (x + ((a + b) >> 1)) & 0xff - ai += 1 - - def paeth(): - """Undo Paeth filter.""" - - # Also used for ci. - ai = -fu - for i in range(len(result)): - x = scanline[i] - if ai < 0: - a = c = 0 - else: - a = result[ai] - c = previous[ai] - b = previous[i] - p = a + b - c - pa = abs(p - a) - pb = abs(p - b) - pc = abs(p - c) - if pa <= pb and pa <= pc: - pr = a - elif pb <= pc: - pr = b - else: - pr = c - result[i] = (x + pr) & 0xff - ai += 1 - - # Call appropriate filter algorithm. Note that 0 has already - # been dealt with. - (None, - pngfilters.undo_filter_sub, - pngfilters.undo_filter_up, - pngfilters.undo_filter_average, - pngfilters.undo_filter_paeth)[filter_type](fu, scanline, previous, result) - return result - - def deinterlace(self, raw): - """ - Read raw pixel data, undo filters, deinterlace, and flatten. - Return in flat row flat pixel format. - """ - - # Values per row (of the target image) - vpr = self.width * self.planes - - # Make a result array, and make it big enough. Interleaving - # writes to the output array randomly (well, not quite), so the - # entire output array must be in memory. - fmt = 'BH'[self.bitdepth > 8] - a = array(fmt, [0]*vpr*self.height) - source_offset = 0 - - for xstart, ystart, xstep, ystep in _adam7: - if xstart >= self.width: - continue - # The previous (reconstructed) scanline. None at the - # beginning of a pass to indicate that there is no previous - # line. - recon = None - # Pixels per row (reduced pass image) - ppr = int(math.ceil((self.width-xstart)/float(xstep))) - # Row size in bytes for this pass. - row_size = int(math.ceil(self.psize * ppr)) - for y in range(ystart, self.height, ystep): - filter_type = raw[source_offset] - source_offset += 1 - scanline = raw[source_offset:source_offset+row_size] - source_offset += row_size - recon = self.undo_filter(filter_type, scanline, recon) - # Convert so that there is one element per pixel value - flat = self.serialtoflat(recon, ppr) - if xstep == 1: - assert xstart == 0 - offset = y * vpr - a[offset:offset+vpr] = flat - else: - offset = y * vpr + xstart * self.planes - end_offset = (y+1) * vpr - skip = self.planes * xstep - for i in range(self.planes): - a[offset+i:end_offset:skip] = \ - flat[i::self.planes] - return a - - def iterboxed(self, rows): - """Iterator that yields each scanline in boxed row flat pixel - format. `rows` should be an iterator that yields the bytes of - each row in turn. - """ - - def asvalues(raw): - """Convert a row of raw bytes into a flat row. Result will - be a freshly allocated object, not shared with - argument. - """ - - if self.bitdepth == 8: - return array('B', raw) - if self.bitdepth == 16: - raw = tostring(raw) - return array('H', struct.unpack('!%dH' % (len(raw)//2), raw)) - assert self.bitdepth < 8 - width = self.width - # Samples per byte - spb = 8//self.bitdepth - out = array('B') - mask = 2**self.bitdepth - 1 - shifts = [self.bitdepth * i - for i in reversed(list(range(spb)))] - for o in raw: - out.extend([mask&(o>>i) for i in shifts]) - return out[:width] - - return map(asvalues, rows) - - def serialtoflat(self, bytes, width=None): - """Convert serial format (byte stream) pixel data to flat row - flat pixel. - """ - - if self.bitdepth == 8: - return bytes - if self.bitdepth == 16: - bytes = tostring(bytes) - return array('H', - struct.unpack('!%dH' % (len(bytes)//2), bytes)) - assert self.bitdepth < 8 - if width is None: - width = self.width - # Samples per byte - spb = 8//self.bitdepth - out = array('B') - mask = 2**self.bitdepth - 1 - shifts = list(map(self.bitdepth.__mul__, reversed(list(range(spb))))) - l = width - for o in bytes: - out.extend([(mask&(o>>s)) for s in shifts][:l]) - l -= spb - if l <= 0: - l = width - return out - - def iterstraight(self, raw): - """Iterator that undoes the effect of filtering, and yields - each row in serialised format (as a sequence of bytes). - Assumes input is straightlaced. `raw` should be an iterable - that yields the raw bytes in chunks of arbitrary size. - """ - - # length of row, in bytes - rb = self.row_bytes - a = array('B') - # The previous (reconstructed) scanline. None indicates first - # line of image. - recon = None - for some in raw: - a.extend(some) - while len(a) >= rb + 1: - filter_type = a[0] - scanline = a[1:rb+1] - del a[:rb+1] - recon = self.undo_filter(filter_type, scanline, recon) - yield recon - if len(a) != 0: - # :file:format We get here with a file format error: - # when the available bytes (after decompressing) do not - # pack into exact rows. - raise FormatError( - 'Wrong size for decompressed IDAT chunk.') - assert len(a) == 0 - - def validate_signature(self): - """If signature (header) has not been read then read and - validate it; otherwise do nothing. - """ - - if self.signature: - return - self.signature = self.file.read(8) - if self.signature != _signature: - raise FormatError("PNG file has invalid signature.") - - def preamble(self, lenient=False): - """ - Extract the image metadata by reading the initial part of - the PNG file up to the start of the ``IDAT`` chunk. All the - chunks that precede the ``IDAT`` chunk are read and either - processed for metadata or discarded. - - If the optional `lenient` argument evaluates to `True`, checksum - failures will raise warnings rather than exceptions. - """ - - self.validate_signature() - - while True: - if not self.atchunk: - self.atchunk = self.chunklentype() - if self.atchunk is None: - raise FormatError( - 'This PNG file has no IDAT chunks.') - if self.atchunk[1] == b'IDAT': - return - self.process_chunk(lenient=lenient) - - def chunklentype(self): - """Reads just enough of the input to determine the next - chunk's length and type, returned as a (*length*, *type*) pair - where *type* is a string. If there are no more chunks, ``None`` - is returned. - """ - - x = self.file.read(8) - if not x: - return None - if len(x) != 8: - raise FormatError( - 'End of file whilst reading chunk length and type.') - length,type = struct.unpack('!I4s', x) - if length > 2**31-1: - raise FormatError('Chunk %s is too large: %d.' % (type,length)) - return length,type - - def process_chunk(self, lenient=False): - """Process the next chunk and its data. This only processes the - following chunk types, all others are ignored: ``IHDR``, - ``PLTE``, ``bKGD``, ``tRNS``, ``gAMA``, ``sBIT``, ``pHYs``. - - If the optional `lenient` argument evaluates to `True`, - checksum failures will raise warnings rather than exceptions. - """ - - type, data = self.chunk(lenient=lenient) - method = '_process_' + as_str(type) - m = getattr(self, method, None) - if m: - m(data) - - def _process_IHDR(self, data): - # http://www.w3.org/TR/PNG/#11IHDR - if len(data) != 13: - raise FormatError('IHDR chunk has incorrect length.') - (self.width, self.height, self.bitdepth, self.color_type, - self.compression, self.filter, - self.interlace) = struct.unpack("!2I5B", data) - - check_bitdepth_colortype(self.bitdepth, self.color_type) - - if self.compression != 0: - raise Error("unknown compression method %d" % self.compression) - if self.filter != 0: - raise FormatError("Unknown filter method %d," - " see http://www.w3.org/TR/2003/REC-PNG-20031110/#9Filters ." - % self.filter) - if self.interlace not in (0,1): - raise FormatError("Unknown interlace method %d," - " see http://www.w3.org/TR/2003/REC-PNG-20031110/#8InterlaceMethods ." - % self.interlace) - - # Derived values - # http://www.w3.org/TR/PNG/#6Colour-values - colormap = bool(self.color_type & 1) - greyscale = not (self.color_type & 2) - alpha = bool(self.color_type & 4) - color_planes = (3,1)[greyscale or colormap] - planes = color_planes + alpha - - self.colormap = colormap - self.greyscale = greyscale - self.alpha = alpha - self.color_planes = color_planes - self.planes = planes - self.psize = float(self.bitdepth)/float(8) * planes - if int(self.psize) == self.psize: - self.psize = int(self.psize) - self.row_bytes = int(math.ceil(self.width * self.psize)) - # Stores PLTE chunk if present, and is used to check - # chunk ordering constraints. - self.plte = None - # Stores tRNS chunk if present, and is used to check chunk - # ordering constraints. - self.trns = None - # Stores sbit chunk if present. - self.sbit = None - - def _process_PLTE(self, data): - # http://www.w3.org/TR/PNG/#11PLTE - if self.plte: - warnings.warn("Multiple PLTE chunks present.") - self.plte = data - if len(data) % 3 != 0: - raise FormatError( - "PLTE chunk's length should be a multiple of 3.") - if len(data) > (2**self.bitdepth)*3: - raise FormatError("PLTE chunk is too long.") - if len(data) == 0: - raise FormatError("Empty PLTE is not allowed.") - - def _process_bKGD(self, data): - try: - if self.colormap: - if not self.plte: - warnings.warn( - "PLTE chunk is required before bKGD chunk.") - self.background = struct.unpack('B', data) - else: - self.background = struct.unpack("!%dH" % self.color_planes, - data) - except struct.error: - raise FormatError("bKGD chunk has incorrect length.") - - def _process_tRNS(self, data): - # http://www.w3.org/TR/PNG/#11tRNS - self.trns = data - if self.colormap: - if not self.plte: - warnings.warn("PLTE chunk is required before tRNS chunk.") - else: - if len(data) > len(self.plte)/3: - # Was warning, but promoted to Error as it - # would otherwise cause pain later on. - raise FormatError("tRNS chunk is too long.") - else: - if self.alpha: - raise FormatError( - "tRNS chunk is not valid with colour type %d." % - self.color_type) - try: - self.transparent = \ - struct.unpack("!%dH" % self.color_planes, data) - except struct.error: - raise FormatError("tRNS chunk has incorrect length.") - - def _process_gAMA(self, data): - try: - self.gamma = struct.unpack("!L", data)[0] / 100000.0 - except struct.error: - raise FormatError("gAMA chunk has incorrect length.") - - def _process_sBIT(self, data): - self.sbit = data - if (self.colormap and len(data) != 3 or - not self.colormap and len(data) != self.planes): - raise FormatError("sBIT chunk has incorrect length.") - - def _process_pHYs(self, data): - # http://www.w3.org/TR/PNG/#11pHYs - self.phys = data - fmt = "!LLB" - if len(data) != struct.calcsize(fmt): - raise FormatError("pHYs chunk has incorrect length.") - self.x_pixels_per_unit, self.y_pixels_per_unit, unit = struct.unpack(fmt,data) - self.unit_is_meter = bool(unit) - - def read(self, lenient=False): - """ - Read the PNG file and decode it. Returns (`width`, `height`, - `pixels`, `metadata`). - - May use excessive memory. - - `pixels` are returned in boxed row flat pixel format. - - If the optional `lenient` argument evaluates to True, - checksum failures will raise warnings rather than exceptions. - """ - - def iteridat(): - """Iterator that yields all the ``IDAT`` chunks as strings.""" - while True: - try: - type, data = self.chunk(lenient=lenient) - except ValueError as e: - raise ChunkError(e.args[0]) - if type == b'IEND': - # http://www.w3.org/TR/PNG/#11IEND - break - if type != b'IDAT': - continue - # type == b'IDAT' - # http://www.w3.org/TR/PNG/#11IDAT - if self.colormap and not self.plte: - warnings.warn("PLTE chunk is required before IDAT chunk") - yield data - - def iterdecomp(idat): - """Iterator that yields decompressed strings. `idat` should - be an iterator that yields the ``IDAT`` chunk data. - """ - - # Currently, with no max_length parameter to decompress, - # this routine will do one yield per IDAT chunk: Not very - # incremental. - d = zlib.decompressobj() - # Each IDAT chunk is passed to the decompressor, then any - # remaining state is decompressed out. - for data in idat: - # :todo: add a max_length argument here to limit output - # size. - yield array('B', d.decompress(data)) - yield array('B', d.flush()) - - self.preamble(lenient=lenient) - raw = iterdecomp(iteridat()) - - if self.interlace: - raw = array('B', itertools.chain(*raw)) - arraycode = 'BH'[self.bitdepth>8] - # Like :meth:`group` but producing an array.array object for - # each row. - pixels = map(lambda *row: array(arraycode, row), - *[iter(self.deinterlace(raw))]*self.width*self.planes) - else: - pixels = self.iterboxed(self.iterstraight(raw)) - meta = dict() - for attr in 'greyscale alpha planes bitdepth interlace'.split(): - meta[attr] = getattr(self, attr) - meta['size'] = (self.width, self.height) - for attr in 'gamma transparent background'.split(): - a = getattr(self, attr, None) - if a is not None: - meta[attr] = a - if self.plte: - meta['palette'] = self.palette() - return self.width, self.height, pixels, meta - - - def read_flat(self): - """ - Read a PNG file and decode it into flat row flat pixel format. - Returns (*width*, *height*, *pixels*, *metadata*). - - May use excessive memory. - - `pixels` are returned in flat row flat pixel format. - - See also the :meth:`read` method which returns pixels in the - more stream-friendly boxed row flat pixel format. - """ - - x, y, pixel, meta = self.read() - arraycode = 'BH'[meta['bitdepth']>8] - pixel = array(arraycode, itertools.chain(*pixel)) - return x, y, pixel, meta - - def palette(self, alpha='natural'): - """Returns a palette that is a sequence of 3-tuples or 4-tuples, - synthesizing it from the ``PLTE`` and ``tRNS`` chunks. These - chunks should have already been processed (for example, by - calling the :meth:`preamble` method). All the tuples are the - same size: 3-tuples if there is no ``tRNS`` chunk, 4-tuples when - there is a ``tRNS`` chunk. Assumes that the image is colour type - 3 and therefore a ``PLTE`` chunk is required. - - If the `alpha` argument is ``'force'`` then an alpha channel is - always added, forcing the result to be a sequence of 4-tuples. - """ - - if not self.plte: - raise FormatError( - "Required PLTE chunk is missing in colour type 3 image.") - plte = group(array('B', self.plte), 3) - if self.trns or alpha == 'force': - trns = array('B', self.trns or '') - trns.extend([255]*(len(plte)-len(trns))) - plte = list(map(operator.add, plte, group(trns, 1))) - return plte - - def asDirect(self): - """Returns the image data as a direct representation of an - ``x * y * planes`` array. This method is intended to remove the - need for callers to deal with palettes and transparency - themselves. Images with a palette (colour type 3) - are converted to RGB or RGBA; images with transparency (a - ``tRNS`` chunk) are converted to LA or RGBA as appropriate. - When returned in this format the pixel values represent the - colour value directly without needing to refer to palettes or - transparency information. - - Like the :meth:`read` method this method returns a 4-tuple: - - (*width*, *height*, *pixels*, *meta*) - - This method normally returns pixel values with the bit depth - they have in the source image, but when the source PNG has an - ``sBIT`` chunk it is inspected and can reduce the bit depth of - the result pixels; pixel values will be reduced according to - the bit depth specified in the ``sBIT`` chunk (PNG nerds should - note a single result bit depth is used for all channels; the - maximum of the ones specified in the ``sBIT`` chunk. An RGB565 - image will be rescaled to 6-bit RGB666). - - The *meta* dictionary that is returned reflects the `direct` - format and not the original source image. For example, an RGB - source image with a ``tRNS`` chunk to represent a transparent - colour, will have ``planes=3`` and ``alpha=False`` for the - source image, but the *meta* dictionary returned by this method - will have ``planes=4`` and ``alpha=True`` because an alpha - channel is synthesized and added. - - *pixels* is the pixel data in boxed row flat pixel format (just - like the :meth:`read` method). - - All the other aspects of the image data are not changed. - """ - - self.preamble() - - # Simple case, no conversion necessary. - if not self.colormap and not self.trns and not self.sbit: - return self.read() - - x,y,pixels,meta = self.read() - - if self.colormap: - meta['colormap'] = False - meta['alpha'] = bool(self.trns) - meta['bitdepth'] = 8 - meta['planes'] = 3 + bool(self.trns) - plte = self.palette() - def iterpal(pixels): - for row in pixels: - row = [plte[x] for x in row] - yield array('B', itertools.chain(*row)) - pixels = iterpal(pixels) - elif self.trns: - # It would be nice if there was some reasonable way - # of doing this without generating a whole load of - # intermediate tuples. But tuples does seem like the - # easiest way, with no other way clearly much simpler or - # much faster. (Actually, the L to LA conversion could - # perhaps go faster (all those 1-tuples!), but I still - # wonder whether the code proliferation is worth it) - it = self.transparent - maxval = 2**meta['bitdepth']-1 - planes = meta['planes'] - meta['alpha'] = True - meta['planes'] += 1 - typecode = 'BH'[meta['bitdepth']>8] - def itertrns(pixels): - for row in pixels: - # For each row we group it into pixels, then form a - # characterisation vector that says whether each - # pixel is opaque or not. Then we convert - # True/False to 0/maxval (by multiplication), - # and add it as the extra channel. - row = group(row, planes) - opa = map(it.__ne__, row) - opa = map(maxval.__mul__, opa) - opa = list(zip(opa)) # convert to 1-tuples - yield array(typecode, - itertools.chain(*map(operator.add, row, opa))) - pixels = itertrns(pixels) - targetbitdepth = None - if self.sbit: - sbit = struct.unpack('%dB' % len(self.sbit), self.sbit) - targetbitdepth = max(sbit) - if targetbitdepth > meta['bitdepth']: - raise Error('sBIT chunk %r exceeds bitdepth %d' % - (sbit,self.bitdepth)) - if min(sbit) <= 0: - raise Error('sBIT chunk %r has a 0-entry' % sbit) - if targetbitdepth == meta['bitdepth']: - targetbitdepth = None - if targetbitdepth: - shift = meta['bitdepth'] - targetbitdepth - meta['bitdepth'] = targetbitdepth - def itershift(pixels): - for row in pixels: - yield [p >> shift for p in row] - pixels = itershift(pixels) - return x,y,pixels,meta - - def asFloat(self, maxval=1.0): - """Return image pixels as per :meth:`asDirect` method, but scale - all pixel values to be floating point values between 0.0 and - *maxval*. - """ - - x,y,pixels,info = self.asDirect() - sourcemaxval = 2**info['bitdepth']-1 - del info['bitdepth'] - info['maxval'] = float(maxval) - factor = float(maxval)/float(sourcemaxval) - def iterfloat(): - for row in pixels: - yield [factor * p for p in row] - return x,y,iterfloat(),info - - def _as_rescale(self, get, targetbitdepth): - """Helper used by :meth:`asRGB8` and :meth:`asRGBA8`.""" - - width,height,pixels,meta = get() - maxval = 2**meta['bitdepth'] - 1 - targetmaxval = 2**targetbitdepth - 1 - factor = float(targetmaxval) / float(maxval) - meta['bitdepth'] = targetbitdepth - def iterscale(): - for row in pixels: - yield [int(round(x*factor)) for x in row] - if maxval == targetmaxval: - return width, height, pixels, meta - else: - return width, height, iterscale(), meta - - def asRGB8(self): - """Return the image data as an RGB pixels with 8-bits per - sample. This is like the :meth:`asRGB` method except that - this method additionally rescales the values so that they - are all between 0 and 255 (8-bit). In the case where the - source image has a bit depth < 8 the transformation preserves - all the information; where the source image has bit depth - > 8, then rescaling to 8-bit values loses precision. No - dithering is performed. Like :meth:`asRGB`, an alpha channel - in the source image will raise an exception. - - This function returns a 4-tuple: - (*width*, *height*, *pixels*, *metadata*). - *width*, *height*, *metadata* are as per the - :meth:`read` method. - - *pixels* is the pixel data in boxed row flat pixel format. - """ - - return self._as_rescale(self.asRGB, 8) - - def asRGBA8(self): - """Return the image data as RGBA pixels with 8-bits per - sample. This method is similar to :meth:`asRGB8` and - :meth:`asRGBA`: The result pixels have an alpha channel, *and* - values are rescaled to the range 0 to 255. The alpha channel is - synthesized if necessary (with a small speed penalty). - """ - - return self._as_rescale(self.asRGBA, 8) - - def asRGB(self): - """Return image as RGB pixels. RGB colour images are passed - through unchanged; greyscales are expanded into RGB - triplets (there is a small speed overhead for doing this). - - An alpha channel in the source image will raise an - exception. - - The return values are as for the :meth:`read` method - except that the *metadata* reflect the returned pixels, not the - source image. In particular, for this method - ``metadata['greyscale']`` will be ``False``. - """ - - width,height,pixels,meta = self.asDirect() - if meta['alpha']: - raise Error("will not convert image with alpha channel to RGB") - if not meta['greyscale']: - return width,height,pixels,meta - meta['greyscale'] = False - typecode = 'BH'[meta['bitdepth'] > 8] - def iterrgb(): - for row in pixels: - a = array(typecode, [0]) * 3 * width - for i in range(3): - a[i::3] = row - yield a - return width,height,iterrgb(),meta - - def asRGBA(self): - """Return image as RGBA pixels. Greyscales are expanded into - RGB triplets; an alpha channel is synthesized if necessary. - The return values are as for the :meth:`read` method - except that the *metadata* reflect the returned pixels, not the - source image. In particular, for this method - ``metadata['greyscale']`` will be ``False``, and - ``metadata['alpha']`` will be ``True``. - """ - - width,height,pixels,meta = self.asDirect() - if meta['alpha'] and not meta['greyscale']: - return width,height,pixels,meta - typecode = 'BH'[meta['bitdepth'] > 8] - maxval = 2**meta['bitdepth'] - 1 - maxbuffer = struct.pack('=' + typecode, maxval) * 4 * width - def newarray(): - return array(typecode, maxbuffer) - - if meta['alpha'] and meta['greyscale']: - # LA to RGBA - def convert(): - for row in pixels: - # Create a fresh target row, then copy L channel - # into first three target channels, and A channel - # into fourth channel. - a = newarray() - pngfilters.convert_la_to_rgba(row, a) - yield a - elif meta['greyscale']: - # L to RGBA - def convert(): - for row in pixels: - a = newarray() - pngfilters.convert_l_to_rgba(row, a) - yield a - else: - assert not meta['alpha'] and not meta['greyscale'] - # RGB to RGBA - def convert(): - for row in pixels: - a = newarray() - pngfilters.convert_rgb_to_rgba(row, a) - yield a - meta['alpha'] = True - meta['greyscale'] = False - return width,height,convert(),meta - -def check_bitdepth_colortype(bitdepth, colortype): - """Check that `bitdepth` and `colortype` are both valid, - and specified in a valid combination. Returns if valid, - raise an Exception if not valid. - """ - - if bitdepth not in (1,2,4,8,16): - raise FormatError("invalid bit depth %d" % bitdepth) - if colortype not in (0,2,3,4,6): - raise FormatError("invalid colour type %d" % colortype) - # Check indexed (palettized) images have 8 or fewer bits - # per pixel; check only indexed or greyscale images have - # fewer than 8 bits per pixel. - if colortype & 1 and bitdepth > 8: - raise FormatError( - "Indexed images (colour type %d) cannot" - " have bitdepth > 8 (bit depth %d)." - " See http://www.w3.org/TR/2003/REC-PNG-20031110/#table111 ." - % (bitdepth, colortype)) - if bitdepth < 8 and colortype not in (0,3): - raise FormatError("Illegal combination of bit depth (%d)" - " and colour type (%d)." - " See http://www.w3.org/TR/2003/REC-PNG-20031110/#table111 ." - % (bitdepth, colortype)) - -def isinteger(x): - try: - return int(x) == x - except (TypeError, ValueError): - return False - - -# === Support for users without Cython === - -try: - pngfilters -except NameError: - class pngfilters(object): - def undo_filter_sub(filter_unit, scanline, previous, result): - """Undo sub filter.""" - - ai = 0 - # Loops starts at index fu. Observe that the initial part - # of the result is already filled in correctly with - # scanline. - for i in range(filter_unit, len(result)): - x = scanline[i] - a = result[ai] - result[i] = (x + a) & 0xff - ai += 1 - undo_filter_sub = staticmethod(undo_filter_sub) - - def undo_filter_up(filter_unit, scanline, previous, result): - """Undo up filter.""" - - for i in range(len(result)): - x = scanline[i] - b = previous[i] - result[i] = (x + b) & 0xff - undo_filter_up = staticmethod(undo_filter_up) - - def undo_filter_average(filter_unit, scanline, previous, result): - """Undo up filter.""" - - ai = -filter_unit - for i in range(len(result)): - x = scanline[i] - if ai < 0: - a = 0 - else: - a = result[ai] - b = previous[i] - result[i] = (x + ((a + b) >> 1)) & 0xff - ai += 1 - undo_filter_average = staticmethod(undo_filter_average) - - def undo_filter_paeth(filter_unit, scanline, previous, result): - """Undo Paeth filter.""" - - # Also used for ci. - ai = -filter_unit - for i in range(len(result)): - x = scanline[i] - if ai < 0: - a = c = 0 - else: - a = result[ai] - c = previous[ai] - b = previous[i] - p = a + b - c - pa = abs(p - a) - pb = abs(p - b) - pc = abs(p - c) - if pa <= pb and pa <= pc: - pr = a - elif pb <= pc: - pr = b - else: - pr = c - result[i] = (x + pr) & 0xff - ai += 1 - undo_filter_paeth = staticmethod(undo_filter_paeth) - - def convert_la_to_rgba(row, result): - for i in range(3): - result[i::4] = row[0::2] - result[3::4] = row[1::2] - convert_la_to_rgba = staticmethod(convert_la_to_rgba) - - def convert_l_to_rgba(row, result): - """Convert a grayscale image to RGBA. This method assumes - the alpha channel in result is already correctly - initialized. - """ - for i in range(3): - result[i::4] = row - convert_l_to_rgba = staticmethod(convert_l_to_rgba) - - def convert_rgb_to_rgba(row, result): - """Convert an RGB image to RGBA. This method assumes the - alpha channel in result is already correctly initialized. - """ - for i in range(3): - result[i::4] = row[i::3] - convert_rgb_to_rgba = staticmethod(convert_rgb_to_rgba) - - -# === Command Line Support === - -def read_pam_header(infile): - """ - Read (the rest of a) PAM header. `infile` should be positioned - immediately after the initial 'P7' line (at the beginning of the - second line). Returns are as for `read_pnm_header`. - """ - - # Unlike PBM, PGM, and PPM, we can read the header a line at a time. - header = dict() - while True: - l = infile.readline().strip() - if l == b'ENDHDR': - break - if not l: - raise EOFError('PAM ended prematurely') - if l[0] == b'#': - continue - l = l.split(None, 1) - if l[0] not in header: - header[l[0]] = l[1] - else: - header[l[0]] += b' ' + l[1] - - required = [b'WIDTH', b'HEIGHT', b'DEPTH', b'MAXVAL'] - WIDTH,HEIGHT,DEPTH,MAXVAL = required - present = [x for x in required if x in header] - if len(present) != len(required): - raise Error('PAM file must specify WIDTH, HEIGHT, DEPTH, and MAXVAL') - width = int(header[WIDTH]) - height = int(header[HEIGHT]) - depth = int(header[DEPTH]) - maxval = int(header[MAXVAL]) - if (width <= 0 or - height <= 0 or - depth <= 0 or - maxval <= 0): - raise Error( - 'WIDTH, HEIGHT, DEPTH, MAXVAL must all be positive integers') - return 'P7', width, height, depth, maxval - -def read_pnm_header(infile, supported=(b'P5', b'P6')): - """ - Read a PNM header, returning (format,width,height,depth,maxval). - `width` and `height` are in pixels. `depth` is the number of - channels in the image; for PBM and PGM it is synthesized as 1, for - PPM as 3; for PAM images it is read from the header. `maxval` is - synthesized (as 1) for PBM images. - """ - - # Generally, see http://netpbm.sourceforge.net/doc/ppm.html - # and http://netpbm.sourceforge.net/doc/pam.html - - # Technically 'P7' must be followed by a newline, so by using - # rstrip() we are being liberal in what we accept. I think this - # is acceptable. - type = infile.read(3).rstrip() - if type not in supported: - raise NotImplementedError('file format %s not supported' % type) - if type == b'P7': - # PAM header parsing is completely different. - return read_pam_header(infile) - # Expected number of tokens in header (3 for P4, 4 for P6) - expected = 4 - pbm = (b'P1', b'P4') - if type in pbm: - expected = 3 - header = [type] - - # We have to read the rest of the header byte by byte because the - # final whitespace character (immediately following the MAXVAL in - # the case of P6) may not be a newline. Of course all PNM files in - # the wild use a newline at this point, so it's tempting to use - # readline; but it would be wrong. - def getc(): - c = infile.read(1) - if not c: - raise Error('premature EOF reading PNM header') - return c - - c = getc() - while True: - # Skip whitespace that precedes a token. - while c.isspace(): - c = getc() - # Skip comments. - while c == '#': - while c not in b'\n\r': - c = getc() - if not c.isdigit(): - raise Error('unexpected character %s found in header' % c) - # According to the specification it is legal to have comments - # that appear in the middle of a token. - # This is bonkers; I've never seen it; and it's a bit awkward to - # code good lexers in Python (no goto). So we break on such - # cases. - token = b'' - while c.isdigit(): - token += c - c = getc() - # Slight hack. All "tokens" are decimal integers, so convert - # them here. - header.append(int(token)) - if len(header) == expected: - break - # Skip comments (again) - while c == '#': - while c not in '\n\r': - c = getc() - if not c.isspace(): - raise Error('expected header to end with whitespace, not %s' % c) - - if type in pbm: - # synthesize a MAXVAL - header.append(1) - depth = (1,3)[type == b'P6'] - return header[0], header[1], header[2], depth, header[3] - -def write_pnm(file, width, height, pixels, meta): - """Write a Netpbm PNM/PAM file. - """ - - bitdepth = meta['bitdepth'] - maxval = 2**bitdepth - 1 - # Rudely, the number of image planes can be used to determine - # whether we are L (PGM), LA (PAM), RGB (PPM), or RGBA (PAM). - planes = meta['planes'] - # Can be an assert as long as we assume that pixels and meta came - # from a PNG file. - assert planes in (1,2,3,4) - if planes in (1,3): - if 1 == planes: - # PGM - # Could generate PBM if maxval is 1, but we don't (for one - # thing, we'd have to convert the data, not just blat it - # out). - fmt = 'P5' - else: - # PPM - fmt = 'P6' - header = '%s %d %d %d\n' % (fmt, width, height, maxval) - if planes in (2,4): - # PAM - # See http://netpbm.sourceforge.net/doc/pam.html - if 2 == planes: - tupltype = 'GRAYSCALE_ALPHA' - else: - tupltype = 'RGB_ALPHA' - header = ('P7\nWIDTH %d\nHEIGHT %d\nDEPTH %d\nMAXVAL %d\n' - 'TUPLTYPE %s\nENDHDR\n' % - (width, height, planes, maxval, tupltype)) - file.write(header.encode('ascii')) - # Values per row - vpr = planes * width - # struct format - fmt = '>%d' % vpr - if maxval > 0xff: - fmt = fmt + 'H' - else: - fmt = fmt + 'B' - for row in pixels: - file.write(struct.pack(fmt, *row)) - file.flush() - -def color_triple(color): - """ - Convert a command line colour value to a RGB triple of integers. - FIXME: Somewhere we need support for greyscale backgrounds etc. - """ - if color.startswith('#') and len(color) == 4: - return (int(color[1], 16), - int(color[2], 16), - int(color[3], 16)) - if color.startswith('#') and len(color) == 7: - return (int(color[1:3], 16), - int(color[3:5], 16), - int(color[5:7], 16)) - elif color.startswith('#') and len(color) == 13: - return (int(color[1:5], 16), - int(color[5:9], 16), - int(color[9:13], 16)) - -def _add_common_options(parser): - """Call *parser.add_option* for each of the options that are - common between this PNG--PNM conversion tool and the gen - tool. - """ - parser.add_option("-i", "--interlace", - default=False, action="store_true", - help="create an interlaced PNG file (Adam7)") - parser.add_option("-t", "--transparent", - action="store", type="string", metavar="#RRGGBB", - help="mark the specified colour as transparent") - parser.add_option("-b", "--background", - action="store", type="string", metavar="#RRGGBB", - help="save the specified background colour") - parser.add_option("-g", "--gamma", - action="store", type="float", metavar="value", - help="save the specified gamma value") - parser.add_option("-c", "--compression", - action="store", type="int", metavar="level", - help="zlib compression level (0-9)") - return parser - -def _main(argv): - """ - Run the PNG encoder with options from the command line. - """ - - # Parse command line arguments - from optparse import OptionParser - version = '%prog ' + __version__ - parser = OptionParser(version=version) - parser.set_usage("%prog [options] [imagefile]") - parser.add_option('-r', '--read-png', default=False, - action='store_true', - help='Read PNG, write PNM') - parser.add_option("-a", "--alpha", - action="store", type="string", metavar="pgmfile", - help="alpha channel transparency (RGBA)") - _add_common_options(parser) - - (options, args) = parser.parse_args(args=argv[1:]) - - # Convert options - if options.transparent is not None: - options.transparent = color_triple(options.transparent) - if options.background is not None: - options.background = color_triple(options.background) - - # Prepare input and output files - if len(args) == 0: - infilename = '-' - infile = sys.stdin - elif len(args) == 1: - infilename = args[0] - infile = open(infilename, 'rb') - else: - parser.error("more than one input file") - outfile = sys.stdout - if sys.platform == "win32": - import msvcrt, os - msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY) - - if options.read_png: - # Encode PNG to PPM - png = Reader(file=infile) - width,height,pixels,meta = png.asDirect() - write_pnm(outfile, width, height, pixels, meta) - else: - # Encode PNM to PNG - format, width, height, depth, maxval = \ - read_pnm_header(infile, (b'P5',b'P6',b'P7')) - # When it comes to the variety of input formats, we do something - # rather rude. Observe that L, LA, RGB, RGBA are the 4 colour - # types supported by PNG and that they correspond to 1, 2, 3, 4 - # channels respectively. So we use the number of channels in - # the source image to determine which one we have. We do not - # care about TUPLTYPE. - greyscale = depth <= 2 - pamalpha = depth in (2,4) - supported = [2**x-1 for x in range(1,17)] - try: - mi = supported.index(maxval) - except ValueError: - raise NotImplementedError( - 'your maxval (%s) not in supported list %s' % - (maxval, str(supported))) - bitdepth = mi+1 - writer = Writer(width, height, - greyscale=greyscale, - bitdepth=bitdepth, - interlace=options.interlace, - transparent=options.transparent, - background=options.background, - alpha=bool(pamalpha or options.alpha), - gamma=options.gamma, - compression=options.compression) - if options.alpha: - pgmfile = open(options.alpha, 'rb') - format, awidth, aheight, adepth, amaxval = \ - read_pnm_header(pgmfile, 'P5') - if amaxval != '255': - raise NotImplementedError( - 'maxval %s not supported for alpha channel' % amaxval) - if (awidth, aheight) != (width, height): - raise ValueError("alpha channel image size mismatch" - " (%s has %sx%s but %s has %sx%s)" - % (infilename, width, height, - options.alpha, awidth, aheight)) - writer.convert_ppm_and_pgm(infile, pgmfile, outfile) - else: - writer.convert_pnm(infile, outfile) - - -if __name__ == '__main__': - try: - _main(sys.argv) - except Error as e: - print(e, file=sys.stderr) diff --git a/tools/unnamed.py b/tools/unnamed.py index c5d032083..53c5eebad 100755 --- a/tools/unnamed.py +++ b/tools/unnamed.py @@ -1,4 +1,5 @@ #!/usr/bin/env python3 +# -*- coding: utf-8 -*- from sys import stderr, exit from subprocess import Popen, PIPE diff --git a/tools/used_space.py b/tools/used_space.py index 34f8e492d..0ce3b11f7 100755 --- a/tools/used_space.py +++ b/tools/used_space.py @@ -8,9 +8,9 @@ Generate a PNG visualizing the space used by each bank in the ROM. """ import sys -from pokemontools import png from colorsys import hls_to_rgb +import png from mapreader import MapReader def main():