- Added ruby-vips gem

- [MISSING] some commands

image_processing.gemspec

@@ -20,5 +20,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "minitest-hooks"
   spec.add_development_dependency "minispec-metadata"
   spec.add_development_dependency "mini_magick", ">= 4.3.5"
+  spec.add_development_dependency "ruby-vips", ">= 2.0.0"
   spec.add_development_dependency "phashion" unless RUBY_ENGINE == "jruby"
 end

lib/image_processing/vips.rb

@@ -0,0 +1,83 @@
+require "image_processing/version"
+require "vips"
+require "tempfile"
+
+module ImageProcessing
+  module Vips
+    module_function
+
+    def convert!(image, format, page = nil, &block)
+      with_ruby_vips(image) do |img|
+        tmp_name = tmp_name(image.path, "_tmp.#{format}")
+        img.write_to_file(tmp_name)
+        tmp_name
+      end
+    end
+
+    def auto_orient!(image)
+      with_ruby_vips(image) do |img|
+        img.autorot
+        tmp_name = tmp_name(image.path)
+        img.write_to_file(tmp_name)
+        tmp_name
+      end
+    end
+
+    def resize_to_limit!(image, width, height)
+      with_ruby_vips(image) do |img|
+        img = resize_image(img, width, height) if width < img.width || height < img.height
+        tmp_name = tmp_name(image.path)
+        img.write_to_file(tmp_name)
+        tmp_name
+      end
+    end
+
+    def resize_to_fit!(image, width, height)
+      with_ruby_vips(image) do |img|
+        img = resize_image(img, width, height)
+        tmp_name = tmp_name(image.path)
+        img.write_to_file(tmp_name)
+        tmp_name
+      end
+    end
+    # Convert an image into a MiniMagick::Image for the duration of the block,
+    # and at the end return a File object.
+    def with_ruby_vips(image)
+      image = ::Vips::Image.new_from_file image.path
+      file_path = yield image
+      File.new(file_path)
+    end
+
+    # Creates a copy of the file and stores it into a Tempfile. Works for any
+    # IO object that responds to `#read(length = nil, outbuf = nil)`.
+    def _copy_to_tempfile(file)
+      extension = File.extname(file.path) if file.respond_to?(:path)
+      tempfile = Tempfile.new(["vips", extension.to_s], binmode: true)
+      IO.copy_stream(file, tempfile.path)
+      file.rewind
+      tempfile
+    end
+
+    def tmp_name(path, ext='_tmp\1')
+      ext_regex = /(\.[[:alnum:]]+)$/
+      path.sub(ext_regex, ext)
+    end
+
+    def resize_image(image, width, height, min_or_max = :min)
+      ratio = get_ratio image, width, height, min_or_max
+      return image if ratio == 1
+      image = if ratio > 1
+                image.resize(ratio, kernel: :nearest)
+              else
+                image.resize(ratio, kernel: :cubic)
+              end
+      image
+    end
+
+    def get_ratio(image, width,height, min_or_max = :min)
+      width_ratio = width.to_f / image.width
+      height_ratio = height.to_f / image.height
+      [width_ratio, height_ratio].send(min_or_max)
+    end
+  end
+end

test/vips_test.rb

@@ -0,0 +1,92 @@
+require "test_helper"
+require "mini_magick"
+require "image_processing/vips"
+require "stringio"
+
+describe ImageProcessing::Vips do
+  include ImageProcessing::Vips
+
+  def assert_similar(expected, actual)
+    return if RUBY_ENGINE == "jruby"
+
+    a = Phashion::Image.new(expected.path)
+    b = Phashion::Image.new(actual.path)
+
+    distance = a.distance_from(b).abs
+
+    assert_operator distance, :<, 2
+  end
+
+  def assert_dimensions(dimensions, file)
+    assert_equal dimensions, MiniMagick::Image.new(file.path).dimensions
+  end
+
+  def assert_type(type, file)
+    assert_equal type, MiniMagick::Image.new(file.path).type
+  end
+
+  def assert_resolution(resolution, file)
+    actual_resolution = MiniMagick::Image.new(file.path).resolution
+    # Travis has old imagemagick version
+    actual_resolution = actual_resolution.select(&:nonzero?) if ENV["CI"]
+    assert_equal resolution, actual_resolution
+  end
+
+  def fixture_image(name)
+    File.open("test/fixtures/#{name}")
+  end
+
+  before do
+    @portrait = _copy_to_tempfile(fixture_image("portrait.jpg"))
+    @landscape = _copy_to_tempfile(fixture_image("landscape.jpg"))
+  end
+
+
+  describe "#convert!" do
+    it "changes the image format" do
+      result = convert!(@portrait, "png")
+      assert_type "PNG", result
+    end
+  end
+
+  describe "#auto_orient!" do
+    it "fixes the orientation of the image" do
+      result = auto_orient!(@portrait)
+      assert_equal "1", MiniMagick::Image.new(result.path).exif["Orientation"]
+    end
+  end
+
+  describe "#resize_to_limit!" do
+    it "resizes the image up to a given limit" do
+      result = resize_to_limit!(@portrait, 400, 400)
+      assert_dimensions [300, 400], result
+    end
+
+    it "does not resize the image if it is smaller than the limit" do
+      result = resize_to_limit!(@portrait, 1000, 1000)
+      assert_dimensions [600, 800], result
+    end
+
+    it "produces correct image" do
+      result = resize_to_limit!(@portrait, 400, 400)
+      assert_similar fixture_image("limit.jpg"), result
+    end
+  end
+
+  describe "#resize_to_fit!" do
+    it "resizes the image to fit given dimensions" do
+      result = resize_to_fit!(@portrait, 400, 400)
+      assert_dimensions [300, 400], result
+    end
+
+    it "enlarges image if it is smaller than given dimensions" do
+      result = resize_to_fit!(@portrait, 1000, 1000)
+      assert_dimensions [750, 1000], result
+    end
+
+    it "produces correct image" do
+      result = resize_to_fit!(@portrait, 400, 400)
+      assert_similar fixture_image("fit.jpg"), result
+    end
+  end
+end