Add Outline effect class and integrate into OpenShot

bindings/python/openshot.i

@@ -114,6 +114,7 @@
         #include "effects/Stabilizer.h"
         #include "effects/Tracker.h"
         #include "effects/ObjectDetection.h"
+        #include "effects/Outline.h"
         #include "TrackedObjectBase.h"
         #include "TrackedObjectBBox.h"
     %}
@@ -351,4 +352,5 @@
     %include "effects/Stabilizer.h"
     %include "effects/Tracker.h"
     %include "effects/ObjectDetection.h"
+    %include "effects/Outline.h"
 #endif

src/CMakeLists.txt

@@ -99,6 +99,7 @@ set(OPENSHOT_CV_SOURCES
   effects/Stabilizer.cpp
   effects/Tracker.cpp
   effects/ObjectDetection.cpp
+  effects/Outline.cpp
   ./sort_filter/sort.cpp
   ./sort_filter/Hungarian.cpp
   ./sort_filter/KalmanTracker.cpp)

src/Effects.h

@@ -43,6 +43,7 @@
 
 /* OpenCV Effects */
 #ifdef USE_OPENCV
+#include "effects/Outline.h"
 #include "effects/ObjectDetection.h"
 #include "effects/Tracker.h"
 #include "effects/Stabilizer.h"

src/effects/Outline.cpp

@@ -0,0 +1,177 @@
+/**
+ * @file
+ * @brief Source file for Outline effect class
+ * @author Jonathan Thomas <jonathan@openshot.org>, Hai Vu <me@haivq.com>
+ *
+ * @ref License
+ */
+
+// Copyright (c) 2008-2019 OpenShot Studios, LLC
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+#include <opencv2/imgcodecs.hpp> 
+#include "Outline.h"
+#include "Exceptions.h"
+
+using namespace openshot;
+
+/// Blank constructor, useful when using Json to load the effect properties
+Outline::Outline() : width(3.0), red(0.0), green(0.0), blue(0.0), alpha(255.0) {
+	// Init effect properties
+	init_effect_details();
+}
+
+// Default constructor
+Outline::Outline(Keyframe width, Keyframe red, Keyframe green, Keyframe blue, Keyframe alpha) :
+	width(width), red(red), green(green), blue(blue), alpha(alpha)
+{
+	// Init effect properties
+	init_effect_details();
+}
+
+// Init effect settings
+void Outline::init_effect_details()
+{
+	/// Initialize the values of the EffectInfo struct.
+	InitEffectInfo();
+
+	/// Set the effect info
+	info.class_name = "Outline";
+	info.name = "Outline";
+	info.description = "Add outline around the image with transparent background.";
+	info.has_audio = false;
+	info.has_video = true;
+}
+
+// This method is required for all derived classes of EffectBase, and returns a
+// modified openshot::Frame object
+std::shared_ptr<openshot::Frame> Outline::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
+{
+	// Get the frame's image
+	std::shared_ptr<QImage> frame_image = frame->GetImage();
+
+	int sigmaValue = width.GetValue(frame_number) / 3;
+	int redValue = red.GetValue(frame_number);
+	int greenValue = green.GetValue(frame_number);
+	int blueValue = blue.GetValue(frame_number);
+	int alphaValue = alpha.GetValue(frame_number);
+	
+	// Get ARGB image from QImage
+	cv::Mat cv_image = QImageToARGBCvMat(frame_image);
+
+	// extract alpha channel to create the alpha mask from the image
+	std::vector<cv::Mat> channels(4);
+    cv::split(cv_image, channels);
+	cv::Mat alpha_mask = channels[3].clone();
+	cv::threshold(alpha_mask, alpha_mask, 254, 255, cv::ThresholdTypes::THRESH_BINARY); // threshold the alpha channel to remove aliased edges
+
+	
+	// Create the outline mask
+	cv::Mat outline_mask;
+	cv::GaussianBlur(alpha_mask, outline_mask, cv::Size(0, 0), sigmaValue, sigmaValue, cv::BorderTypes::BORDER_DEFAULT);
+	cv::threshold(outline_mask, outline_mask, 0, 255, cv::ThresholdTypes::THRESH_BINARY);
+
+	cv::Mat final_image;
+
+	// create solid color source mat
+	cv::Mat solid_color_mat(cv::Size(cv_image.cols, cv_image.rows), CV_8UC4, cv::Scalar(blueValue, greenValue, redValue, alphaValue));
+	
+	// place outline image first, then place the original image (de-antialiased) on top
+	solid_color_mat.copyTo(final_image, outline_mask);
+	cv_image.copyTo(final_image, alpha_mask);
+	
+	std::shared_ptr<QImage> new_frame_image = ARGBCvMatToQImage(final_image);
+
+	// FIXME: The shared_ptr::swap does not work somehow
+	// frame_image.swap(new_frame_image);
+	*frame_image = *new_frame_image;
+	
+	// return the modified frame
+	return frame;
+}
+
+cv::Mat Outline::QImageToARGBCvMat(std::shared_ptr<QImage>& qimage) {
+	return cv::Mat(qimage->height(), qimage->width(), CV_8UC4, (uchar*)qimage->constBits(), qimage->bytesPerLine());
+}
+
+std::shared_ptr<QImage> Outline::ARGBCvMatToQImage(cv::Mat img) {
+	QImage qimage(img.data, img.cols, img.rows, img.step, QImage::Format_ARGB32);
+	std::shared_ptr<QImage> imgIn = std::make_shared<QImage>(qimage.convertToFormat(QImage::Format_RGBA8888_Premultiplied));
+	return imgIn;
+}
+
+// Generate JSON string of this object
+std::string Outline::Json() const {
+
+	// Return formatted string
+	return JsonValue().toStyledString();
+}
+
+// Generate Json::Value for this object
+Json::Value Outline::JsonValue() const {
+
+	// Create root json object
+	Json::Value root = EffectBase::JsonValue(); // get parent properties
+	root["type"] = info.class_name;
+	root["width"] = width.JsonValue();
+	root["red"] = red.JsonValue();
+	root["green"] = green.JsonValue();
+	root["blue"] = blue.JsonValue();
+	root["alpha"] = alpha.JsonValue();
+
+	// return JsonValue
+	return root;
+}
+
+// Load JSON string into this object
+void Outline::SetJson(const std::string value) {
+
+	// Parse JSON string into JSON objects
+	try
+	{
+		const Json::Value root = openshot::stringToJson(value);
+		// Set all values that match
+		SetJsonValue(root);
+	}
+	catch (const std::exception& e)
+	{
+		// Error parsing JSON (or missing keys)
+		throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
+	}
+}
+
+// Load Json::Value into this object
+void Outline::SetJsonValue(const Json::Value root) {
+
+	// Set parent data
+	EffectBase::SetJsonValue(root);
+
+	// Set data from Json (if key is found)
+	if (!root["width"].isNull())
+		width.SetJsonValue(root["width"]);
+	if (!root["red"].isNull())
+		red.SetJsonValue(root["red"]);
+	if (!root["green"].isNull())
+		green.SetJsonValue(root["green"]);
+	if (!root["blue"].isNull())
+		blue.SetJsonValue(root["blue"]);
+	if (!root["alpha"].isNull())
+		alpha.SetJsonValue(root["alpha"]);
+}
+
+// Get all properties for a specific frame
+std::string Outline::PropertiesJSON(int64_t requested_frame) const {
+
+	// Generate JSON properties list
+	Json::Value root = BasePropertiesJSON(requested_frame);
+
+	// Keyframes
+	root["width"] = add_property_json("Width", width.GetValue(requested_frame), "float", "", &width, 0, 1000, false, requested_frame);
+	root["red"] = add_property_json("Red", red.GetValue(requested_frame), "float", "", &red, 0, 255, false, requested_frame);
+	root["green"] = add_property_json("Green", green.GetValue(requested_frame), "float", "", &green, 0, 255, false, requested_frame);
+	root["blue"] = add_property_json("Blue", blue.GetValue(requested_frame), "float", "", &blue, 0, 255, false, requested_frame);
+	root["alpha"] = add_property_json("Alpha", alpha.GetValue(requested_frame), "float", "", &alpha, 0, 255, false, requested_frame);
+
+	// Return formatted string
+	return root.toStyledString();
+}

src/effects/Outline.h

@@ -0,0 +1,99 @@
+/**
+ * @file
+ * @brief Header file for Outline effect class
+ * @author Jonathan Thomas <jonathan@openshot.org>, Hai Vu <me@haivq.com>
+ *
+ * @ref License
+ */
+
+// Copyright (c) 2008-2019 OpenShot Studios, LLC
+//
+// SPDX-License-Identifier: LGPL-3.0-or-later
+
+#ifndef OPENSHOT_OUTLINE_EFFECT_H
+#define OPENSHOT_OUTLINE_EFFECT_H
+
+#include "../EffectBase.h"
+
+#include "../Frame.h"
+#include "../Json.h"
+#include "../KeyFrame.h"
+
+#include <memory>
+#include <string>
+
+
+namespace openshot
+{
+
+	/**
+	 * @brief This class add the outline around image with transparent background and can be animated
+	 * with openshot::Keyframe curves over time.
+	 *
+	 * Since outline effect is pretty useful in many cases, this effect is added to libopenshot.
+	 */
+	class Outline : public EffectBase
+	{
+	private:
+		/// Init effect settings
+		void init_effect_details();
+
+		// Convert QImage to cv::Mat and vice versa
+		// Although Frame class has GetImageCV, but it does not include alpha channel
+		// so we need a separate methods which preserve alpha channel
+		// Idea from: https://stackoverflow.com/a/78480103
+		cv::Mat QImageToARGBCvMat(std::shared_ptr<QImage>& qimage);
+		std::shared_ptr<QImage> ARGBCvMatToQImage(cv::Mat img);
+
+	public:
+		Keyframe width;	///< Width of the outline
+		Keyframe red;	///< Red channel of the outline
+		Keyframe green;	///< Green of the outline
+		Keyframe blue;	///< Blue of the outline
+		Keyframe alpha;	///< Alpha of the outline
+
+		/// Blank constructor, useful when using Json to load the effect properties
+		Outline();
+
+		/// Default constructor, which require width
+		///
+		/// @param width the width of the outline (between 0 and 1000, rounded to int)
+		/// @param red the red channel of the outline (between 0 and 255, rounded to int)
+		/// @param green the green channel of the outline (between 0 and 255, rounded to int)
+		/// @param blue the blue channel of the outline (between 0 and 255, rounded to int)
+		/// @param alpha the alpha channel of the outline (between 0 and 255, rounded to int)
+		Outline(Keyframe width, Keyframe red, Keyframe green, Keyframe blue, Keyframe alpha);
+
+		/// @brief This method is required for all derived classes of ClipBase, and returns a
+		/// new openshot::Frame object. All Clip keyframes and effects are resolved into
+		/// pixels.
+		///
+		/// @returns A new openshot::Frame object
+		/// @param frame_number The frame number (starting at 1) of the clip or effect on the timeline.
+		std::shared_ptr<openshot::Frame> GetFrame(int64_t frame_number) override { return GetFrame(std::make_shared<openshot::Frame>(), frame_number); }
+
+		/// @brief This method is required for all derived classes of ClipBase, and returns a
+		/// modified openshot::Frame object
+		///
+		/// The frame object is passed into this method and used as a starting point (pixels and audio).
+		/// All Clip keyframes and effects are resolved into pixels.
+		///
+		/// @returns The modified openshot::Frame object
+		/// @param frame The frame object that needs the clip or effect applied to it
+		/// @param frame_number The frame number (starting at 1) of the clip or effect on the timeline.
+		std::shared_ptr<openshot::Frame> GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number) override;
+
+		// Get and Set JSON methods
+		std::string Json() const override; ///< Generate JSON string of this object
+		void SetJson(const std::string value) override; ///< Load JSON string into this object
+		Json::Value JsonValue() const override; ///< Generate Json::Value for this object
+		void SetJsonValue(const Json::Value root) override; ///< Load Json::Value into this object
+
+		/// Get all properties for a specific frame (perfect for a UI to display the current state
+		/// of all properties at any time)
+		std::string PropertiesJSON(int64_t requested_frame) const override;
+	};
+
+}
+
+#endif