OpenShot Library | libopenshot 0.3.3
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Saturation.cpp
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1
9// Copyright (c) 2008-2019 OpenShot Studios, LLC
10//
11// SPDX-License-Identifier: LGPL-3.0-or-later
12
13#include "Saturation.h"
14#include "Exceptions.h"
15
16using namespace openshot;
17
19Saturation::Saturation() : saturation(1.0), saturation_R(1.0), saturation_G(1.0), saturation_B(1.0) {
20 // Init effect properties
21 init_effect_details();
22}
23
24// Default constructor
25Saturation::Saturation(Keyframe saturation, Keyframe saturation_R, Keyframe saturation_G, Keyframe saturation_B) :
26 saturation(saturation), saturation_R(saturation_R), saturation_G(saturation_G), saturation_B(saturation_B)
27{
28 // Init effect properties
29 init_effect_details();
30}
31
32// Init effect settings
33void Saturation::init_effect_details()
34{
37
39 info.class_name = "Saturation";
40 info.name = "Color Saturation";
41 info.description = "Adjust the color saturation.";
42 info.has_audio = false;
43 info.has_video = true;
44}
45
46// This method is required for all derived classes of EffectBase, and returns a
47// modified openshot::Frame object
48std::shared_ptr<openshot::Frame> Saturation::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
49{
50 // Get the frame's image
51 std::shared_ptr<QImage> frame_image = frame->GetImage();
52
53 if (!frame_image)
54 return frame;
55
56 int pixel_count = frame_image->width() * frame_image->height();
57
58 // Get keyframe values for this frame
59 float saturation_value = saturation.GetValue(frame_number);
60 float saturation_value_R = saturation_R.GetValue(frame_number);
61 float saturation_value_G = saturation_G.GetValue(frame_number);
62 float saturation_value_B = saturation_B.GetValue(frame_number);
63
64 // Constants used for color saturation formula
65 const double pR = .299;
66 const double pG = .587;
67 const double pB = .114;
68
69 // Loop through pixels
70 unsigned char *pixels = (unsigned char *) frame_image->bits();
71
72 #pragma omp parallel for shared (pixels)
73 for (int pixel = 0; pixel < pixel_count; ++pixel)
74 {
75 // Calculate alpha % (to be used for removing pre-multiplied alpha value)
76 int A = pixels[pixel * 4 + 3];
77 float alpha_percent = A / 255.0;
78
79 // Get RGB values, and remove pre-multiplied alpha
80 int R = pixels[pixel * 4 + 0] / alpha_percent;
81 int G = pixels[pixel * 4 + 1] / alpha_percent;
82 int B = pixels[pixel * 4 + 2] / alpha_percent;
83
84 /*
85 * Common saturation adjustment
86 */
87
88 // Calculate the saturation multiplier
89 double p = sqrt( (R * R * pR) +
90 (G * G * pG) +
91 (B * B * pB) );
92
93 // Adjust the saturation
94 R = constrain(p + (R - p) * saturation_value);
95 G = constrain(p + (G - p) * saturation_value);
96 B = constrain(p + (B - p) * saturation_value);
97
98 /*
99 * Color-separated saturation adjustment
100 *
101 * Splitting each of the three subpixels (R, G and B) into three distincs sub-subpixels (R, G and B in turn)
102 * which in their optical sum reproduce the original subpixel's color OR produce white light in the brightness
103 * of the original subpixel (dependening on the color channel's slider value).
104 */
105
106 // Compute the brightness ("saturation multiplier") of the replaced subpixels
107 // Actually mathematical no-ops mostly, verbosity is kept just for clarification
108 const double p_r = sqrt(R * R * pR);
109 const double p_g = sqrt(G * G * pG);
110 const double p_b = sqrt(B * B * pB);
111
112 // Adjust the saturation
113 const int Rr = p_r + (R - p_r) * saturation_value_R;
114 const int Gr = p_r + (0 - p_r) * saturation_value_R;
115 const int Br = p_r + (0 - p_r) * saturation_value_R;
116
117 const int Rg = p_g + (0 - p_g) * saturation_value_G;
118 const int Gg = p_g + (G - p_g) * saturation_value_G;
119 const int Bg = p_g + (0 - p_g) * saturation_value_G;
120
121 const int Rb = p_b + (0 - p_b) * saturation_value_B;
122 const int Gb = p_b + (0 - p_b) * saturation_value_B;
123 const int Bb = p_b + (B - p_b) * saturation_value_B;
124
125 // Recombine brightness of sub-subpixels (Rx, Gx and Bx) into sub-pixels (R, G and B) again
126 R = Rr + Rg + Rb;
127 G = Gr + Gg + Gb;
128 B = Br + Bg + Bb;
129
130 // Constrain the value from 0 to 255
131 R = constrain(R);
132 G = constrain(G);
133 B = constrain(B);
134
135 // Set all pixels to new value
136 pixels[pixel * 4 + 0] = R;
137 pixels[pixel * 4 + 1] = G;
138 pixels[pixel * 4 + 2] = B;
139
140 // Pre-multiply the alpha back into the color channels
141 pixels[pixel * 4 + 0] *= alpha_percent;
142 pixels[pixel * 4 + 1] *= alpha_percent;
143 pixels[pixel * 4 + 2] *= alpha_percent;
144 }
145
146 // return the modified frame
147 return frame;
148}
149
150// Generate JSON string of this object
151std::string Saturation::Json() const {
152
153 // Return formatted string
154 return JsonValue().toStyledString();
155}
156
157// Generate Json::Value for this object
158Json::Value Saturation::JsonValue() const {
159
160 // Create root json object
161 Json::Value root = EffectBase::JsonValue(); // get parent properties
162 root["type"] = info.class_name;
163 root["saturation"] = saturation.JsonValue();
164 root["saturation_R"] = saturation_R.JsonValue();
165 root["saturation_G"] = saturation_G.JsonValue();
166 root["saturation_B"] = saturation_B.JsonValue();
167
168 // return JsonValue
169 return root;
170}
171
172// Load JSON string into this object
173void Saturation::SetJson(const std::string value) {
174
175 // Parse JSON string into JSON objects
176 try
177 {
178 const Json::Value root = openshot::stringToJson(value);
179 // Set all values that match
180 SetJsonValue(root);
181 }
182 catch (const std::exception& e)
183 {
184 // Error parsing JSON (or missing keys)
185 throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
186 }
187}
188
189// Load Json::Value into this object
190void Saturation::SetJsonValue(const Json::Value root) {
191
192 // Set parent data
194
195 // Set data from Json (if key is found)
196 if (!root["saturation"].isNull())
197 saturation.SetJsonValue(root["saturation"]);
198 if (!root["saturation_R"].isNull())
199 saturation_R.SetJsonValue(root["saturation_R"]);
200 if (!root["saturation_G"].isNull())
201 saturation_G.SetJsonValue(root["saturation_G"]);
202 if (!root["saturation_B"].isNull())
203 saturation_B.SetJsonValue(root["saturation_B"]);
204}
205
206// Get all properties for a specific frame
207std::string Saturation::PropertiesJSON(int64_t requested_frame) const {
208
209 // Generate JSON properties list
210 Json::Value root = BasePropertiesJSON(requested_frame);
211
212 // Keyframes
213 root["saturation"] = add_property_json("Saturation", saturation.GetValue(requested_frame), "float", "", &saturation, 0.0, 4.0, false, requested_frame);
214 root["saturation_R"] = add_property_json("Saturation (Red)", saturation_R.GetValue(requested_frame), "float", "", &saturation_R, 0.0, 4.0, false, requested_frame);
215 root["saturation_G"] = add_property_json("Saturation (Green)", saturation_G.GetValue(requested_frame), "float", "", &saturation_G, 0.0, 4.0, false, requested_frame);
216 root["saturation_B"] = add_property_json("Saturation (Blue)", saturation_B.GetValue(requested_frame), "float", "", &saturation_B, 0.0, 4.0, false, requested_frame);
217
218 // Return formatted string
219 return root.toStyledString();
220}
Header file for all Exception classes.
Header file for Saturation class.
Json::Value add_property_json(std::string name, float value, std::string type, std::string memo, const Keyframe *keyframe, float min_value, float max_value, bool readonly, int64_t requested_frame) const
Generate JSON for a property.
Definition ClipBase.cpp:96
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
int constrain(int color_value)
Constrain a color value from 0 to 255.
Json::Value BasePropertiesJSON(int64_t requested_frame) const
Generate JSON object of base properties (recommended to be used by all effects)
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
EffectInfoStruct info
Information about the current effect.
Definition EffectBase.h:69
Exception for invalid JSON.
Definition Exceptions.h:218
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition KeyFrame.h:53
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition KeyFrame.cpp:372
double GetValue(int64_t index) const
Get the value at a specific index.
Definition KeyFrame.cpp:258
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition KeyFrame.cpp:339
std::shared_ptr< openshot::Frame > GetFrame(int64_t frame_number) override
This method is required for all derived classes of ClipBase, and returns a new openshot::Frame object...
Definition Saturation.h:71
Keyframe saturation_G
Green color saturation.
Definition Saturation.h:51
std::string Json() const override
Generate JSON string of this object.
Keyframe saturation_B
Blue color saturation.
Definition Saturation.h:52
Saturation()
Blank constructor, useful when using Json to load the effect properties.
std::string PropertiesJSON(int64_t requested_frame) const override
Json::Value JsonValue() const override
Generate Json::Value for this object.
Keyframe saturation_R
Red color saturation.
Definition Saturation.h:50
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
void SetJson(const std::string value) override
Load JSON string into this object.
Keyframe saturation
Overall color saturation: 0.0 = greyscale, 1.0 = normal, 2.0 = double saturation.
Definition Saturation.h:49
This namespace is the default namespace for all code in the openshot library.
Definition Compressor.h:29
const Json::Value stringToJson(const std::string value)
Definition Json.cpp:16
bool has_video
Determines if this effect manipulates the image of a frame.
Definition EffectBase.h:40
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition EffectBase.h:41
std::string class_name
The class name of the effect.
Definition EffectBase.h:36
std::string name
The name of the effect.
Definition EffectBase.h:37
std::string description
The description of this effect and what it does.
Definition EffectBase.h:38