OpenShot Library | libopenshot  0.3.2
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 
16 using namespace openshot;
17 
19 Saturation::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
25 Saturation::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
33 void 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
48 std::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
151 std::string Saturation::Json() const {
152 
153  // Return formatted string
154  return JsonValue().toStyledString();
155 }
156 
157 // Generate Json::Value for this object
158 Json::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
173 void 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
190 void 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
207 std::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 }
openshot::ClipBase::add_property_json
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
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:16
openshot::EffectBase::info
EffectInfoStruct info
Information about the current effect.
Definition: EffectBase.h:69
openshot::Saturation::Json
std::string Json() const override
Generate JSON string of this object.
Definition: Saturation.cpp:151
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:28
openshot::EffectBase::JsonValue
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: EffectBase.cpp:79
openshot::Keyframe::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: KeyFrame.cpp:372
openshot::Saturation::saturation_R
Keyframe saturation_R
Red color saturation.
Definition: Saturation.h:50
openshot::Saturation::SetJsonValue
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition: Saturation.cpp:190
openshot::Saturation::JsonValue
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition: Saturation.cpp:158
openshot::Keyframe::JsonValue
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: KeyFrame.cpp:339
openshot::EffectBase::BasePropertiesJSON
Json::Value BasePropertiesJSON(int64_t requested_frame) const
Generate JSON object of base properties (recommended to be used by all effects)
Definition: EffectBase.cpp:179
openshot::Keyframe
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition: KeyFrame.h:53
openshot::InvalidJSON
Exception for invalid JSON.
Definition: Exceptions.h:217
openshot::EffectBase::InitEffectInfo
void InitEffectInfo()
Definition: EffectBase.cpp:24
openshot::EffectInfoStruct::has_audio
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition: EffectBase.h:41
openshot::EffectInfoStruct::class_name
std::string class_name
The class name of the effect.
Definition: EffectBase.h:36
openshot::EffectInfoStruct::description
std::string description
The description of this effect and what it does.
Definition: EffectBase.h:38
openshot::EffectInfoStruct::has_video
bool has_video
Determines if this effect manipulates the image of a frame.
Definition: EffectBase.h:40
openshot::Saturation::GetFrame
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
openshot::Saturation::saturation_G
Keyframe saturation_G
Green color saturation.
Definition: Saturation.h:51
openshot::Saturation::saturation_B
Keyframe saturation_B
Blue color saturation.
Definition: Saturation.h:52
openshot::EffectBase::constrain
int constrain(int color_value)
Constrain a color value from 0 to 255.
Definition: EffectBase.cpp:60
Saturation.h
Header file for Saturation class.
openshot::EffectInfoStruct::name
std::string name
The name of the effect.
Definition: EffectBase.h:37
openshot::Saturation::PropertiesJSON
std::string PropertiesJSON(int64_t requested_frame) const override
Definition: Saturation.cpp:207
openshot::Saturation::Saturation
Saturation()
Blank constructor, useful when using Json to load the effect properties.
Definition: Saturation.cpp:19
openshot::Saturation::SetJson
void SetJson(const std::string value) override
Load JSON string into this object.
Definition: Saturation.cpp:173
Exceptions.h
Header file for all Exception classes.
openshot::Saturation::saturation
Keyframe saturation
Overall color saturation: 0.0 = greyscale, 1.0 = normal, 2.0 = double saturation.
Definition: Saturation.h:49
openshot::EffectBase::SetJsonValue
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: EffectBase.cpp:115
openshot::Keyframe::GetValue
double GetValue(int64_t index) const
Get the value at a specific index.
Definition: KeyFrame.cpp:258