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Saturation.cpp
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// Copyright (c) 2008-2019 OpenShot Studios, LLC
//
// SPDX-License-Identifier: LGPL-3.0-or-later
#include "Saturation.h"
#include "Exceptions.h"
using namespace openshot;
Saturation::Saturation() : saturation(1.0), saturation_R(1.0), saturation_G(1.0), saturation_B(1.0) {
// Init effect properties
init_effect_details();
}
// Default constructor
Saturation::Saturation(Keyframe saturation, Keyframe saturation_R, Keyframe saturation_G, Keyframe saturation_B) :
saturation(saturation), saturation_R(saturation_R), saturation_G(saturation_G), saturation_B(saturation_B)
{
// Init effect properties
init_effect_details();
}
// Init effect settings
void Saturation::init_effect_details()
{
InitEffectInfo();
info.class_name = "Saturation";
info.name = "Color Saturation";
info.description = "Adjust the color saturation.";
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> Saturation::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
{
// Get the frame's image
std::shared_ptr<QImage> frame_image = frame->GetImage();
if (!frame_image)
return frame;
int pixel_count = frame_image->width() * frame_image->height();
// Get keyframe values for this frame
float saturation_value = saturation.GetValue(frame_number);
float saturation_value_R = saturation_R.GetValue(frame_number);
float saturation_value_G = saturation_G.GetValue(frame_number);
float saturation_value_B = saturation_B.GetValue(frame_number);
// Constants used for color saturation formula
const double pR = .299;
const double pG = .587;
const double pB = .114;
// Loop through pixels
unsigned char *pixels = (unsigned char *) frame_image->bits();
#pragma omp parallel for shared (pixels)
for (int pixel = 0; pixel < pixel_count; ++pixel)
{
// Calculate alpha % (to be used for removing pre-multiplied alpha value)
int A = pixels[pixel * 4 + 3];
float alpha_percent = A / 255.0;
// Get RGB values, and remove pre-multiplied alpha
int R = pixels[pixel * 4 + 0] / alpha_percent;
int G = pixels[pixel * 4 + 1] / alpha_percent;
int B = pixels[pixel * 4 + 2] / alpha_percent;
/*
* Common saturation adjustment
*/
// Calculate the saturation multiplier
double p = sqrt( (R * R * pR) +
(G * G * pG) +
(B * B * pB) );
// Adjust the saturation
R = constrain(p + (R - p) * saturation_value);
G = constrain(p + (G - p) * saturation_value);
B = constrain(p + (B - p) * saturation_value);
/*
* Color-separated saturation adjustment
*
* Splitting each of the three subpixels (R, G and B) into three distincs sub-subpixels (R, G and B in turn)
* which in their optical sum reproduce the original subpixel's color OR produce white light in the brightness
* of the original subpixel (dependening on the color channel's slider value).
*/
// Compute the brightness ("saturation multiplier") of the replaced subpixels
// Actually mathematical no-ops mostly, verbosity is kept just for clarification
const double p_r = sqrt(R * R * pR);
const double p_g = sqrt(G * G * pG);
const double p_b = sqrt(B * B * pB);
// Adjust the saturation
const int Rr = p_r + (R - p_r) * saturation_value_R;
const int Gr = p_r + (0 - p_r) * saturation_value_R;
const int Br = p_r + (0 - p_r) * saturation_value_R;
const int Rg = p_g + (0 - p_g) * saturation_value_G;
const int Gg = p_g + (G - p_g) * saturation_value_G;
const int Bg = p_g + (0 - p_g) * saturation_value_G;
const int Rb = p_b + (0 - p_b) * saturation_value_B;
const int Gb = p_b + (0 - p_b) * saturation_value_B;
const int Bb = p_b + (B - p_b) * saturation_value_B;
// Recombine brightness of sub-subpixels (Rx, Gx and Bx) into sub-pixels (R, G and B) again
R = Rr + Rg + Rb;
G = Gr + Gg + Gb;
B = Br + Bg + Bb;
// Constrain the value from 0 to 255
R = constrain(R);
G = constrain(G);
B = constrain(B);
// Set all pixels to new value
pixels[pixel * 4 + 0] = R;
pixels[pixel * 4 + 1] = G;
pixels[pixel * 4 + 2] = B;
// Pre-multiply the alpha back into the color channels
pixels[pixel * 4 + 0] *= alpha_percent;
pixels[pixel * 4 + 1] *= alpha_percent;
pixels[pixel * 4 + 2] *= alpha_percent;
}
// return the modified frame
return frame;
}
// Generate JSON string of this object
std::string Saturation::Json() const {
// Return formatted string
return JsonValue().toStyledString();
}
// Generate Json::Value for this object
Json::Value Saturation::JsonValue() const {
// Create root json object
Json::Value root = EffectBase::JsonValue(); // get parent properties
root["type"] = info.class_name;
root["saturation"] = saturation.JsonValue();
root["saturation_R"] = saturation_R.JsonValue();
root["saturation_G"] = saturation_G.JsonValue();
root["saturation_B"] = saturation_B.JsonValue();
// return JsonValue
return root;
}
// Load JSON string into this object
void Saturation::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 Saturation::SetJsonValue(const Json::Value root) {
// Set parent data
EffectBase::SetJsonValue(root);
// Set data from Json (if key is found)
if (!root["saturation"].isNull())
saturation.SetJsonValue(root["saturation"]);
if (!root["saturation_R"].isNull())
saturation_R.SetJsonValue(root["saturation_R"]);
if (!root["saturation_G"].isNull())
saturation_G.SetJsonValue(root["saturation_G"]);
if (!root["saturation_B"].isNull())
saturation_B.SetJsonValue(root["saturation_B"]);
}
// Get all properties for a specific frame
std::string Saturation::PropertiesJSON(int64_t requested_frame) const {
// Generate JSON properties list
Json::Value root = BasePropertiesJSON(requested_frame);
// Keyframes
root["saturation"] = add_property_json("Saturation", saturation.GetValue(requested_frame), "float", "", &saturation, 0.0, 4.0, false, requested_frame);
root["saturation_R"] = add_property_json("Saturation (Red)", saturation_R.GetValue(requested_frame), "float", "", &saturation_R, 0.0, 4.0, false, requested_frame);
root["saturation_G"] = add_property_json("Saturation (Green)", saturation_G.GetValue(requested_frame), "float", "", &saturation_G, 0.0, 4.0, false, requested_frame);
root["saturation_B"] = add_property_json("Saturation (Blue)", saturation_B.GetValue(requested_frame), "float", "", &saturation_B, 0.0, 4.0, false, requested_frame);
// Return formatted string
return root.toStyledString();
}
Exceptions.h
Header file for all Exception classes.
Saturation.h
Header file for Saturation class.
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::EffectBase::JsonValue
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Definition EffectBase.cpp:79
openshot::EffectBase::constrain
int constrain(int color_value)
Constrain a color value from 0 to 255.
Definition EffectBase.cpp:60
openshot::EffectBase::InitEffectInfo
void InitEffectInfo()
Definition EffectBase.cpp:24
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::EffectBase::SetJsonValue
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition EffectBase.cpp:115
openshot::EffectBase::info
EffectInfoStruct info
Information about the current effect.
Definition EffectBase.h:69
openshot::InvalidJSON
Exception for invalid JSON.
Definition Exceptions.h:218
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::Keyframe::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition KeyFrame.cpp:372
openshot::Keyframe::GetValue
double GetValue(int64_t index) const
Get the value at a specific index.
Definition KeyFrame.cpp:258
openshot::Keyframe::JsonValue
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition KeyFrame.cpp:339
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::Json
std::string Json() const override
Generate JSON string of this object.
Definition Saturation.cpp:151
openshot::Saturation::saturation_B
Keyframe saturation_B
Blue color saturation.
Definition Saturation.h:52
openshot::Saturation::Saturation
Saturation()
Blank constructor, useful when using Json to load the effect properties.
Definition Saturation.cpp:19
openshot::Saturation::PropertiesJSON
std::string PropertiesJSON(int64_t requested_frame) const override
Definition Saturation.cpp:207
openshot::Saturation::JsonValue
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition Saturation.cpp:158
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::SetJson
void SetJson(const std::string value) override
Load JSON string into this object.
Definition Saturation.cpp:173
openshot::Saturation::saturation
Keyframe saturation
Overall color saturation: 0.0 = greyscale, 1.0 = normal, 2.0 = double saturation.
Definition Saturation.h:49
openshot
This namespace is the default namespace for all code in the openshot library.
Definition Compressor.h:29
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition Json.cpp:16
openshot::EffectInfoStruct::has_video
bool has_video
Determines if this effect manipulates the image of a frame.
Definition EffectBase.h:40
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::name
std::string name
The name of the effect.
Definition EffectBase.h:37
openshot::EffectInfoStruct::description
std::string description
The description of this effect and what it does.
Definition EffectBase.h:38