diff --git a/include/effects/Saturation.h b/include/effects/Saturation.h
index f272305f9..cc6976315 100644
--- a/include/effects/Saturation.h
+++ b/include/effects/Saturation.h
@@ -64,15 +64,21 @@ namespace openshot
void init_effect_details();
public:
- Keyframe saturation; ///< The color saturation: 0.0 = black and white, 1.0 = normal, 2.0 = double saturation
+ Keyframe saturation; ///< Overall color saturation: 0.0 = greyscale, 1.0 = normal, 2.0 = double saturation
+ Keyframe saturation_R; ///< Red color saturation
+ Keyframe saturation_G; ///< Green color saturation
+ Keyframe saturation_B; ///< Blue color saturation
/// Blank constructor, useful when using Json to load the effect properties
Saturation();
- /// Default constructor, which takes 1 curve, to adjust the color saturation over time.
+ /// Default constructor, which takes four curves (one common curve and one curve per color), to adjust the color saturation over time.
///
- /// @param new_saturation The curve to adjust the saturation of the frame's image (0.0 = black and white, 1.0 = normal, 2.0 = double saturation)
- Saturation(Keyframe new_saturation);
+ /// @param saturation The curve to adjust the saturation of the frame's image (0.0 = greyscale, 1.0 = normal, 2.0 = double saturation)
+ /// @param saturation_R The curve to adjust red saturation of the frame's image (0.0 = greyscale, 1.0 = normal, 2.0 = double saturation)
+ /// @param saturation_G The curve to adjust green saturation of the frame's image (0.0 = greyscale, 1.0 = normal, 2.0 = double saturation)
+ /// @param saturation_B The curve to adjust blue saturation of the frame's image (0.0 = greyscale, 1.0 = normal, 2.0 = double saturation)
+ Saturation(Keyframe saturation, Keyframe saturation_R, Keyframe saturation_G, Keyframe saturation_B);
/// @brief This method is required for all derived classes of EffectBase, and returns a
/// modified openshot::Frame object
diff --git a/src/effects/Saturation.cpp b/src/effects/Saturation.cpp
index d5c295eb2..cad9c08d7 100644
--- a/src/effects/Saturation.cpp
+++ b/src/effects/Saturation.cpp
@@ -33,13 +33,14 @@
using namespace openshot;
/// Blank constructor, useful when using Json to load the effect properties
-Saturation::Saturation() : saturation(1.0) {
+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 new_saturation) : saturation(new_saturation)
+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();
@@ -73,6 +74,9 @@ std::shared_ptr Saturation::GetFrame(std::shared_ptr frame, int64_
// 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;
@@ -90,15 +94,66 @@ std::shared_ptr Saturation::GetFrame(std::shared_ptr frame, int64_
int G = pixels[pixel * 4 + 1];
int B = pixels[pixel * 4 + 2];
+ /*
+ * Common saturation adjustment
+ */
+
// Calculate the saturation multiplier
double p = sqrt( (R * R * pR) +
- (G * G * pG) +
- (B * B * pB) );
-
- // Apply adjusted and constrained saturation
- pixels[pixel * 4] = constrain(p + (R - p) * saturation_value);
- pixels[pixel * 4 + 1] = constrain(p + (G - p) * saturation_value);
- pixels[pixel * 4 + 2] = constrain(p + (B - p) * saturation_value);
+ (G * G * pG) +
+ (B * B * pB) );
+
+ // Adjust the saturation
+ R = p + (R - p) * saturation_value;
+ G = p + (G - p) * saturation_value;
+ B = p + (B - p) * saturation_value;
+
+ // Constrain the value from 0 to 255
+ R = constrain(R);
+ G = constrain(G);
+ B = constrain(B);
+
+ /*
+ * 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] = R;
+ pixels[pixel * 4 + 1] = G;
+ pixels[pixel * 4 + 2] = B;
}
// return the modified frame
@@ -119,6 +174,9 @@ Json::Value Saturation::JsonValue() const {
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;
@@ -150,6 +208,12 @@ void Saturation::SetJsonValue(const Json::Value 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
@@ -166,6 +230,9 @@ std::string Saturation::PropertiesJSON(int64_t requested_frame) const {
// 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();