Merge pull request #5011 from Beep6581/colortoning-labregions-cdl

Enhanced version of the "L*a*b* regions" color toning

rtengine/procparams.h

@@ -454,13 +454,18 @@ struct ColorToningParams {
     static const double LABGRID_CORR_SCALE;
 
     struct LabCorrectionRegion {
+        enum { CHAN_ALL = -1, CHAN_R, CHAN_G, CHAN_B };
         double a;
         double b;
         double saturation;
-        double lightness;
+        double slope;
+        double offset;
+        double power;
         std::vector<double> hueMask;
         std::vector<double> chromaticityMask;
         std::vector<double> lightnessMask;
+        double maskBlur;
+        int channel;
 
         LabCorrectionRegion();
         bool operator==(const LabCorrectionRegion &other) const;