Improve accuracy of Y to L conversion, fixes #4338

2018-01-29 21:17:34 +01:00
parent 24151b313a
commit e7d90ec1a2
9 changed files with 163 additions and 275 deletions
--- a/rtengine/ipvibrance.cc
+++ b/rtengine/ipvibrance.cc
@@ -700,7 +700,7 @@ void ImProcFunctions::vibrance (LabImage* lab)
                    aprovn = Chprov * sincosval.y;
                    bprovn = Chprov * sincosval.x;

-                    float fyy = (0.00862069f * Lprov ) + 0.137932f;
+                    float fyy = (Color::c1By116 * Lprov ) + Color::c16By116;
                    float fxx = (0.002f * aprovn) + fyy;
                    float fzz = fyy - (0.005f * bprovn);
                    float xx_ = 65535.f * Color::f2xyz (fxx) * Color::D50x;