From: cristy <urban-warrior@git.imagemagick.org>
Date: Thu, 4 Apr 2013 16:53:36 +0000 (+0000)
Subject: (no commit message)
X-Git-Tag: 7.0.1-0~3949
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=09c3f68835c2e2642298044c73aff52c45ca5dbe;p=imagemagick

---

diff --git a/MagickCore/colorspace.c b/MagickCore/colorspace.c
index dbfef494d..6e336f87a 100644
--- a/MagickCore/colorspace.c
+++ b/MagickCore/colorspace.c
@@ -766,8 +766,8 @@ static MagickBooleanType sRGBTransformImage(Image *image,
           blue=DecodePixelGamma((MagickRealType) GetPixelBlue(image,q));
           ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
           ConvertXYZToLab(X,Y,Z,&L,&a,&b);
-          C=hypot(a,b);
-          H=180.0*atan2(b,a)/MagickPI;
+          C=hypot(a-0.5,b-0.5);
+          H=180.0*atan2(b-0.5,a-0.5)/MagickPI;
           if (H < 360.0)
             H+=360.0;
           if (H > 360.0)
@@ -2619,8 +2619,8 @@ static MagickBooleanType TransformsRGBImage(Image *image,
           L=QuantumScale*GetPixelRed(image,q);
           C=QuantumScale*GetPixelGreen(image,q);
           H=QuantumScale*GetPixelBlue(image,q);
-          a=C*cos(360.0*H*MagickPI/180.0);
-          b=C*sin(360.0*H*MagickPI/180.0);
+          a=C*cos(360.0*H*MagickPI/180.0)+0.5;
+          b=C*sin(360.0*H*MagickPI/180.0)+0.5;
           ConvertLabToXYZ(L,a,b,&X,&Y,&Z);
           ConvertXYZToRGB(X,Y,Z,&red,&green,&blue);
           SetPixelRed(image,ClampToQuantum(EncodePixelGamma(red)),q);
diff --git a/MagickCore/gem.c b/MagickCore/gem.c
index fb53d08f1..913a92c9d 100644
--- a/MagickCore/gem.c
+++ b/MagickCore/gem.c
@@ -107,8 +107,8 @@ MagickPrivate void ConvertHCLToRGB(const double hue,const double chroma,
   L=luma;
   C=chroma;
   H=hue;
-  a=C*cos(360.0*H*(MagickPI/180.0));
-  b=C*sin(360.0*H*(MagickPI/180.0));
+  a=C*cos(360.0*H*MagickPI/180.0)+0.5;
+  b=C*sin(360.0*H*MagickPI/180.0)+0.5;
   ConvertLabToXYZ(L,a,b,&X,&Y,&Z);
   ConvertXYZToRGB(X,Y,Z,red,green,blue);
 }
@@ -420,8 +420,8 @@ MagickPrivate void ConvertRGBToHCL(const double red,const double green,
   assert(luma != (double *) NULL);
   ConvertRGBToXYZ(red,green,blue,&X,&Y,&Z);
   ConvertXYZToLab(X,Y,Z,&L,&a,&b);
-  C=hypot(a,b);
-  H=180.0*atan2(b,a)/MagickPI;
+  C=hypot(a-0.5,b-0.5);
+  H=180.0*atan2(b-0.5,a-0.5)/MagickPI;
   if (H < 360.0)
     H+=360.0;
   if (H > 360.0)