From 0336d6d21c0a6f8364b11a4baa79b116762a54a0 Mon Sep 17 00:00:00 2001
From: cristy <urban-warrior@git.imagemagick.org>
Date: Thu, 22 Apr 2010 23:42:02 +0000
Subject: [PATCH]

---
 magick/colorspace.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/magick/colorspace.c b/magick/colorspace.c
index 04e8088a1..3a85abca8 100644
--- a/magick/colorspace.c
+++ b/magick/colorspace.c
@@ -149,8 +149,12 @@ static inline void ConvertXYZToLab(const double X,const double Y,const double Z,
   else
     z=(7.787037*z)+(16.0/116.0);
   *L=((116.0*y)-16.0)/100.0;
-  *a=0.5*(500.0*(x-y))/100.0+1.0;
-  *b=0.5*(200.0*(y-z))/100.0+1.0;
+  *a=(500.0*(x-y))/255.0;
+  if (*a < 0.0)
+    *a+=1.0;
+  *b=(200.0*(y-z))/255.0;
+  if (*b < 0.0)
+    *b+=1.0;
 }
 
 MagickExport MagickBooleanType RGBTransformImage(Image *image,
-- 
2.50.1