From a8be0ae4b6b2c32433ef24616d06f4d50e518b3e Mon Sep 17 00:00:00 2001
From: cristy <urban-warrior@git.imagemagick.org>
Date: Wed, 2 Apr 2014 21:10:45 +0000
Subject: [PATCH]

---
 MagickCore/quantize.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MagickCore/quantize.c b/MagickCore/quantize.c
index 4c5f0c54e..9a879062d 100644
--- a/MagickCore/quantize.c
+++ b/MagickCore/quantize.c
@@ -2767,6 +2767,8 @@ MagickExport MagickBooleanType QuantizeImage(const QuantizeInfo *quantize_info,
         depth--;
       if ((image->alpha_trait == BlendPixelTrait) && (depth > 5))
         depth--;
+      if (IsImageGray(image,exception) != MagickFalse)
+        depth=MaxTreeDepth;
     }
   /*
     Initialize color cube.
-- 
2.50.1