From 70e68a844517efda3094dc170a8f54affc9c82bc Mon Sep 17 00:00:00 2001
From: glennrp <glennrp@git.imagemagick.org>
Date: Fri, 1 Apr 2011 22:51:14 +0000
Subject: [PATCH] Make the png encoder treat incoming image depth as 8 if it is
 less than 8.

---
 coders/png.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/coders/png.c b/coders/png.c
index ac3ce4e32..67f187df9 100644
--- a/coders/png.c
+++ b/coders/png.c
@@ -7092,6 +7092,8 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
     }
 #endif
 
+  if (image->depth < 8)
+     image->depth=8;
 
 #if (MAGICKCORE_QUANTUM_DEPTH > 16)
   /* PNG does not handle depths greater than 16 so reduce it even
-- 
2.40.0