From: glennrp <glennrp@git.imagemagick.org>
Date: Thu, 17 May 2012 02:33:23 +0000 (+0000)
Subject: Preserve colorspace info from gAMA, cHRM, and sRGB chunks.
X-Git-Tag: 7.0.1-0~5584
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8d0bca5eb90971dbd2100bb5d7a8de9e39f76595;p=imagemagick

Preserve colorspace info from gAMA, cHRM, and sRGB chunks.
---

diff --git a/coders/png.c b/coders/png.c
index 37fd9efe1..21ad20c59 100644
--- a/coders/png.c
+++ b/coders/png.c
@@ -2723,13 +2723,25 @@ static Image *ReadOnePNGImage(MngInfo *mng_info,
   image->columns=ping_width;
   image->rows=ping_height;
 
-  /* Note that the following sets image->gamma to 1.0, image->rendering_intent
-     to Undefined, and resets image->chromaticity, overriding any ancillary
-     chunk data from the PNG file.
-   */
   if (((int) ping_color_type == PNG_COLOR_TYPE_GRAY) ||
       ((int) ping_color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
-    SetImageColorspace(image,GRAYColorspace,exception);
+    {
+      if (!png_get_valid(ping,ping_info,PNG_INFO_gAMA) &&
+          !png_get_valid(ping,ping_info,PNG_INFO_cHRM) &&
+          !png_get_valid(ping,ping_info,PNG_INFO_sRGB))
+        {
+          /* Set image->gamma to 1.0, image->rendering_intent to Undefined,
+           * and reset image->chromaticity.
+           */
+          SetImageColorspace(image,GRAYColorspace,exception);
+        }
+    
+      else
+        {
+          /* Use colorspace data from PNG ancillary chunks */
+          image->colorspace=GRAYColorspace;
+        }
+    }
 
   if (((int) ping_color_type == PNG_COLOR_TYPE_PALETTE) ||
       ((int) ping_color_type == PNG_COLOR_TYPE_GRAY))