GraphicsMagick: coders/bmp.c Default bit split for older BMPs wi...

changeset d338cdc9c5ab in /hg/GraphicsMagick
details: http://hg.GraphicsMagick.org/hg/GraphicsMagick?cmd=changeset;node=d338cdc9c5ab
summary: coders/bmp.c Default bit split for older BMPs with 32bpp and BI_BITFIELDS set is crazy.

diffstat:

 ChangeLog    |   6 ++++++
 coders/bmp.c |  22 ++++++++++++++++------
 2 files changed, 22 insertions(+), 6 deletions(-)

diffs (47 lines):

diff -r f6375160b0de -r d338cdc9c5ab ChangeLog
--- a/ChangeLog	Sat Sep 02 09:50:59 2023 -0500
+++ b/ChangeLog	Mon Sep 04 08:50:51 2023 +0200
@@ -1,3 +1,9 @@
+2023-09-04  Fojtik Jaroslav  <[email protected]>
+
+	* coders/bmp.c Default bit split for older BMPs with 32bpp and
+        BI_BITFIELDS set is crazy. Verified against IrFanView and 
+        bmpsuite-2.7.zip - image g/rgb32bf.bmp.
+
 2023-09-02  Bob Friesenhahn  <[email protected]>
 
 	* magick/resize.c (ResizeImage): Restore vertical/horizontal
diff -r f6375160b0de -r d338cdc9c5ab coders/bmp.c
--- a/coders/bmp.c	Sat Sep 02 09:50:59 2023 -0500
+++ b/coders/bmp.c	Mon Sep 04 08:50:51 2023 +0200
@@ -1416,14 +1416,24 @@
                 }
               if ( bmp_info.bits_per_pixel == 32)
                 {
-                  if(bmp_info.compression==BI_RGB || bmp_info.compression==BI_ALPHABITFIELDS)
+                  if(bmp_info.size<=52 && bmp_info.compression==BI_BITFIELDS)
+                  {
+                    bmp_info.blue_mask=0xFF0000;
+                    bmp_info.green_mask=0xFF0;		/* This is crazy :(. */
+                    bmp_info.red_mask=0xFF000000;
+                    /*bmp_info.alpha_mask=0x0; */
+                  }
+                  else
                   {
-                    image->matte = True;
-                    bmp_info.alpha_mask=0xff000000U;
+                    if(bmp_info.compression==BI_RGB || bmp_info.compression==BI_ALPHABITFIELDS)
+                    {
+                      image->matte = True;
+                      bmp_info.alpha_mask=0xff000000U;
+                    }
+                    bmp_info.red_mask=0x00ff0000U;
+                    bmp_info.green_mask=0x0000ff00U;
+                    bmp_info.blue_mask=0x000000ffU;
                   }
-                  bmp_info.red_mask=0x00ff0000U;
-                  bmp_info.green_mask=0x0000ff00U;
-                  bmp_info.blue_mask=0x000000ffU;
                 }
             }