GraphicsMagick: ReadTIFFImage(): Require that TIFFTAG_EXTRASAMPL...

changeset 5c6fd2a5e177 in /hg/GraphicsMagick
details: http://hg.GraphicsMagick.org/hg/GraphicsMagick?cmd=changeset;node=5c6fd2a5e177
summary: ReadTIFFImage(): Require that TIFFTAG_EXTRASAMPLES be used appropriately to indicate the intention of extra channels.

diffstat:

 ChangeLog                              |   7 +++
 VisualMagick/installer/inc/version.isx |   4 +-
 coders/tiff.c                          |  68 +++++++++++++++++++---------------
 magick/version.h                       |   4 +-
 www/Changelog.html                     |   9 ++++
 5 files changed, 58 insertions(+), 34 deletions(-)

diffs (158 lines):

diff -r 4e6d0c85f96f -r 5c6fd2a5e177 ChangeLog
--- a/ChangeLog	Thu May 25 08:38:42 2023 -0500
+++ b/ChangeLog	Sat May 27 14:24:44 2023 -0500
@@ -1,3 +1,10 @@
+2023-05-27  Bob Friesenhahn  <[email protected]>
+
+	* coders/tiff.c (ReadTIFFImage): Require that TIFFTAG_EXTRASAMPLES
+	be used appropriately to indicate the intention of extra channels.
+	Otherwise extra samples beyond what is required by the photometric
+	will be ignored.
+
 2023-05-25  Bob Friesenhahn  <[email protected]>
 
 	* coders/tiff.c (ReadTIFFImage): Stop promoting RGB image to
diff -r 4e6d0c85f96f -r 5c6fd2a5e177 VisualMagick/installer/inc/version.isx
--- a/VisualMagick/installer/inc/version.isx	Thu May 25 08:38:42 2023 -0500
+++ b/VisualMagick/installer/inc/version.isx	Sat May 27 14:24:44 2023 -0500
@@ -10,5 +10,5 @@
 
 #define public MagickPackageName "GraphicsMagick"
 #define public MagickPackageVersion "1.4"
-#define public MagickPackageVersionAddendum ".020230525"
-#define public MagickPackageReleaseDate "snapshot-20230525"
+#define public MagickPackageVersionAddendum ".020230527"
+#define public MagickPackageReleaseDate "snapshot-20230527"
diff -r 4e6d0c85f96f -r 5c6fd2a5e177 coders/tiff.c
--- a/coders/tiff.c	Thu May 25 08:38:42 2023 -0500
+++ b/coders/tiff.c	Sat May 27 14:24:44 2023 -0500
@@ -736,6 +736,27 @@
   return result;
 }
 
+static const char *ExtraSampleToString(const unsigned int sample_info)
+{
+  const char
+    *result = "Unknown";
+
+  switch (sample_info)
+    {
+    case EXTRASAMPLE_UNSPECIFIED:
+      result="Unspecified data";
+      break;
+    case EXTRASAMPLE_ASSOCALPHA:
+      result="Associated alpha data (with pre-multiplied color)";
+      break;
+    case EXTRASAMPLE_UNASSALPHA:
+      result="Unassociated alpha data";
+      break;
+    }
+
+  return result;
+}
+
 /*
   Locate and store Photoshop or IPTC profiles.
 
@@ -2225,51 +2246,38 @@
 
           if (extra_samples != 0)
             {
-              /* FIXME: Is it ok to make this gross assumption? */
-              alpha_type=AssociatedAlpha;
-              image->matte=True;
-
               if (sample_info[0] == EXTRASAMPLE_UNSPECIFIED)
-                alpha_type=UnspecifiedAlpha;
+                {
+                  alpha_type=UnspecifiedAlpha;
+                }
               else if (sample_info[0] == EXTRASAMPLE_UNASSALPHA)
-                alpha_type=UnassociatedAlpha;
+                {
+                  alpha_type=UnassociatedAlpha;
+                  image->matte=True;
+                }
               else if (sample_info[0] == EXTRASAMPLE_ASSOCALPHA)
-                alpha_type=AssociatedAlpha;
+                {
+                  alpha_type=AssociatedAlpha;
+                  image->matte=True;
+                }
             }
           if (image->logging)
             for (sample_index=0 ; sample_index < extra_samples; sample_index++)
               {
                 (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-                                      "Extra sample %u contains %s alpha",sample_index+1,
-                                      ((sample_info[sample_index] == EXTRASAMPLE_ASSOCALPHA) ? "ASSOCIATED" :
-                                       (sample_info[sample_index] == EXTRASAMPLE_UNASSALPHA) ? "UNASSOCIATED" :
-                                       "UNSPECIFIED"));
+                                      "Extra sample %u contains %s",sample_index+1,
+                                      ExtraSampleToString(sample_info[sample_index]));
               }
         }
       /*
-        Handle RGBA images which are improperly marked.
+        Report RGBA images which may be improperly marked.
       */
-      if (extra_samples == 0)
+      if ((image->logging) && (extra_samples == 0))
         if ((photometric == PHOTOMETRIC_RGB) && (samples_per_pixel == 4))
           {
-#if 0
-
-            /*
-              FIXME: Temporarily (?) disabled until a solution is found
-               which does not cause issues.
-            */
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-                                  "Promoting RGB image to associated alpha due to"
-                                  " samples-per-pixel=%u", samples_per_pixel);
-            extra_samples=1;
-            alpha_type=AssociatedAlpha;
-            image->matte=MagickTrue;
-#else
-            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-                                  "Photometric is RGB but %u samples/pixel provided!",
-                                  samples_per_pixel);
-            ThrowTIFFReaderException(CorruptImageError,ImproperImageHeader,image);
-#endif
+                                  "Photometric is RGB but %u samples/pixel and %u extra_samples provided!",
+                                  samples_per_pixel, extra_samples);
           }
 
       /*
diff -r 4e6d0c85f96f -r 5c6fd2a5e177 magick/version.h
--- a/magick/version.h	Thu May 25 08:38:42 2023 -0500
+++ b/magick/version.h	Sat May 27 14:24:44 2023 -0500
@@ -38,8 +38,8 @@
 #define MagickLibVersion  0x272402
 #define MagickLibVersionText  "1.4"
 #define MagickLibVersionNumber 27,24,2
-#define MagickChangeDate   "20230525"
-#define MagickReleaseDate  "snapshot-20230525"
+#define MagickChangeDate   "20230527"
+#define MagickReleaseDate  "snapshot-20230527"
 
 /*
   The MagickLibInterfaceNewest and MagickLibInterfaceOldest defines
diff -r 4e6d0c85f96f -r 5c6fd2a5e177 www/Changelog.html
--- a/www/Changelog.html	Thu May 25 08:38:42 2023 -0500
+++ b/www/Changelog.html	Sat May 27 14:24:44 2023 -0500
@@ -37,6 +37,15 @@
 </div>
 
 <div class="document">
+<p>2023-05-27  Bob Friesenhahn  &lt;<a class="reference external" href="mailto:bfriesen&#37;&#52;&#48;simple&#46;dallas&#46;tx&#46;us">bfriesen<span>&#64;</span>simple<span>&#46;</span>dallas<span>&#46;</span>tx<span>&#46;</span>us</a>&gt;</p>
+<blockquote>
+<ul class="simple">
+<li><p>coders/tiff.c (ReadTIFFImage): Require that TIFFTAG_EXTRASAMPLES
+be used appropriately to indicate the intention of extra channels.
+Otherwise extra samples beyond what is required by the photometric
+will be ignored.</p></li>
+</ul>
+</blockquote>
 <p>2023-05-25  Bob Friesenhahn  &lt;<a class="reference external" href="mailto:bfriesen&#37;&#52;&#48;simple&#46;dallas&#46;tx&#46;us">bfriesen<span>&#64;</span>simple<span>&#46;</span>dallas<span>&#46;</span>tx<span>&#46;</span>us</a>&gt;</p>
 <blockquote>
 <ul class="simple">