Fix 3-3-2 palette generation to work with Q16 and Q32 builds.

diff --git a/ChangeLog b/ChangeLog
index 4684e25d0704ff08e411c2f66a8a9984de4eeb90..25fea8d404b5c9b4a1c37b1aa65a4d23302464e1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2011-02-22  6.6.8-0 Glenn Randers-Pehrson <glennrp@image...>
+  * Fix scaling of new color-reduction method in the PNG encoder (16-bit
+    images were scaled down to 0 or 1, or nearly black).
+
 2011-02-25  6.6.7-10 Cristy  <quetzlzacatenango@image...>
   * New version 6.6.7-10.
 
@@ -20,8 +24,8 @@
   * Add a check whether the PNG "cheap transparency" criteria are met.  That
     is, there is a single transparent color, no semitransparent colors, and
     no opaque color that has the same RGB components as the transparent
-    color.  If they aren't, a color that is transparent in one pixel
-    and opaque in another would always be rendered as transparent. (reference
+    color.  If those aren't met, a color that is transparent in one pixel
+    and opaque in another would always be rendered as transparent (reference
     http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=18167).
 
 2011-02-22  6.6.7-9 Cristy  <quetzlzacatenango@image...>
@@ -93,7 +97,7 @@
     of CPU time. (reference
     http://www.imagemagick.org/discourse-server/viewtopic.php?f=2&t=17799).
   * Sometimes black was still written as transparent, when the PNG
-    encoder received an image with image->matte==true no transparent
+    encoder received an image with image->matte==true but no transparent
     pixels were present. (reference
     http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=17913);
 

diff --git a/coders/png.c b/coders/png.c
index 38e180f6cc4d5585de068934d53a70f706de0402..1275212faf63e1b2d9df4de44e1ce9be17fa0b7a 100644 (file)
--- a/coders/png.c
+++ b/coders/png.c
@@ -6996,6 +6996,17 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
      * we need to check for bogus non-opaque values, at least.
      */
 
+#if (MAGICKCORE_QUANTUM_DEPTH == 8)
+#  define PNGK 0 /* Shift */
+#  define PNGM 1 /* Scale */
+#elif (MAGICKCORE_QUANTUM_DEPTH == 16)
+#  define PNGK 8
+#  define PNGM 0x0101
+#else
+#  define PNGK 24
+#  define PNGM 0x01010101
+#endif
+
    ExceptionInfo
      *exception;
 
@@ -7497,48 +7508,25 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
      * background color to the 3-3-2 palette.
      */
 
-
     if (image_colors == 0 || image_colors > 256)
       {
         if (logging != MagickFalse)
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                "    Quantizing the background color to 3-3-2");
 
-    if (image->depth == 8)
-      {
-        image->background_color.red=
-              (image->background_color.red & 0xe0)       |
-              ((image->background_color.red & 0xe0) >> 3) |
-              ((image->background_color.red & 0xc0) >> 6);
-        image->background_color.green=
-              (image->background_color.green & 0xe0)       |
-              ((image->background_color.green & 0xe0) >> 3) |
-              ((image->background_color.green & 0xc0) >> 6);
-        image->background_color.blue=
-              (image->background_color.blue & 0xc0)       |
-              ((image->background_color.blue & 0xc0) >> 2) |
-              ((image->background_color.blue & 0xc0) >> 4) |
-              ((image->background_color.blue & 0xc0) >> 6);
-      }
-#if (MAGICKCORE_QUANTUM_DEPTH >= 16)
-    else
-      {
         image->background_color.red=
-             (((image->background_color.red & 0xe0) >> 8) |
-              ((image->background_color.red & 0xe0) >> 11) |
-              ((image->background_color.red & 0xc0) >> 14))*0x0101;
+             ((((image->background_color.red >> PNGK) & 0xe0)     )  |
+              (((image->background_color.red >> PNGK) & 0xe0) >> 3)  |
+              (((image->background_color.red >> PNGK) & 0xc0) >> 6)) * PNGM;
         image->background_color.green=
-            (((image->background_color.green & 0xe0) >> 8) |
-              ((image->background_color.green & 0xe0) >> 11) |
-              ((image->background_color.green & 0xc0) >> 14))*0x0101;
+             ((((image->background_color.green >> PNGK) & 0xe0)     )  |
+              (((image->background_color.green >> PNGK) & 0xe0) >> 3)  |
+              (((image->background_color.green >> PNGK) & 0xc0) >> 6)) * PNGM;
         image->background_color.blue=
-             (((image->background_color.blue & 0xc0)>>  8) |
-              ((image->background_color.blue & 0xc0) >> 10) |
-              ((image->background_color.blue & 0xc0) >> 12) |
-              ((image->background_color.blue & 0xc0) >> 14))*0x0101;
-      }
-#endif
-/* To do: Add Q32 case */
+             ((((image->background_color.blue >> PNGK) & 0xc0)     )  |
+              (((image->background_color.blue >> PNGK) & 0xc0) >> 2)  |
+              (((image->background_color.blue >> PNGK) & 0xc0) >> 4)  |
+              (((image->background_color.blue >> PNGK) & 0xc0) >> 6)) * PNGM;
 
         if (logging != MagickFalse)
           (void) LogMagickEvent(CoderEvent,GetMagickModule(),
@@ -7556,35 +7544,20 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
 
             for (x=0; x < (ssize_t) image->columns; x++)
             {
-              if (image->depth == 8)
-              {
-               r->red=  (r->red & 0xe0)        |
-                        ((r->red & 0xe0) >> 3) |
-                        ((r->red & 0xc0) >> 6);
-               r->green=(r->green & 0xe0)        |
-                        ((r->green & 0xe0) >> 3) |
-                        ((r->green & 0xc0) >> 6);
-               r->blue= (r->blue & 0xc0)        |
-                        ((r->blue & 0xc0) >> 2) |
-                        ((r->blue & 0xc0) >> 4) |
-                        ((r->blue & 0xc0) >> 6);
-               }
-#if (MAGICKCORE_QUANTUM_DEPTH >= 16)
-             else
-               {
-               r->red= (((r->red & 0xe0) >> 8) |
-                       ((r->red & 0xe0) >> 11) |
-                       ((r->red & 0xc0) >> 14))*0x0101;
-               r->green=(((r->green & 0xe0) >> 8) |
-                       ((r->green & 0xe0) >> 11) |
-                       ((r->green & 0xc0) >> 14))*0x0101;
-               r->blue=(((r->blue & 0xc0)>>  8) |
-                       ((r->blue & 0xc0) >> 10) |
-                       ((r->blue & 0xc0) >> 12) |
-                       ((r->blue & 0xc0) >> 14))*0x0101;
-               }
-#endif
-                r++;
+              r->red=
+                   ((((r->red >> PNGK) & 0xe0)     )  |
+                    (((r->red >> PNGK) & 0xe0) >> 3)  |
+                    (((r->red >> PNGK) & 0xc0) >> 6)) * PNGM;
+              r->green=
+                   ((((r->green >> PNGK) & 0xe0)     )  |
+                    (((r->green >> PNGK) & 0xe0) >> 3)  |
+                    (((r->green >> PNGK) & 0xc0) >> 6)) * PNGM;
+              r->blue=
+                   ((((r->blue >> PNGK) & 0xc0)     )  |
+                    (((r->blue >> PNGK) & 0xc0) >> 2)  |
+                    (((r->blue >> PNGK) & 0xc0) >> 4)  |
+                    (((r->blue >> PNGK) & 0xc0) >> 6)) * PNGM;
+              r++;
             }
     
             if (SyncAuthenticPixels(image,exception) == MagickFalse)
@@ -7600,40 +7573,19 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
               "    Quantizing the colormap to 3-3-2");
           for (i=0; i<image_colors; i++)
           {
-            if (image->depth == 8)
-             {
-             image->colormap[i].red=
-                     (image->colormap[i].red & 0xe0)        |
-                     ((image->colormap[i].red & 0xe0) >> 3) |
-                     ((image->colormap[i].red & 0xc0) >> 6);
-             image->colormap[i].green=
-                     (image->colormap[i].green & 0xe0)        |
-                     ((image->colormap[i].green & 0xe0) >> 3) |
-                     ((image->colormap[i].green & 0xc0) >> 6);
-             image->colormap[i].blue=
-                     (image->colormap[i].blue & 0xc0)        |
-                     ((image->colormap[i].blue & 0xc0) >> 2) |
-                     ((image->colormap[i].blue & 0xc0) >> 4) |
-                     ((image->colormap[i].blue & 0xc0) >> 6);
-             }
-#if (MAGICKCORE_QUANTUM_DEPTH >= 16)
-          else
-             {
-             image->colormap[i].red=
-                     (((image->colormap[i].red & 0xe0) >> 8) |
-                     ((image->colormap[i].red & 0xe0) >> 11) |
-                     ((image->colormap[i].red & 0xc0) >> 14))*0x0101;
-             image->colormap[i].green=
-                     (((image->colormap[i].green & 0xe0) >> 8) |
-                     ((image->colormap[i].green & 0xe0) >> 11) |
-                     ((image->colormap[i].green & 0xc0) >> 14))*0x0101;
-             image->colormap[i].blue=
-                     (((image->colormap[i].blue & 0xc0)>>  8) |
-                     ((image->colormap[i].blue & 0xc0) >> 10) |
-                     ((image->colormap[i].blue & 0xc0) >> 12) |
-                     ((image->colormap[i].blue & 0xc0) >> 14))*0x0101;
-             }
-#endif
+              image->colormap[i].red=
+                   ((((image->colormap[i].red >> PNGK) & 0xe0)     )  |
+                    (((image->colormap[i].red >> PNGK) & 0xe0) >> 3)  |
+                    (((image->colormap[i].red >> PNGK) & 0xc0) >> 6)) * PNGM;
+              image->colormap[i].green=
+                   ((((image->colormap[i].green >> PNGK) & 0xe0)     )  |
+                    (((image->colormap[i].green >> PNGK) & 0xe0) >> 3)  |
+                    (((image->colormap[i].green >> PNGK) & 0xc0) >> 6)) * PNGM;
+              image->colormap[i].blue=
+                   ((((image->colormap[i].blue >> PNGK) & 0xc0)     )  |
+                    (((image->colormap[i].blue >> PNGK) & 0xc0) >> 2)  |
+                    (((image->colormap[i].blue >> PNGK) & 0xc0) >> 4)  |
+                    (((image->colormap[i].blue >> PNGK) & 0xc0) >> 6)) * PNGM;
           }
       }
       continue;
@@ -7754,6 +7706,23 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
   mng_info->IsPalette=image->storage_class == PseudoClass &&
     image_colors <= 256 && image->colormap != NULL;
 
+  if ((mng_info->write_png_colortype == 4 || mng_info->write_png8) &&
+     (image->colors == 0 || image->colormap == NULL))
+    {
+      (void) ThrowMagickException(&image->exception,
+          GetMagickModule(),CoderWarning,
+          "Cannot write PNG8 or color-type 3; colormap is NULL",
+          "`%s'",image->filename);
+      if (mng_info->need_blob != MagickFalse)
+          (void) CloseBlob(image);
+      image_info=DestroyImageInfo(image_info);
+      image=DestroyImage(image);
+#if defined(PNG_SETJMP_NOT_THREAD_SAFE)
+      UnlockSemaphoreInfo(ping_semaphore);
+#endif
+      return(MagickFalse);
+    }
+
   /*
     Allocate the PNG structures
   */
@@ -7800,13 +7769,6 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
       image=DestroyImage(image);
       return(MagickFalse);
     }
-
-  if ((mng_info->write_png_colortype == 4 || mng_info->write_png8) &&
-     (image->colors == 0 || image->colormap == NULL))
-    {
-      png_error(ping, "Cannot write PNG8 or color-type 3; colormap is NULL");
-    }
-
   /*
     Prepare PNG for writing.
   */