revised LosslessReduce() to LosslessReduceOK() to simply return a flag

diff --git a/coders/png.c b/coders/png.c
index 8ebcb367737cd2bca3ebf74f18898ef4b80b5537..14a59016f294719a87c02d418f555aa63f083e36 100644 (file)
--- a/coders/png.c
+++ b/coders/png.c
@@ -481,7 +481,7 @@ static MagickBooleanType
 
 #if (MAGICKCORE_QUANTUM_DEPTH >= 16)
 static MagickBooleanType
-  LosslessReduceDepth(Image *image)
+  LosslessReduceDepthOK(Image *image)
 {
     MagickBooleanType
       ok_to_reduce=MagickFalse;
@@ -507,18 +507,12 @@ static MagickBooleanType
 
         ok_to_reduce=
           (((((size_t) image->background_color.red >> 8) & 0xff)
-             == ((size_t) image->background_color.red & 0xff)) &&
+          == ((size_t) image->background_color.red & 0xff)) &&
            ((((size_t) image->background_color.green >> 8) & 0xff)
-             == ((size_t) image->background_color.green & 0xff)) &&
+          == ((size_t) image->background_color.green & 0xff)) &&
            ((((size_t) image->background_color.blue >> 8) & 0xff)
-             == ((size_t) image->background_color.blue & 0xff)) &&
-           ((((size_t) image->background_color.opacity >> 8) & 0xff)
-             == ((size_t) image->background_color.opacity & 0xff))) ?
-           MagickTrue : MagickFalse;
-
-        if (ok_to_reduce != MagickFalse)
-          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-                 "    OK to reduce background bit depth to 8");
+          == ((size_t) image->background_color.blue & 0xff))) ? MagickTrue :
+          MagickFalse;
 
         if (ok_to_reduce != MagickFalse && image->storage_class == PseudoClass)
           {
@@ -526,23 +520,19 @@ static MagickBooleanType
 
             for (indx=0; indx < (ssize_t) image->colors; indx++)
               {
-                ok_to_reduce=
-                  (((((size_t) image->colormap[indx].red >> 8) & 0xff)
-                     == ((size_t) image->colormap[indx].red & 0xff)) &&
+                ok_to_reduce=(((((size_t) image->colormap[indx].red >>
+                    8) & 0xff)
+                  == ((size_t) image->colormap[indx].red & 0xff)) &&
                   ((((size_t) image->colormap[indx].green >> 8) & 0xff)
-                     == ((size_t) image->colormap[indx].green & 0xff)) &&
+                  == ((size_t) image->colormap[indx].green & 0xff)) &&
                   ((((size_t) image->colormap[indx].blue >> 8) & 0xff)
-                     == ((size_t) image->colormap[indx].blue & 0xff)) &&
+                  == ((size_t) image->colormap[indx].blue & 0xff)) &&
                   ((((size_t) image->colormap[indx].opacity >> 8) & 0xff)
-                     == ((size_t) image->colormap[indx].opacity & 0xff))) ?
+                  == ((size_t) image->colormap[indx].opacity & 0xff))) ?
                   MagickTrue : MagickFalse;
-
                 if (ok_to_reduce == MagickFalse)
                   break;
               }
-            if (ok_to_reduce != MagickFalse)
-              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-                     "    OK to reduce colormap bit depth to 8");
           }
 
         if ((ok_to_reduce != MagickFalse) &&
@@ -566,40 +556,31 @@ static MagickBooleanType
 
               for (x=(ssize_t) image->columns-1; x >= 0; x--)
               {
-                ok_to_reduce=(
-                  ((((size_t) p->red >> 8) & 0xff) ==
-                   ((size_t) p->red & 0xff)) &&
+                ok_to_reduce=((
+                  (((size_t) p->red >> 8) & 0xff) ==
+                  ((size_t) p->red & 0xff)) &&
                   ((((size_t) p->green >> 8) & 0xff) ==
-                   ((size_t) p->green & 0xff)) &&
+                  ((size_t) p->green & 0xff)) &&
                   ((((size_t) p->blue >> 8) & 0xff) ==
-                   ((size_t) p->blue & 0xff)) &&
-                  ((image->matte == MagickFalse ||
-                   (((size_t) p->opacity >> 8) & 0xff) ==
-                   ((size_t) p->opacity & 0xff)))) ? MagickTrue : MagickFalse;
+                  ((size_t) p->blue & 0xff)) &&
+                  (((!image->matte ||
+                  (((size_t) p->opacity >> 8) & 0xff) ==
+                  ((size_t) p->opacity & 0xff))))) ? MagickTrue : MagickFalse;
 
                 if (ok_to_reduce == MagickFalse)
                   break;
 
                 p++;
               }
-
-              if (ok_to_reduce == MagickFalse)
+              if (x >= 0)
                 break;
             }
-
-          if (ok_to_reduce != MagickFalse)
-            {
-              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-                   "    OK to reduce all pixels bit depth to 8");
-            }
           }
 
         if (ok_to_reduce != MagickFalse)
           {
-            image->depth=8;
-
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-                "    Reducing PNG bit depth to 8 without loss of info");
+                "  OK to reduce PNG bit depth to 8 without loss of info");
           }
       }
 
@@ -703,16 +684,13 @@ static MagickBooleanType ImageIsGray(Image *image)
       for (i=0; i < (ssize_t) image->colors; i++)
         if (IsGray(image->colormap+i) == MagickFalse)
           return(MagickFalse);
-
       return(MagickTrue);
     }
   for (y=0; y < (ssize_t) image->rows; y++)
   {
     p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
-
     if (p == (const PixelPacket *) NULL)
       return(MagickFalse);
-
     for (x=(ssize_t) image->columns-1; x >= 0; x--)
     {
        if (IsGray(p) == MagickFalse)
@@ -5942,10 +5920,10 @@ static Image *ReadMNGImage(const ImageInfo *image_info,ExceptionInfo *exception)
       }
 
 #if (MAGICKCORE_QUANTUM_DEPTH >= 16)
-      (void) LosslessReduceDepth(image);
+      if (LosslessReduceDepthOK(image) != MagickFalse)
+         image->depth = 8;
 #endif
 
-
       GetImageException(image,exception);
       if (image_info->number_scenes != 0)
         {
@@ -7104,10 +7082,17 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
   ping_have_pHYs=MagickFalse;
   ping_have_tRNS=MagickFalse;
 
-
   if (image->colorspace != RGBColorspace)
     (void) TransformImageColorspace(image,RGBColorspace);
 
+#if (MAGICKCORE_QUANTUM_DEPTH >= 16)
+  if (mng_info->write_png_colortype != 16)
+    if (LosslessReduceDepthOK(image) != MagickFalse)
+      image->depth = 8;
+#endif
+
+  image_depth=image->depth;
+
   /*
     Sometimes we get PseudoClass images whose RGB values don't match
     the colors in the colormap.  This code syncs the RGB values.
@@ -7115,18 +7100,13 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
   if (image->taint && image->storage_class == PseudoClass)
      (void) SyncImage(image);
 
-#if (MAGICKCORE_QUANTUM_DEPTH >= 16)
-  (void) LosslessReduceDepth(image);
-#endif
-
   quantum_info = (QuantumInfo *) NULL;
   number_colors=0;
   image_colors=image->colors;
-  image_depth=image->depth;
   image_matte=image->matte;
 
 #ifdef PNG_BUILD_PALETTE
-
+  
   if (((mng_info->write_png_colortype-1) == PNG_COLOR_TYPE_PALETTE) ||
       (mng_info->write_png_colortype == 0 && image->depth <= 8))
     {
@@ -7236,10 +7216,11 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
         "    image_matte=%.20g",(double) image->matte);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-        "    image_depth=%.20g",(double) image->depth);
+        "    image->depth=%.20g",(double) image->depth);
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-        "    requested PNG image_depth=%.20g",(double) image->depth);
+        "    Tentative ping_bit_depth=%.20g",(double) image_depth);
     }
+
   save_image_depth=image_depth;
   ping_bit_depth=(png_byte) save_image_depth;
 
@@ -7306,7 +7287,10 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
 
   if (logging != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-         "    Setting up bKGD chunk");
+         "    Setting up bKGd chunk");
+  if (logging != MagickFalse)
+     (void) LogMagickEvent(CoderEvent,GetMagickModule(),
+         "    ping_bit_depth=%d",ping_bit_depth);
 
   ping_have_bKGD = MagickTrue;
 
@@ -7493,7 +7477,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
         {
           if (logging != MagickFalse)
              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-             "Selecting PNG colortype");
+             "  Selecting PNG colortype");
 
           ping_color_type=(png_byte) ((matte == MagickTrue)?
           PNG_COLOR_TYPE_RGB_ALPHA:PNG_COLOR_TYPE_RGB);
@@ -7530,13 +7514,8 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
         }
 
       if (logging != MagickFalse)
-      {
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-         "Selected PNG colortype=%d",ping_color_type);
-
-         (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-         "   image->depth=%d (%d)",(int) image->depth, (int) image_depth);
-      }
+         "    Selected PNG colortype=%d",ping_color_type);
 
       if (ping_bit_depth < 8)
         {
@@ -7559,6 +7538,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
                 }
             }
         }
+
       if (ping_color_type == PNG_COLOR_TYPE_PALETTE)
         {
            size_t one = 1;
@@ -7621,6 +7601,9 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
         "    image_depth: %.20g",(double) image_depth);
 
+      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
+        "    image->depth: %.20g",(double) image->depth);
+
       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
         "    ping_bit_depth: %.20g",(double) ping_bit_depth);
     }
@@ -7665,7 +7648,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
           p++;
         }
 
-        if (x >= 0)
+        if (x != 0)
           break;
       }
 
@@ -7775,6 +7758,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
             }
         }
     }
+
     matte=image_matte;
 
     if (ping_have_tRNS != MagickFalse)
@@ -7846,7 +7830,6 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
                    else if ((intensity & 0x01) != ((intensity & 0x02) >> 1))
                      depth_1_ok=MagickFalse;
                 }
-
                 if (depth_1_ok && mng_info->write_png_depth <= 1)
                   ping_bit_depth=1;
 
@@ -7887,7 +7870,6 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
                 if (CompressColormapTransFirst(image) == MagickFalse)
                    ThrowWriterException(ResourceLimitError,
                                         "MemoryAllocationFailed");
-
                 number_colors=image->colors;
                 image_colors=number_colors;
 
@@ -8184,18 +8166,20 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
       base_filter;
 
     if ((quality % 10) > 5)
-        base_filter=PNG_ALL_FILTERS;
+      base_filter=PNG_ALL_FILTERS;
 
-    else if ((quality % 10) != 5)
+    else
+      if ((quality % 10) != 5)
         base_filter=(int) quality % 10;
 
-    else if (((int) ping_color_type == PNG_COLOR_TYPE_GRAY) ||
+      else
+        if (((int) ping_color_type == PNG_COLOR_TYPE_GRAY) ||
             ((int) ping_color_type == PNG_COLOR_TYPE_PALETTE) ||
             (quality < 50))
-        base_filter=PNG_NO_FILTERS;
+          base_filter=PNG_NO_FILTERS;
 
-    else
-        base_filter=PNG_ALL_FILTERS;
+        else
+          base_filter=PNG_ALL_FILTERS;
 
     if (logging != MagickFalse)
       {
@@ -8344,7 +8328,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
         "Cannot write image with defined PNG:bit-depth or PNG:color-type.");
     }
 
-  if (image_matte != MagickFalse && image->matte == MagickFalse)
+  if (image_matte && !image->matte)
     {
       /* Add an opaque matte channel */
       image->matte = MagickTrue;
@@ -8377,7 +8361,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
 
       if (logging)
         {
-          for (i=0; i< number_colors; i++)
+          for (i=0; i< (ssize_t) number_colors; i++)
           {
             if (ping_num_trans != 0)
               (void) LogMagickEvent(CoderEvent,GetMagickModule(),
@@ -8517,7 +8501,6 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
       (void) LogMagickEvent(CoderEvent,GetMagickModule(),
         "    Allocating %.20g bytes of memory for pixels",(double) rowbytes);
     }
-
   png_pixels=(unsigned char *) AcquireQuantumMemory(rowbytes,
     sizeof(*png_pixels));
 
@@ -8769,10 +8752,15 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
               (void) ExportQuantumPixels(image,(const CacheView *) NULL,
                 quantum_info,IndexQuantum,png_pixels,&image->exception);
 
-            if (logging && y <= 2)
-              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
-                  "  Writing row of pixels (4)");
+              if (logging && y <= 2)
+              {
+                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
+                    "  Writing row of pixels (4)");
 
+                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
+                    "  png_pixels[0]=%d,png_pixels[1]=%d",
+                    (int)png_pixels[0],(int)png_pixels[1]);
+              }
             png_write_row(ping,png_pixels);
           }
         }