support -alpha remove-opaque option

ImageMagick · Dec 31, 2023 · 0ce621f · 0ce621f
1 parent 6c76d71
commit 0ce621f
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Showing 4 changed files with 66 additions and 20 deletions.
diff --git a/MagickCore/channel.c b/MagickCore/channel.c
@@ -1261,6 +1261,49 @@ MagickExport MagickBooleanType SetImageAlphaChannel(Image *image,
       image->alpha_trait=image->background_color.alpha_trait;
       break;
     }
+    case RemoveOpaqueAlphaChannel:
+    {
+      MagickBooleanType
+        opaque = MagickTrue;
+
+      /*
+        Remove opaque alpha channel.
+      */
+      if ((image->alpha_trait & BlendPixelTrait) == 0)
+        break;
+      image_view=AcquireVirtualCacheView(image,exception);
+#if defined(MAGICKCORE_OPENMP_SUPPORT)
+      #pragma omp parallel for schedule(static) shared(opaque,status) \
+        magick_number_threads(image,image,image->rows,1)
+#endif
+      for (y=0; y < (ssize_t) image->rows; y++)
+      {
+        const Quantum
+          *magick_restrict p;
+
+        ssize_t
+          x;
+
+        if ((status == MagickFalse) || (opaque == MagickFalse))
+          continue;
+        p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
+        if (p == (const Quantum *) NULL)
+          {
+            status=MagickFalse;
+            continue;
+          }
+        for (x=0; x < (ssize_t) image->columns; x++)
+        {
+          if (GetPixelAlpha(image,p) != OpaqueAlpha)
+            opaque=MagickFalse;
+          p+=GetPixelChannels(image);
+        }
+      }
+      image_view=DestroyCacheView(image_view);
+      if (opaque != MagickFalse)
+        image->alpha_trait=UndefinedPixelTrait;
+      break;
+    }
     case SetAlphaChannel:
     {
       if ((image->alpha_trait & BlendPixelTrait) == 0)

diff --git a/MagickCore/channel.h b/MagickCore/channel.h
@@ -24,6 +24,27 @@
 extern "C" {
 #endif
 
+typedef enum
+{
+  UndefinedAlphaChannel,
+  ActivateAlphaChannel,
+  AssociateAlphaChannel,
+  BackgroundAlphaChannel,
+  CopyAlphaChannel,
+  DeactivateAlphaChannel,
+  DiscreteAlphaChannel,
+  DisassociateAlphaChannel,
+  ExtractAlphaChannel,
+  OffAlphaChannel,
+  OnAlphaChannel,
+  OpaqueAlphaChannel,
+  RemoveAlphaChannel,
+  SetAlphaChannel,
+  ShapeAlphaChannel,
+  TransparentAlphaChannel,
+  RemoveOpaqueAlphaChannel
+} AlphaChannelOption;
+
 extern MagickExport Image
   *ChannelFxImage(const Image *,const char *,ExceptionInfo *),
   *CombineImages(const Image *,const ColorspaceType,ExceptionInfo *),

diff --git a/MagickCore/image.h b/MagickCore/image.h
@@ -25,26 +25,6 @@ extern "C" {
 #define OpaqueAlpha  ((Quantum) QuantumRange)
 #define TransparentAlpha  ((Quantum) 0)
 
-typedef enum
-{
-  UndefinedAlphaChannel,
-  ActivateAlphaChannel,
-  AssociateAlphaChannel,
-  BackgroundAlphaChannel,
-  CopyAlphaChannel,
-  DeactivateAlphaChannel,
-  DiscreteAlphaChannel,
-  DisassociateAlphaChannel,
-  ExtractAlphaChannel,
-  OffAlphaChannel,
-  OnAlphaChannel,
-  OpaqueAlphaChannel,
-  RemoveAlphaChannel,
-  SetAlphaChannel,
-  ShapeAlphaChannel,
-  TransparentAlphaChannel
-} AlphaChannelOption;
-
 typedef enum
 {
   UndefinedType,

diff --git a/MagickCore/option.c b/MagickCore/option.c
@@ -43,6 +43,7 @@
 #include "MagickCore/studio.h"
 #include "MagickCore/artifact.h"
 #include "MagickCore/cache.h"
+#include "MagickCore/channel.h"
 #include "MagickCore/color.h"
 #include "MagickCore/compare.h"
 #include "MagickCore/constitute.h"
@@ -115,6 +116,7 @@ static const OptionInfo
     { "On", OnAlphaChannel, UndefinedOptionFlag, MagickFalse },
     { "Opaque", OpaqueAlphaChannel, UndefinedOptionFlag, MagickFalse },
     { "Remove", RemoveAlphaChannel, UndefinedOptionFlag, MagickFalse },
+    { "RemoveOpaque", RemoveOpaqueAlphaChannel, UndefinedOptionFlag, MagickFalse },
     { "Set", SetAlphaChannel, UndefinedOptionFlag, MagickFalse },
     { "Shape", ShapeAlphaChannel, UndefinedOptionFlag, MagickFalse },
     { "Reset", SetAlphaChannel, DeprecateOptionFlag, MagickTrue },