imagemagick/magick/channel.c

998 lines
32 KiB
C
Raw Permalink Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% CCCC H H AAA N N N N EEEEE L %
% C H H A A NN N NN N E L %
% C HHHHH AAAAA N N N N N N EEE L %
% C H H A A N NN N NN E L %
% CCCC H H A A N N N N EEEEE LLLLL %
% %
% %
% MagickCore Image Channel Methods %
% %
% Software Design %
% Cristy %
% December 2003 %
% %
% %
% Copyright 1999-2021 ImageMagick Studio LLC, a non-profit organization %
% dedicated to making software imaging solutions freely available. %
% %
% You may not use this file except in compliance with the License. You may %
% obtain a copy of the License at %
% %
% https://imagemagick.org/script/license.php %
% %
% Unless required by applicable law or agreed to in writing, software %
% distributed under the License is distributed on an "AS IS" BASIS, %
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
% See the License for the specific language governing permissions and %
% limitations under the License. %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
%
*/
/*
Include declarations.
*/
#include "magick/studio.h"
#include "magick/cache-private.h"
#include "magick/channel.h"
#include "magick/color-private.h"
#include "magick/colorspace-private.h"
#include "magick/composite-private.h"
#include "magick/exception-private.h"
#include "magick/enhance.h"
#include "magick/image.h"
#include "magick/list.h"
#include "magick/log.h"
#include "magick/monitor.h"
#include "magick/monitor-private.h"
#include "magick/option.h"
#include "magick/pixel-accessor.h"
#include "magick/resource_.h"
#include "magick/string-private.h"
#include "magick/thread-private.h"
#include "magick/token.h"
#include "magick/utility.h"
#include "magick/version.h"
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% C o m b i n e I m a g e s %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% CombineImages() combines one or more images into a single image. The
% grayscale value of the pixels of each image in the sequence is assigned in
% order to the specified channels of the combined image. The typical
% ordering would be image 1 => Red, 2 => Green, 3 => Blue, etc.
%
% The format of the CombineImages method is:
%
% Image *CombineImages(const Image *image,const ChannelType channel,
% ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport Image *CombineImages(const Image *image,const ChannelType channel,
ExceptionInfo *exception)
{
#define CombineImageTag "Combine/Image"
CacheView
*combine_view;
const Image
*next;
Image
*combine_image;
MagickBooleanType
status;
MagickOffsetType
progress;
ssize_t
y;
/*
Ensure the image are the same size.
*/
assert(image != (const Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickCoreSignature);
for (next=image; next != (Image *) NULL; next=GetNextImageInList(next))
{
if ((next->columns != image->columns) || (next->rows != image->rows))
ThrowImageException(OptionError,"ImagesAreNotTheSameSize");
}
combine_image=CloneImage(image,0,0,MagickTrue,exception);
if (combine_image == (Image *) NULL)
return((Image *) NULL);
if (SetImageStorageClass(combine_image,DirectClass) == MagickFalse)
{
InheritException(exception,&combine_image->exception);
combine_image=DestroyImage(combine_image);
return((Image *) NULL);
}
if (IssRGBCompatibleColorspace(image->colorspace) != MagickFalse)
{
if (fabs(image->gamma-1.0) <= MagickEpsilon)
(void) SetImageColorspace(combine_image,RGBColorspace);
else
(void) SetImageColorspace(combine_image,sRGBColorspace);
}
if ((channel & OpacityChannel) != 0)
combine_image->matte=MagickTrue;
(void) SetImageBackgroundColor(combine_image);
/*
Combine images.
*/
status=MagickTrue;
progress=0;
combine_view=AcquireAuthenticCacheView(combine_image,exception);
for (y=0; y < (ssize_t) combine_image->rows; y++)
{
CacheView
*image_view;
const Image
*next;
PixelPacket
*pixels;
const PixelPacket
*magick_restrict p;
PixelPacket
*magick_restrict q;
ssize_t
x;
if (status == MagickFalse)
continue;
pixels=GetCacheViewAuthenticPixels(combine_view,0,y,combine_image->columns,
1,exception);
if (pixels == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
next=image;
if (((channel & RedChannel) != 0) && (next != (Image *) NULL))
{
image_view=AcquireVirtualCacheView(next,exception);
p=GetCacheViewVirtualPixels(image_view,0,y,next->columns,1,exception);
if (p == (const PixelPacket *) NULL)
continue;
q=pixels;
for (x=0; x < (ssize_t) combine_image->columns; x++)
{
SetPixelRed(q,ClampToQuantum(GetPixelIntensity(image,p)));
p++;
q++;
}
image_view=DestroyCacheView(image_view);
next=GetNextImageInList(next);
}
if (((channel & GreenChannel) != 0) && (next != (Image *) NULL))
{
image_view=AcquireVirtualCacheView(next,exception);
p=GetCacheViewVirtualPixels(image_view,0,y,next->columns,1,exception);
if (p == (const PixelPacket *) NULL)
continue;
q=pixels;
for (x=0; x < (ssize_t) combine_image->columns; x++)
{
SetPixelGreen(q,ClampToQuantum(GetPixelIntensity(image,p)));
p++;
q++;
}
image_view=DestroyCacheView(image_view);
next=GetNextImageInList(next);
}
if (((channel & BlueChannel) != 0) && (next != (Image *) NULL))
{
image_view=AcquireVirtualCacheView(next,exception);
p=GetCacheViewVirtualPixels(image_view,0,y,next->columns,1,exception);
if (p == (const PixelPacket *) NULL)
continue;
q=pixels;
for (x=0; x < (ssize_t) combine_image->columns; x++)
{
SetPixelBlue(q,ClampToQuantum(GetPixelIntensity(image,p)));
p++;
q++;
}
image_view=DestroyCacheView(image_view);
next=GetNextImageInList(next);
}
if (((channel & OpacityChannel) != 0) && (next != (Image *) NULL))
{
image_view=AcquireVirtualCacheView(next,exception);
p=GetCacheViewVirtualPixels(image_view,0,y,next->columns,1,exception);
if (p == (const PixelPacket *) NULL)
continue;
q=pixels;
for (x=0; x < (ssize_t) combine_image->columns; x++)
{
SetPixelAlpha(q,ClampToQuantum(GetPixelIntensity(image,p)));
p++;
q++;
}
image_view=DestroyCacheView(image_view);
next=GetNextImageInList(next);
}
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace) && (next != (Image *) NULL))
{
IndexPacket
*indexes;
image_view=AcquireVirtualCacheView(next,exception);
p=GetCacheViewVirtualPixels(image_view,0,y,next->columns,1,exception);
if (p == (const PixelPacket *) NULL)
continue;
indexes=GetCacheViewAuthenticIndexQueue(combine_view);
for (x=0; x < (ssize_t) combine_image->columns; x++)
{
SetPixelIndex(indexes+x,ClampToQuantum(GetPixelIntensity(image,p)));
p++;
}
image_view=DestroyCacheView(image_view);
next=GetNextImageInList(next);
}
if (SyncCacheViewAuthenticPixels(combine_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp atomic
#endif
progress++;
proceed=SetImageProgress(image,CombineImageTag,progress,
combine_image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
combine_view=DestroyCacheView(combine_view);
if (IsGrayColorspace(combine_image->colorspace) != MagickFalse)
(void) TransformImageColorspace(combine_image,sRGBColorspace);
if (status == MagickFalse)
combine_image=DestroyImage(combine_image);
return(combine_image);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t I m a g e A l p h a C h a n n e l %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetImageAlphaChannel() returns MagickFalse if the image alpha channel is
% not activated. That is, the image is RGB rather than RGBA or CMYK rather
% than CMYKA.
%
% The format of the GetImageAlphaChannel method is:
%
% MagickBooleanType GetImageAlphaChannel(const Image *image)
%
% A description of each parameter follows:
%
% o image: the image.
%
*/
MagickExport MagickBooleanType GetImageAlphaChannel(const Image *image)
{
assert(image != (const Image *) NULL);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
assert(image->signature == MagickCoreSignature);
return(image->matte);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% S e p a r a t e I m a g e C h a n n e l %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% SeparateImageChannel() separates a channel from the image and returns it as
% a grayscale image. A channel is a particular color component of each pixel
% in the image.
%
% The format of the SeparateImageChannel method is:
%
% MagickBooleanType SeparateImageChannel(Image *image,
% const ChannelType channel)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: Identify which channel to extract: RedChannel, GreenChannel,
% BlueChannel, OpacityChannel, CyanChannel, MagentaChannel,
% YellowChannel, or BlackChannel.
%
*/
MagickExport Image *SeparateImage(const Image *image,const ChannelType channel,
ExceptionInfo *exception)
{
Image
*separate_image;
MagickBooleanType
status;
/*
Initialize separate image attributes.
*/
assert(image != (Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickCoreSignature);
separate_image=CloneImage(image,0,0,MagickTrue,exception);
if (separate_image == (Image *) NULL)
return((Image *) NULL);
status=SeparateImageChannel(separate_image,channel);
if (status == MagickFalse)
separate_image=DestroyImage(separate_image);
return(separate_image);
}
MagickExport MagickBooleanType SeparateImageChannel(Image *image,
const ChannelType channel)
{
#define SeparateImageTag "Separate/Image"
CacheView
*image_view;
ExceptionInfo
*exception;
MagickBooleanType
status;
MagickOffsetType
progress;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (SetImageStorageClass(image,DirectClass) == MagickFalse)
return(MagickFalse);
if (channel == GrayChannels)
(void) SetImageAlphaChannel(image,OpaqueAlphaChannel);
/*
Separate image channels.
*/
status=MagickTrue;
progress=0;
exception=(&image->exception);
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
PixelPacket
*magick_restrict q;
ssize_t
x;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
indexes=GetCacheViewAuthenticIndexQueue(image_view);
switch (channel)
{
case RedChannel:
{
for (x=0; x < (ssize_t) image->columns; x++)
{
SetPixelGreen(q,GetPixelRed(q));
SetPixelBlue(q,GetPixelRed(q));
q++;
}
break;
}
case GreenChannel:
{
for (x=0; x < (ssize_t) image->columns; x++)
{
SetPixelRed(q,GetPixelGreen(q));
SetPixelBlue(q,GetPixelGreen(q));
q++;
}
break;
}
case BlueChannel:
{
for (x=0; x < (ssize_t) image->columns; x++)
{
SetPixelRed(q,GetPixelBlue(q));
SetPixelGreen(q,GetPixelBlue(q));
q++;
}
break;
}
case OpacityChannel:
{
for (x=0; x < (ssize_t) image->columns; x++)
{
SetPixelRed(q,GetPixelOpacity(q));
SetPixelGreen(q,GetPixelOpacity(q));
SetPixelBlue(q,GetPixelOpacity(q));
q++;
}
break;
}
case BlackChannel:
{
if ((image->storage_class != PseudoClass) &&
(image->colorspace != CMYKColorspace))
break;
for (x=0; x < (ssize_t) image->columns; x++)
{
SetPixelRed(q,GetPixelIndex(indexes+x));
SetPixelGreen(q,GetPixelIndex(indexes+x));
SetPixelBlue(q,GetPixelIndex(indexes+x));
q++;
}
break;
}
case TrueAlphaChannel:
{
for (x=0; x < (ssize_t) image->columns; x++)
{
SetPixelRed(q,GetPixelAlpha(q));
SetPixelGreen(q,GetPixelAlpha(q));
SetPixelBlue(q,GetPixelAlpha(q));
q++;
}
break;
}
case GrayChannels:
{
for (x=0; x < (ssize_t) image->columns; x++)
{
SetPixelAlpha(q,ClampToQuantum(GetPixelIntensity(image,q)));
q++;
}
break;
}
default:
break;
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp atomic
#endif
progress++;
proceed=SetImageProgress(image,SeparateImageTag,progress,image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
if (channel != GrayChannels)
{
image->matte=MagickFalse;
(void) SetImageColorspace(image,GRAYColorspace);
}
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% S e p a r a t e I m a g e s %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% SeparateImages() returns a separate grayscale image for each channel
% specified.
%
% The format of the SeparateImages method is:
%
% MagickBooleanType SeparateImages(const Image *image,
% const ChannelType channel,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: Identify which channels to extract: RedChannel, GreenChannel,
% BlueChannel, OpacityChannel, CyanChannel, MagentaChannel,
% YellowChannel, or BlackChannel.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport Image *SeparateImages(const Image *image,const ChannelType channel,
ExceptionInfo *exception)
{
Image
*images,
*separate_image;
assert(image != (Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
images=NewImageList();
if ((channel & RedChannel) != 0)
{
separate_image=CloneImage(image,0,0,MagickTrue,exception);
(void) SeparateImageChannel(separate_image,RedChannel);
AppendImageToList(&images,separate_image);
}
if ((channel & GreenChannel) != 0)
{
separate_image=CloneImage(image,0,0,MagickTrue,exception);
(void) SeparateImageChannel(separate_image,GreenChannel);
AppendImageToList(&images,separate_image);
}
if ((channel & BlueChannel) != 0)
{
separate_image=CloneImage(image,0,0,MagickTrue,exception);
(void) SeparateImageChannel(separate_image,BlueChannel);
AppendImageToList(&images,separate_image);
}
if (((channel & BlackChannel) != 0) && (image->colorspace == CMYKColorspace))
{
separate_image=CloneImage(image,0,0,MagickTrue,exception);
(void) SeparateImageChannel(separate_image,BlackChannel);
AppendImageToList(&images,separate_image);
}
if ((channel & AlphaChannel) != 0)
{
separate_image=CloneImage(image,0,0,MagickTrue,exception);
(void) SeparateImageChannel(separate_image,TrueAlphaChannel);
AppendImageToList(&images,separate_image);
}
return(images);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% S e t I m a g e A l p h a C h a n n e l %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% SetImageAlphaChannel() activates, deactivates, resets, or sets the alpha
% channel.
%
% The format of the SetImageAlphaChannel method is:
%
% MagickBooleanType SetImageAlphaChannel(Image *image,
% const AlphaChannelType alpha_type)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o alpha_type: The alpha channel type: ActivateAlphaChannel,
% AssociateAlphaChannel, CopyAlphaChannel, Disassociate,
% DeactivateAlphaChannel, ExtractAlphaChannel, OpaqueAlphaChannel,
% ResetAlphaChannel, SetAlphaChannel, ShapeAlphaChannel, and
% TransparentAlphaChannel.
%
*/
MagickExport MagickBooleanType SetImageAlphaChannel(Image *image,
const AlphaChannelType alpha_type)
{
CacheView
*image_view;
ExceptionInfo
*exception;
MagickBooleanType
status;
ssize_t
y;
assert(image != (Image *) NULL);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
assert(image->signature == MagickCoreSignature);
exception=(&image->exception);
status=MagickTrue;
switch (alpha_type)
{
case ActivateAlphaChannel:
{
image->matte=MagickTrue;
break;
}
case AssociateAlphaChannel:
{
/*
Associate alpha.
*/
status=SetImageStorageClass(image,DirectClass);
if (status == MagickFalse)
break;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
PixelPacket
*magick_restrict q;
ssize_t
x;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
exception);
if (q == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
double
gamma;
gamma=QuantumScale*GetPixelAlpha(q);
SetPixelRed(q,ClampToQuantum(gamma*GetPixelRed(q)));
SetPixelGreen(q,ClampToQuantum(gamma*GetPixelGreen(q)));
SetPixelBlue(q,ClampToQuantum(gamma*GetPixelBlue(q)));
q++;
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
}
image_view=DestroyCacheView(image_view);
image->matte=MagickFalse;
break;
}
case BackgroundAlphaChannel:
{
IndexPacket
index;
MagickBooleanType
status;
MagickPixelPacket
background;
PixelPacket
pixel;
/*
Set transparent pixels to background color.
*/
if (image->matte == MagickFalse)
break;
status=SetImageStorageClass(image,DirectClass);
if (status == MagickFalse)
break;
GetMagickPixelPacket(image,&background);
SetMagickPixelPacket(image,&image->background_color,(const IndexPacket *)
NULL,&background);
if (image->colorspace == CMYKColorspace)
ConvertRGBToCMYK(&background);
index=0;
SetPixelPacket(image,&background,&pixel,&index);
status=MagickTrue;
exception=(&image->exception);
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
PixelPacket
*magick_restrict q;
ssize_t
x;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
exception);
if (q == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
if (q->opacity == TransparentOpacity)
{
SetPixelRed(q,pixel.red);
SetPixelGreen(q,pixel.green);
SetPixelBlue(q,pixel.blue);
}
q++;
}
if (image->colorspace == CMYKColorspace)
{
indexes=GetCacheViewAuthenticIndexQueue(image_view);
for (x=0; x < (ssize_t) image->columns; x++)
SetPixelIndex(indexes+x,index);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
}
image_view=DestroyCacheView(image_view);
return(status);
}
case CopyAlphaChannel:
case ShapeAlphaChannel:
{
/*
Special usage case for SeparateImageChannel(): copy grayscale color to
the alpha channel.
*/
status=SeparateImageChannel(image,GrayChannels);
image->matte=MagickTrue; /* make sure transparency is now on! */
if (alpha_type == ShapeAlphaChannel)
{
MagickPixelPacket
background;
/*
Reset all color channels to background color.
*/
GetMagickPixelPacket(image,&background);
SetMagickPixelPacket(image,&(image->background_color),(IndexPacket *)
NULL,&background);
(void) LevelColorsImage(image,&background,&background,MagickTrue);
}
break;
}
case DeactivateAlphaChannel:
{
image->matte=MagickFalse;
break;
}
case DisassociateAlphaChannel:
{
status=SetImageStorageClass(image,DirectClass);
if (status == MagickFalse)
break;
image->matte=MagickTrue;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
PixelPacket
*magick_restrict q;
ssize_t
x;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
exception);
if (q == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
double
alpha,
gamma;
alpha=QuantumScale*GetPixelAlpha(q);
gamma=PerceptibleReciprocal(alpha);
SetPixelRed(q,ClampToQuantum(gamma*GetPixelRed(q)));
SetPixelGreen(q,ClampToQuantum(gamma*GetPixelGreen(q)));
SetPixelBlue(q,ClampToQuantum(gamma*GetPixelBlue(q)));
q++;
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
}
image_view=DestroyCacheView(image_view);
image->matte=MagickFalse;
break;
}
case ExtractAlphaChannel:
{
status=SeparateImageChannel(image,TrueAlphaChannel);
image->matte=MagickFalse;
break;
}
case RemoveAlphaChannel:
case FlattenAlphaChannel:
{
IndexPacket
index;
MagickPixelPacket
background;
PixelPacket
pixel;
/*
Flatten image pixels over the background pixels.
*/
if (image->matte == MagickFalse)
break;
if (SetImageStorageClass(image,DirectClass) == MagickFalse)
break;
GetMagickPixelPacket(image,&background);
SetMagickPixelPacket(image,&image->background_color,(const IndexPacket *)
NULL,&background);
if (image->colorspace == CMYKColorspace)
ConvertRGBToCMYK(&background);
(void) memset(&pixel,0,sizeof(pixel));
index=0;
SetPixelPacket(image,&background,&pixel,&index);
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
PixelPacket
*magick_restrict q;
ssize_t
x;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
exception);
if (q == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
double
gamma,
opacity;
gamma=1.0-QuantumScale*QuantumScale*q->opacity*pixel.opacity;
opacity=(double) QuantumRange*(1.0-gamma);
gamma=PerceptibleReciprocal(gamma);
q->red=ClampToQuantum(gamma*MagickOver_((MagickRealType) q->red,
(MagickRealType) q->opacity,(MagickRealType) pixel.red,
(MagickRealType) pixel.opacity));
q->green=ClampToQuantum(gamma*MagickOver_((MagickRealType) q->green,
(MagickRealType) q->opacity,(MagickRealType) pixel.green,
(MagickRealType) pixel.opacity));
q->blue=ClampToQuantum(gamma*MagickOver_((MagickRealType) q->blue,
(MagickRealType) q->opacity,(MagickRealType) pixel.blue,
(MagickRealType) pixel.opacity));
q->opacity=ClampToQuantum(opacity);
q++;
}
if (image->colorspace == CMYKColorspace)
{
indexes=GetCacheViewAuthenticIndexQueue(image_view);
for (x=0; x < (ssize_t) image->columns; x++)
SetPixelIndex(indexes+x,index);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
}
image_view=DestroyCacheView(image_view);
return(status);
}
case ResetAlphaChannel: /* deprecated */
case OpaqueAlphaChannel:
{
status=SetImageOpacity(image,OpaqueOpacity);
break;
}
case SetAlphaChannel:
{
if (image->matte == MagickFalse)
status=SetImageOpacity(image,OpaqueOpacity);
break;
}
case TransparentAlphaChannel:
{
status=SetImageOpacity(image,TransparentOpacity);
break;
}
case UndefinedAlphaChannel:
break;
}
if (status == MagickFalse)
return(status);
return(SyncImagePixelCache(image,&image->exception));
}