/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% TTTTT H H RRRR EEEEE SSSSS H H OOO L DDDD %
% T H H R R E SS H H O O L D D %
% T HHHHH RRRR EEE SSS HHHHH O O L D D %
% T H H R R E SS H H O O L D D %
% T H H R R EEEEE SSSSS H H OOO LLLLL DDDD %
% %
% %
% MagickCore Image Threshold Methods %
% %
% Software Design %
% Cristy %
% October 1996 %
% %
% %
% Copyright 1999-2016 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 %
% %
% http://www.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 "MagickCore/studio.h"
#include "MagickCore/property.h"
#include "MagickCore/blob.h"
#include "MagickCore/cache-view.h"
#include "MagickCore/color.h"
#include "MagickCore/color-private.h"
#include "MagickCore/colormap.h"
#include "MagickCore/colorspace.h"
#include "MagickCore/colorspace-private.h"
#include "MagickCore/configure.h"
#include "MagickCore/constitute.h"
#include "MagickCore/decorate.h"
#include "MagickCore/draw.h"
#include "MagickCore/enhance.h"
#include "MagickCore/exception.h"
#include "MagickCore/exception-private.h"
#include "MagickCore/effect.h"
#include "MagickCore/fx.h"
#include "MagickCore/gem.h"
#include "MagickCore/geometry.h"
#include "MagickCore/image-private.h"
#include "MagickCore/list.h"
#include "MagickCore/log.h"
#include "MagickCore/memory_.h"
#include "MagickCore/monitor.h"
#include "MagickCore/monitor-private.h"
#include "MagickCore/montage.h"
#include "MagickCore/option.h"
#include "MagickCore/pixel-accessor.h"
#include "MagickCore/pixel-private.h"
#include "MagickCore/quantize.h"
#include "MagickCore/quantum.h"
#include "MagickCore/random_.h"
#include "MagickCore/random-private.h"
#include "MagickCore/resize.h"
#include "MagickCore/resource_.h"
#include "MagickCore/segment.h"
#include "MagickCore/shear.h"
#include "MagickCore/signature-private.h"
#include "MagickCore/string_.h"
#include "MagickCore/string-private.h"
#include "MagickCore/thread-private.h"
#include "MagickCore/threshold.h"
#include "MagickCore/token.h"
#include "MagickCore/transform.h"
#include "MagickCore/xml-tree.h"
#include "MagickCore/xml-tree-private.h"
/*
Define declarations.
*/
#define ThresholdsFilename "thresholds.xml"
/*
Typedef declarations.
*/
struct _ThresholdMap
{
char
*map_id,
*description;
size_t
width,
height;
ssize_t
divisor,
*levels;
};
/*
Static declarations.
*/
static const char
*MinimalThresholdMap =
"<?xml version=\"1.0\"?>"
"<thresholds>"
" <threshold map=\"threshold\" alias=\"1x1\">"
" <description>Threshold 1x1 (non-dither)</description>"
" <levels width=\"1\" height=\"1\" divisor=\"2\">"
" 1"
" </levels>"
" </threshold>"
" <threshold map=\"checks\" alias=\"2x1\">"
" <description>Checkerboard 2x1 (dither)</description>"
" <levels width=\"2\" height=\"2\" divisor=\"3\">"
" 1 2"
" 2 1"
" </levels>"
" </threshold>"
"</thresholds>";
/*
Forward declarations.
*/
static ThresholdMap
*GetThresholdMapFile(const char *,const char *,const char *,ExceptionInfo *);
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% A d a p t i v e T h r e s h o l d I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% AdaptiveThresholdImage() selects an individual threshold for each pixel
% based on the range of intensity values in its local neighborhood. This
% allows for thresholding of an image whose global intensity histogram
% doesn't contain distinctive peaks.
%
% The format of the AdaptiveThresholdImage method is:
%
% Image *AdaptiveThresholdImage(const Image *image,const size_t width,
% const size_t height,const double bias,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o width: the width of the local neighborhood.
%
% o height: the height of the local neighborhood.
%
% o bias: the mean bias.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport Image *AdaptiveThresholdImage(const Image *image,
const size_t width,const size_t height,const double bias,
ExceptionInfo *exception)
{
#define AdaptiveThresholdImageTag "AdaptiveThreshold/Image"
CacheView
*image_view,
*threshold_view;
Image
*threshold_image;
MagickBooleanType
status;
MagickOffsetType
progress;
MagickSizeType
number_pixels;
ssize_t
y;
/*
Initialize threshold 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);
threshold_image=CloneImage(image,image->columns,image->rows,MagickTrue,
exception);
if (threshold_image == (Image *) NULL)
return((Image *) NULL);
status=SetImageStorageClass(threshold_image,DirectClass,exception);
if (status == MagickFalse)
{
threshold_image=DestroyImage(threshold_image);
return((Image *) NULL);
}
/*
Threshold image.
*/
status=MagickTrue;
progress=0;
number_pixels=(MagickSizeType) width*height;
image_view=AcquireVirtualCacheView(image,exception);
threshold_view=AcquireAuthenticCacheView(threshold_image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(progress,status) \
magick_threads(image,threshold_image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
double
channel_bias[MaxPixelChannels],
channel_sum[MaxPixelChannels];
register const Quantum
*magick_restrict p,
*magick_restrict pixels;
register Quantum
*magick_restrict q;
register ssize_t
i,
x;
ssize_t
center,
u,
v;
if (status == MagickFalse)
continue;
p=GetCacheViewVirtualPixels(image_view,-((ssize_t) width/2L),y-(ssize_t)
(height/2L),image->columns+width,height,exception);
q=QueueCacheViewAuthenticPixels(threshold_view,0,y,threshold_image->columns,
1,exception);
if ((p == (const Quantum *) NULL) || (q == (Quantum *) NULL))
{
status=MagickFalse;
continue;
}
center=(ssize_t) GetPixelChannels(image)*(image->columns+width)*(height/2L)+
GetPixelChannels(image)*(width/2);
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
PixelTrait threshold_traits=GetPixelChannelTraits(threshold_image,
channel);
if ((traits == UndefinedPixelTrait) ||
(threshold_traits == UndefinedPixelTrait))
continue;
if (((threshold_traits & CopyPixelTrait) != 0) ||
(GetPixelReadMask(image,p) == 0))
{
SetPixelChannel(threshold_image,channel,p[center+i],q);
continue;
}
pixels=p;
channel_bias[channel]=0.0;
channel_sum[channel]=0.0;
for (v=0; v < (ssize_t) height; v++)
{
for (u=0; u < (ssize_t) width; u++)
{
if (u == (ssize_t) (width-1))
channel_bias[channel]+=pixels[i];
channel_sum[channel]+=pixels[i];
pixels+=GetPixelChannels(image);
}
pixels+=GetPixelChannels(image)*image->columns;
}
}
for (x=0; x < (ssize_t) image->columns; x++)
{
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
double
mean;
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
PixelTrait threshold_traits=GetPixelChannelTraits(threshold_image,
channel);
if ((traits == UndefinedPixelTrait) ||
(threshold_traits == UndefinedPixelTrait))
continue;
if (((threshold_traits & CopyPixelTrait) != 0) ||
(GetPixelReadMask(image,p) == 0))
{
SetPixelChannel(threshold_image,channel,p[center+i],q);
continue;
}
channel_sum[channel]-=channel_bias[channel];
channel_bias[channel]=0.0;
pixels=p;
for (v=0; v < (ssize_t) height; v++)
{
channel_bias[channel]+=pixels[i];
pixels+=(width-1)*GetPixelChannels(image);
channel_sum[channel]+=pixels[i];
pixels+=GetPixelChannels(image)*(image->columns+1);
}
mean=(double) (channel_sum[channel]/number_pixels+bias);
SetPixelChannel(threshold_image,channel,(Quantum) ((double)
p[center+i] <= mean ? 0 : QuantumRange),q);
}
p+=GetPixelChannels(image);
q+=GetPixelChannels(threshold_image);
}
if (SyncCacheViewAuthenticPixels(threshold_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_AdaptiveThresholdImage)
#endif
proceed=SetImageProgress(image,AdaptiveThresholdImageTag,progress++,
image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
threshold_image->type=image->type;
threshold_view=DestroyCacheView(threshold_view);
image_view=DestroyCacheView(image_view);
if (status == MagickFalse)
threshold_image=DestroyImage(threshold_image);
return(threshold_image);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% B i l e v e l I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% BilevelImage() changes the value of individual pixels based on the
% intensity of each pixel channel. The result is a high-contrast image.
%
% More precisely each channel value of the image is 'thresholded' so that if
% it is equal to or less than the given value it is set to zero, while any
% value greater than that give is set to it maximum or QuantumRange.
%
% This function is what is used to implement the "-threshold" operator for
% the command line API.
%
% If the default channel setting is given the image is thresholded using just
% the gray 'intensity' of the image, rather than the individual channels.
%
% The format of the BilevelImage method is:
%
% MagickBooleanType BilevelImage(Image *image,const double threshold,
% ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o threshold: define the threshold values.
%
% o exception: return any errors or warnings in this structure.
%
% Aside: You can get the same results as operator using LevelImages()
% with the 'threshold' value for both the black_point and the white_point.
%
*/
MagickExport MagickBooleanType BilevelImage(Image *image,const double threshold,
ExceptionInfo *exception)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view;
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,exception) == MagickFalse)
return(MagickFalse);
if (IsGrayColorspace(image->colorspace) != MagickFalse)
(void) SetImageColorspace(image,sRGBColorspace,exception);
/*
Bilevel threshold image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(progress,status) \
magick_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register ssize_t
x;
register Quantum
*magick_restrict q;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (Quantum *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
double
pixel;
register ssize_t
i;
if (GetPixelReadMask(image,q) == 0)
{
q+=GetPixelChannels(image);
continue;
}
pixel=GetPixelIntensity(image,q);
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
if ((traits & UpdatePixelTrait) == 0)
continue;
if (image->channel_mask != DefaultChannels)
pixel=(double) q[i];
q[i]=(Quantum) (pixel <= threshold ? 0 : QuantumRange);
}
q+=GetPixelChannels(image);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_BilevelImage)
#endif
proceed=SetImageProgress(image,ThresholdImageTag,progress++,
image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% B l a c k T h r e s h o l d I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% BlackThresholdImage() is like ThresholdImage() but forces all pixels below
% the threshold into black while leaving all pixels at or above the threshold
% unchanged.
%
% The format of the BlackThresholdImage method is:
%
% MagickBooleanType BlackThresholdImage(Image *image,
% const char *threshold,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o threshold: define the threshold value.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType BlackThresholdImage(Image *image,
const char *thresholds,ExceptionInfo *exception)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view;
GeometryInfo
geometry_info;
MagickBooleanType
status;
MagickOffsetType
progress;
PixelInfo
threshold;
MagickStatusType
flags;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (thresholds == (const char *) NULL)
return(MagickTrue);
if (SetImageStorageClass(image,DirectClass,exception) == MagickFalse)
return(MagickFalse);
if (IsGrayColorspace(image->colorspace) != MagickFalse)
(void) SetImageColorspace(image,sRGBColorspace,exception);
GetPixelInfo(image,&threshold);
flags=ParseGeometry(thresholds,&geometry_info);
threshold.red=geometry_info.rho;
threshold.green=geometry_info.rho;
threshold.blue=geometry_info.rho;
threshold.black=geometry_info.rho;
threshold.alpha=100.0;
if ((flags & SigmaValue) != 0)
threshold.green=geometry_info.sigma;
if ((flags & XiValue) != 0)
threshold.blue=geometry_info.xi;
if ((flags & PsiValue) != 0)
threshold.alpha=geometry_info.psi;
if (threshold.colorspace == CMYKColorspace)
{
if ((flags & PsiValue) != 0)
threshold.black=geometry_info.psi;
if ((flags & ChiValue) != 0)
threshold.alpha=geometry_info.chi;
}
if ((flags & PercentValue) != 0)
{
threshold.red*=(MagickRealType) (QuantumRange/100.0);
threshold.green*=(MagickRealType) (QuantumRange/100.0);
threshold.blue*=(MagickRealType) (QuantumRange/100.0);
threshold.black*=(MagickRealType) (QuantumRange/100.0);
threshold.alpha*=(MagickRealType) (QuantumRange/100.0);
}
/*
White threshold image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(progress,status) \
magick_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register ssize_t
x;
register Quantum
*magick_restrict q;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (Quantum *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
double
pixel;
register ssize_t
i;
if (GetPixelReadMask(image,q) == 0)
{
q+=GetPixelChannels(image);
continue;
}
pixel=GetPixelIntensity(image,q);
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
if ((traits & UpdatePixelTrait) == 0)
continue;
if (image->channel_mask != DefaultChannels)
pixel=(double) q[i];
if (pixel < GetPixelInfoChannel(&threshold,channel))
q[i]=(Quantum) 0;
}
q+=GetPixelChannels(image);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_BlackThresholdImage)
#endif
proceed=SetImageProgress(image,ThresholdImageTag,progress++,
image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% C l a m p I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ClampImage() set each pixel whose value is below zero to zero and any the
% pixel whose value is above the quantum range to the quantum range (e.g.
% 65535) otherwise the pixel value remains unchanged.
%
% The format of the ClampImage method is:
%
% MagickBooleanType ClampImage(Image *image,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType ClampImage(Image *image,ExceptionInfo *exception)
{
#define ClampImageTag "Clamp/Image"
CacheView
*image_view;
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 (image->storage_class == PseudoClass)
{
register ssize_t
i;
register PixelInfo
*magick_restrict q;
q=image->colormap;
for (i=0; i < (ssize_t) image->colors; i++)
{
q->red=(double) ClampPixel(q->red);
q->green=(double) ClampPixel(q->green);
q->blue=(double) ClampPixel(q->blue);
q->alpha=(double) ClampPixel(q->alpha);
q++;
}
return(SyncImage(image,exception));
}
/*
Clamp image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(progress,status) \
magick_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register ssize_t
x;
register Quantum
*magick_restrict q;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (Quantum *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
register ssize_t
i;
if (GetPixelReadMask(image,q) == 0)
{
q+=GetPixelChannels(image);
continue;
}
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
if ((traits & UpdatePixelTrait) == 0)
continue;
q[i]=ClampPixel(q[i]);
}
q+=GetPixelChannels(image);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_ClampImage)
#endif
proceed=SetImageProgress(image,ClampImageTag,progress++,image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% D e s t r o y T h r e s h o l d M a p %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DestroyThresholdMap() de-allocate the given ThresholdMap
%
% The format of the ListThresholdMaps method is:
%
% ThresholdMap *DestroyThresholdMap(Threshold *map)
%
% A description of each parameter follows.
%
% o map: Pointer to the Threshold map to destroy
%
*/
MagickExport ThresholdMap *DestroyThresholdMap(ThresholdMap *map)
{
assert(map != (ThresholdMap *) NULL);
if (map->map_id != (char *) NULL)
map->map_id=DestroyString(map->map_id);
if (map->description != (char *) NULL)
map->description=DestroyString(map->description);
if (map->levels != (ssize_t *) NULL)
map->levels=(ssize_t *) RelinquishMagickMemory(map->levels);
map=(ThresholdMap *) RelinquishMagickMemory(map);
return(map);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t T h r e s h o l d M a p %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetThresholdMap() loads and searches one or more threshold map files for the
% map matching the given name or alias.
%
% The format of the GetThresholdMap method is:
%
% ThresholdMap *GetThresholdMap(const char *map_id,
% ExceptionInfo *exception)
%
% A description of each parameter follows.
%
% o map_id: ID of the map to look for.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport ThresholdMap *GetThresholdMap(const char *map_id,
ExceptionInfo *exception)
{
ThresholdMap
*map;
map=GetThresholdMapFile(MinimalThresholdMap,"built-in",map_id,exception);
if (map != (ThresholdMap *) NULL)
return(map);
#if !defined(MAGICKCORE_ZERO_CONFIGURATION_SUPPORT)
{
const StringInfo
*option;
LinkedListInfo
*options;
options=GetConfigureOptions(ThresholdsFilename,exception);
option=(const StringInfo *) GetNextValueInLinkedList(options);
while (option != (const StringInfo *) NULL)
{
map=GetThresholdMapFile((const char *) GetStringInfoDatum(option),
GetStringInfoPath(option),map_id,exception);
if (map != (ThresholdMap *) NULL)
break;
option=(const StringInfo *) GetNextValueInLinkedList(options);
}
options=DestroyConfigureOptions(options);
}
#endif
return(map);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ G e t T h r e s h o l d M a p F i l e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetThresholdMapFile() look for a given threshold map name or alias in the
% given XML file data, and return the allocated the map when found.
%
% The format of the ListThresholdMaps method is:
%
% ThresholdMap *GetThresholdMap(const char *xml,const char *filename,
% const char *map_id,ExceptionInfo *exception)
%
% A description of each parameter follows.
%
% o xml: The threshold map list in XML format.
%
% o filename: The threshold map XML filename.
%
% o map_id: ID of the map to look for in XML list.
%
% o exception: return any errors or warnings in this structure.
%
*/
static ThresholdMap *GetThresholdMapFile(const char *xml,const char *filename,
const char *map_id,ExceptionInfo *exception)
{
char
*p;
const char
*attribute,
*content;
double
value;
register ssize_t
i;
ThresholdMap
*map;
XMLTreeInfo
*description,
*levels,
*threshold,
*thresholds;
(void) LogMagickEvent(ConfigureEvent,GetMagickModule(),
"Loading threshold map file \"%s\" ...",filename);
map=(ThresholdMap *) NULL;
thresholds=NewXMLTree(xml,exception);
if (thresholds == (XMLTreeInfo *) NULL)
return(map);
for (threshold=GetXMLTreeChild(thresholds,"threshold");
threshold != (XMLTreeInfo *) NULL;
threshold=GetNextXMLTreeTag(threshold))
{
attribute=GetXMLTreeAttribute(threshold,"map");
if ((attribute != (char *) NULL) && (LocaleCompare(map_id,attribute) == 0))
break;
attribute=GetXMLTreeAttribute(threshold,"alias");
if ((attribute != (char *) NULL) && (LocaleCompare(map_id,attribute) == 0))
break;
}
if (threshold == (XMLTreeInfo *) NULL)
{
thresholds=DestroyXMLTree(thresholds);
return(map);
}
description=GetXMLTreeChild(threshold,"description");
if (description == (XMLTreeInfo *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingElement", "<description>, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
return(map);
}
levels=GetXMLTreeChild(threshold,"levels");
if (levels == (XMLTreeInfo *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingElement", "<levels>, map \"%s\"", map_id);
thresholds=DestroyXMLTree(thresholds);
return(map);
}
map=(ThresholdMap *) AcquireMagickMemory(sizeof(ThresholdMap));
if (map == (ThresholdMap *) NULL)
ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireThresholdMap");
map->map_id=(char *) NULL;
map->description=(char *) NULL;
map->levels=(ssize_t *) NULL;
attribute=GetXMLTreeAttribute(threshold,"map");
if (attribute != (char *) NULL)
map->map_id=ConstantString(attribute);
content=GetXMLTreeContent(description);
if (content != (char *) NULL)
map->description=ConstantString(content);
attribute=GetXMLTreeAttribute(levels,"width");
if (attribute == (char *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingAttribute", "<levels width>, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
map->width=StringToUnsignedLong(attribute);
if (map->width == 0)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidAttribute", "<levels width>, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
attribute=GetXMLTreeAttribute(levels,"height");
if (attribute == (char *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingAttribute", "<levels height>, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
map->height=StringToUnsignedLong(attribute);
if (map->height == 0)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidAttribute", "<levels height>, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
attribute=GetXMLTreeAttribute(levels,"divisor");
if (attribute == (char *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingAttribute", "<levels divisor>, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
map->divisor=(ssize_t) StringToLong(attribute);
if (map->divisor < 2)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidAttribute", "<levels divisor>, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
content=GetXMLTreeContent(levels);
if (content == (char *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingContent", "<levels>, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
map->levels=(ssize_t *) AcquireQuantumMemory((size_t) map->width,map->height*
sizeof(*map->levels));
if (map->levels == (ssize_t *) NULL)
ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireThresholdMap");
for (i=0; i < (ssize_t) (map->width*map->height); i++)
{
map->levels[i]=(ssize_t) strtol(content,&p,10);
if (p == content)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidContent", "<level> too few values, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
if ((map->levels[i] < 0) || (map->levels[i] > map->divisor))
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidContent", "<level> %.20g out of range, map \"%s\"",
(double) map->levels[i],map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
content=p;
}
value=(double) strtol(content,&p,10);
(void) value;
if (p != content)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidContent", "<level> too many values, map \"%s\"",map_id);
thresholds=DestroyXMLTree(thresholds);
map=DestroyThresholdMap(map);
return(map);
}
thresholds=DestroyXMLTree(thresholds);
return(map);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ L i s t T h r e s h o l d M a p F i l e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ListThresholdMapFile() lists the threshold maps and their descriptions
% in the given XML file data.
%
% The format of the ListThresholdMaps method is:
%
% MagickBooleanType ListThresholdMaps(FILE *file,const char*xml,
% const char *filename,ExceptionInfo *exception)
%
% A description of each parameter follows.
%
% o file: An pointer to the output FILE.
%
% o xml: The threshold map list in XML format.
%
% o filename: The threshold map XML filename.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickBooleanType ListThresholdMapFile(FILE *file,const char *xml,
const char *filename,ExceptionInfo *exception)
{
const char
*alias,
*content,
*map;
XMLTreeInfo
*description,
*threshold,
*thresholds;
assert( xml != (char *) NULL );
assert( file != (FILE *) NULL );
(void) LogMagickEvent(ConfigureEvent,GetMagickModule(),
"Loading threshold map file \"%s\" ...",filename);
thresholds=NewXMLTree(xml,exception);
if ( thresholds == (XMLTreeInfo *) NULL )
return(MagickFalse);
(void) FormatLocaleFile(file,"%-16s %-12s %s\n","Map","Alias","Description");
(void) FormatLocaleFile(file,
"----------------------------------------------------\n");
threshold=GetXMLTreeChild(thresholds,"threshold");
for ( ; threshold != (XMLTreeInfo *) NULL;
threshold=GetNextXMLTreeTag(threshold))
{
map=GetXMLTreeAttribute(threshold,"map");
if (map == (char *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingAttribute", "<map>");
thresholds=DestroyXMLTree(thresholds);
return(MagickFalse);
}
alias=GetXMLTreeAttribute(threshold,"alias");
description=GetXMLTreeChild(threshold,"description");
if (description == (XMLTreeInfo *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingElement", "<description>, map \"%s\"",map);
thresholds=DestroyXMLTree(thresholds);
return(MagickFalse);
}
content=GetXMLTreeContent(description);
if (content == (char *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlMissingContent", "<description>, map \"%s\"", map);
thresholds=DestroyXMLTree(thresholds);
return(MagickFalse);
}
(void) FormatLocaleFile(file,"%-16s %-12s %s\n",map,alias ? alias : "",
content);
}
thresholds=DestroyXMLTree(thresholds);
return(MagickTrue);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% L i s t T h r e s h o l d M a p s %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ListThresholdMaps() lists the threshold maps and their descriptions
% as defined by "threshold.xml" to a file.
%
% The format of the ListThresholdMaps method is:
%
% MagickBooleanType ListThresholdMaps(FILE *file,ExceptionInfo *exception)
%
% A description of each parameter follows.
%
% o file: An pointer to the output FILE.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType ListThresholdMaps(FILE *file,
ExceptionInfo *exception)
{
const StringInfo
*option;
LinkedListInfo
*options;
MagickStatusType
status;
status=MagickTrue;
if (file == (FILE *) NULL)
file=stdout;
options=GetConfigureOptions(ThresholdsFilename,exception);
(void) FormatLocaleFile(file,
"\n Threshold Maps for Ordered Dither Operations\n");
option=(const StringInfo *) GetNextValueInLinkedList(options);
while (option != (const StringInfo *) NULL)
{
(void) FormatLocaleFile(file,"\nPath: %s\n\n",GetStringInfoPath(option));
status&=ListThresholdMapFile(file,(const char *) GetStringInfoDatum(option),
GetStringInfoPath(option),exception);
option=(const StringInfo *) GetNextValueInLinkedList(options);
}
options=DestroyConfigureOptions(options);
return(status != 0 ? MagickTrue : MagickFalse);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% O r d e r e d D i t h e r I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% OrderedDitherImage() will perform a ordered dither based on a number
% of pre-defined dithering threshold maps, but over multiple intensity
% levels, which can be different for different channels, according to the
% input argument.
%
% The format of the OrderedDitherImage method is:
%
% MagickBooleanType OrderedDitherImage(Image *image,
% const char *threshold_map,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o threshold_map: A string containing the name of the threshold dither
% map to use, followed by zero or more numbers representing the number
% of color levels tho dither between.
%
% Any level number less than 2 will be equivalent to 2, and means only
% binary dithering will be applied to each color channel.
%
% No numbers also means a 2 level (bitmap) dither will be applied to all
% channels, while a single number is the number of levels applied to each
% channel in sequence. More numbers will be applied in turn to each of
% the color channels.
%
% For example: "o3x3,6" will generate a 6 level posterization of the
% image with a ordered 3x3 diffused pixel dither being applied between
% each level. While checker,8,8,4 will produce a 332 colormaped image
% with only a single checkerboard hash pattern (50% grey) between each
% color level, to basically double the number of color levels with
% a bare minimim of dithering.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType OrderedDitherImage(Image *image,
const char *threshold_map,ExceptionInfo *exception)
{
#define DitherImageTag "Dither/Image"
CacheView
*image_view;
char
token[MagickPathExtent];
const char
*p;
double
levels[CompositePixelChannel];
MagickBooleanType
status;
MagickOffsetType
progress;
register ssize_t
i;
ssize_t
y;
ThresholdMap
*map;
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);
if (threshold_map == (const char *) NULL)
return(MagickTrue);
p=(char *) threshold_map;
while (((isspace((int) ((unsigned char) *p)) != 0) || (*p == ',')) &&
(*p != '\0'))
p++;
threshold_map=p;
while (((isspace((int) ((unsigned char) *p)) == 0) && (*p != ',')) &&
(*p != '\0'))
{
if ((p-threshold_map) >= (MagickPathExtent-1))
break;
token[p-threshold_map]=(*p);
p++;
}
token[p-threshold_map]='\0';
map=GetThresholdMap(token,exception);
if (map == (ThresholdMap *) NULL)
{
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"InvalidArgument","%s : '%s'","ordered-dither",threshold_map);
return(MagickFalse);
}
for (i=0; i < MaxPixelChannels; i++)
levels[i]=2.0;
p=strchr((char *) threshold_map,',');
if ((p != (char *) NULL) && (isdigit((int) ((unsigned char) *(++p))) != 0))
for (i=0; (*p != '\0') && (i < MaxPixelChannels); i++)
{
GetNextToken(p,&p,MagickPathExtent,token);
if (*token == ',')
GetNextToken(p,&p,MagickPathExtent,token);
levels[i]=StringToDouble(token,(char **) NULL);
}
for (i=0; i < MaxPixelChannels; i++)
if (fabs(levels[i]) >= 1)
levels[i]-=1.0;
if (SetImageStorageClass(image,DirectClass,exception) == MagickFalse)
return(MagickFalse);
status=MagickTrue;
progress=0;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(progress,status) \
magick_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register ssize_t
x;
register Quantum
*magick_restrict q;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (Quantum *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
register ssize_t
i;
ssize_t
n;
n=0;
if (GetPixelReadMask(image,q) == 0)
{
q+=GetPixelChannels(image);
continue;
}
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
ssize_t
level,
threshold;
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
if ((traits & UpdatePixelTrait) == 0)
continue;
if (fabs(levels[n++]) < MagickEpsilon)
continue;
threshold=(ssize_t) (QuantumScale*q[i]*(levels[n]*(map->divisor-1)+1));
level=threshold/(map->divisor-1);
threshold-=level*(map->divisor-1);
q[i]=ClampToQuantum((double) (level+(threshold >=
map->levels[(x % map->width)+map->width*(y % map->height)]))*
QuantumRange/levels[n]);
n++;
}
q+=GetPixelChannels(image);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_OrderedDitherImage)
#endif
proceed=SetImageProgress(image,DitherImageTag,progress++,image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
map=DestroyThresholdMap(map);
return(MagickTrue);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% P e r c e p t i b l e I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% PerceptibleImage() set each pixel whose value is less than |epsilon| to
% epsilon or -epsilon (whichever is closer) otherwise the pixel value remains
% unchanged.
%
% The format of the PerceptibleImage method is:
%
% MagickBooleanType PerceptibleImage(Image *image,const double epsilon,
% ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o epsilon: the epsilon threshold (e.g. 1.0e-9).
%
% o exception: return any errors or warnings in this structure.
%
*/
static inline Quantum PerceptibleThreshold(const Quantum quantum,
const double epsilon)
{
double
sign;
sign=(double) quantum < 0.0 ? -1.0 : 1.0;
if ((sign*quantum) >= epsilon)
return(quantum);
return((Quantum) (sign*epsilon));
}
MagickExport MagickBooleanType PerceptibleImage(Image *image,
const double epsilon,ExceptionInfo *exception)
{
#define PerceptibleImageTag "Perceptible/Image"
CacheView
*image_view;
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 (image->storage_class == PseudoClass)
{
register ssize_t
i;
register PixelInfo
*magick_restrict q;
q=image->colormap;
for (i=0; i < (ssize_t) image->colors; i++)
{
q->red=(double) PerceptibleThreshold(ClampToQuantum(q->red),
epsilon);
q->green=(double) PerceptibleThreshold(ClampToQuantum(q->green),
epsilon);
q->blue=(double) PerceptibleThreshold(ClampToQuantum(q->blue),
epsilon);
q->alpha=(double) PerceptibleThreshold(ClampToQuantum(q->alpha),
epsilon);
q++;
}
return(SyncImage(image,exception));
}
/*
Perceptible image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(progress,status) \
magick_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register ssize_t
x;
register Quantum
*magick_restrict q;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (Quantum *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
register ssize_t
i;
if (GetPixelReadMask(image,q) == 0)
{
q+=GetPixelChannels(image);
continue;
}
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
if (traits == UndefinedPixelTrait)
continue;
q[i]=PerceptibleThreshold(q[i],epsilon);
}
q+=GetPixelChannels(image);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_PerceptibleImage)
#endif
proceed=SetImageProgress(image,PerceptibleImageTag,progress++,image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% R a n d o m T h r e s h o l d I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% RandomThresholdImage() changes the value of individual pixels based on the
% intensity of each pixel compared to a random threshold. The result is a
% low-contrast, two color image.
%
% The format of the RandomThresholdImage method is:
%
% MagickBooleanType RandomThresholdImage(Image *image,
% const char *thresholds,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o low,high: Specify the high and low thresholds. These values range from
% 0 to QuantumRange.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType RandomThresholdImage(Image *image,
const double min_threshold, const double max_threshold,ExceptionInfo *exception)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view;
MagickBooleanType
status;
MagickOffsetType
progress;
PixelInfo
threshold;
RandomInfo
**magick_restrict random_info;
ssize_t
y;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
unsigned long
key;
#endif
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);
if (SetImageStorageClass(image,DirectClass,exception) == MagickFalse)
return(MagickFalse);
GetPixelInfo(image,&threshold);
/*
Random threshold image.
*/
status=MagickTrue;
progress=0;
random_info=AcquireRandomInfoThreadSet();
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
key=GetRandomSecretKey(random_info[0]);
#pragma omp parallel for schedule(static,4) shared(progress,status) \
magick_threads(image,image,image->rows,key == ~0UL)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
const int
id = GetOpenMPThreadId();
register Quantum
*magick_restrict q;
register ssize_t
x;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (Quantum *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
register ssize_t
i;
if (GetPixelReadMask(image,q) == 0)
{
q+=GetPixelChannels(image);
continue;
}
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
double
threshold;
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
if ((traits & UpdatePixelTrait) == 0)
continue;
if ((double) q[i] < min_threshold)
threshold=min_threshold;
else
if ((double) q[i] > max_threshold)
threshold=max_threshold;
else
threshold=(double) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
q[i]=(double) q[i] <= threshold ? 0 : QuantumRange;
}
q+=GetPixelChannels(image);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_RandomThresholdImage)
#endif
proceed=SetImageProgress(image,ThresholdImageTag,progress++,
image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
random_info=DestroyRandomInfoThreadSet(random_info);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% W h i t e T h r e s h o l d I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% WhiteThresholdImage() is like ThresholdImage() but forces all pixels above
% the threshold into white while leaving all pixels at or below the threshold
% unchanged.
%
% The format of the WhiteThresholdImage method is:
%
% MagickBooleanType WhiteThresholdImage(Image *image,
% const char *threshold,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o threshold: Define the threshold value.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType WhiteThresholdImage(Image *image,
const char *thresholds,ExceptionInfo *exception)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view;
GeometryInfo
geometry_info;
MagickBooleanType
status;
MagickOffsetType
progress;
PixelInfo
threshold;
MagickStatusType
flags;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (thresholds == (const char *) NULL)
return(MagickTrue);
if (SetImageStorageClass(image,DirectClass,exception) == MagickFalse)
return(MagickFalse);
if (IsGrayColorspace(image->colorspace) != MagickFalse)
(void) TransformImageColorspace(image,sRGBColorspace,exception);
GetPixelInfo(image,&threshold);
flags=ParseGeometry(thresholds,&geometry_info);
threshold.red=geometry_info.rho;
threshold.green=geometry_info.rho;
threshold.blue=geometry_info.rho;
threshold.black=geometry_info.rho;
threshold.alpha=100.0;
if ((flags & SigmaValue) != 0)
threshold.green=geometry_info.sigma;
if ((flags & XiValue) != 0)
threshold.blue=geometry_info.xi;
if ((flags & PsiValue) != 0)
threshold.alpha=geometry_info.psi;
if (threshold.colorspace == CMYKColorspace)
{
if ((flags & PsiValue) != 0)
threshold.black=geometry_info.psi;
if ((flags & ChiValue) != 0)
threshold.alpha=geometry_info.chi;
}
if ((flags & PercentValue) != 0)
{
threshold.red*=(MagickRealType) (QuantumRange/100.0);
threshold.green*=(MagickRealType) (QuantumRange/100.0);
threshold.blue*=(MagickRealType) (QuantumRange/100.0);
threshold.black*=(MagickRealType) (QuantumRange/100.0);
threshold.alpha*=(MagickRealType) (QuantumRange/100.0);
}
/*
White threshold image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static,4) shared(progress,status) \
magick_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register ssize_t
x;
register Quantum
*magick_restrict q;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (Quantum *) NULL)
{
status=MagickFalse;
continue;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
double
pixel;
register ssize_t
i;
if (GetPixelReadMask(image,q) == 0)
{
q+=GetPixelChannels(image);
continue;
}
pixel=GetPixelIntensity(image,q);
for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
{
PixelChannel channel=GetPixelChannelChannel(image,i);
PixelTrait traits=GetPixelChannelTraits(image,channel);
if ((traits & UpdatePixelTrait) == 0)
continue;
if (image->channel_mask != DefaultChannels)
pixel=(double) q[i];
if (pixel > GetPixelInfoChannel(&threshold,channel))
q[i]=QuantumRange;
}
q+=GetPixelChannels(image);
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_WhiteThresholdImage)
#endif
proceed=SetImageProgress(image,ThresholdImageTag,progress++,
image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
return(status);
}