/* [<][>][^][v][top][bottom][index][help] */
DEFINITIONS
This source file includes following definitions.
- AdaptiveThresholdImage
- BilevelImage
- BilevelImageChannel
- BlackThresholdImage
- BlackThresholdImageChannel
- ClampToUnsignedQuantum
- ClampImage
- ClampImageChannel
- DestroyThresholdMap
- GetThresholdMapFile
- GetThresholdMap
- ListThresholdMapFile
- ListThresholdMaps
- OrderedDitherImage
- OrderedDitherImageChannel
- OrderedPosterizeImage
- OrderedPosterizeImageChannel
- RandomThresholdImage
- RandomThresholdImageChannel
- WhiteThresholdImage
- WhiteThresholdImageChannel
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% 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 %
% John Cristy %
% October 1996 %
% %
% %
% Copyright 1999-2011 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 "magick/studio.h"
#include "magick/property.h"
#include "magick/blob.h"
#include "magick/cache-view.h"
#include "magick/color.h"
#include "magick/color-private.h"
#include "magick/colormap.h"
#include "magick/colorspace.h"
#include "magick/configure.h"
#include "magick/constitute.h"
#include "magick/decorate.h"
#include "magick/draw.h"
#include "magick/enhance.h"
#include "magick/exception.h"
#include "magick/exception-private.h"
#include "magick/effect.h"
#include "magick/fx.h"
#include "magick/gem.h"
#include "magick/geometry.h"
#include "magick/image-private.h"
#include "magick/list.h"
#include "magick/log.h"
#include "magick/memory_.h"
#include "magick/monitor.h"
#include "magick/monitor-private.h"
#include "magick/montage.h"
#include "magick/option.h"
#include "magick/pixel-private.h"
#include "magick/quantize.h"
#include "magick/quantum.h"
#include "magick/random_.h"
#include "magick/random-private.h"
#include "magick/resize.h"
#include "magick/resource_.h"
#include "magick/segment.h"
#include "magick/shear.h"
#include "magick/signature-private.h"
#include "magick/string_.h"
#include "magick/string-private.h"
#include "magick/thread-private.h"
#include "magick/threshold.h"
#include "magick/transform.h"
#include "magick/xml-tree.h"
/*
Define declarations.
*/
#define ThresholdsFilename "thresholds.xml"
/*
Typedef declarations.
*/
struct _ThresholdMap
{
char
*map_id,
*description;
size_t
width,
height;
ssize_t
divisor,
*levels;
};
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% 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 ssize_t offset,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 offset: the mean offset.
%
% 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 ssize_t offset,
ExceptionInfo *exception)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view,
*threshold_view;
Image
*threshold_image;
MagickBooleanType
status;
MagickOffsetType
progress;
MagickPixelPacket
zero;
MagickRealType
number_pixels;
ssize_t
y;
assert(image != (const Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickSignature);
threshold_image=CloneImage(image,0,0,MagickTrue,exception);
if (threshold_image == (Image *) NULL)
return((Image *) NULL);
if (SetImageStorageClass(threshold_image,DirectClass) == MagickFalse)
{
InheritException(exception,&threshold_image->exception);
threshold_image=DestroyImage(threshold_image);
return((Image *) NULL);
}
/*
Local adaptive threshold.
*/
status=MagickTrue;
progress=0;
GetMagickPixelPacket(image,&zero);
number_pixels=(MagickRealType) width*height;
image_view=AcquireCacheView(image);
threshold_view=AcquireCacheView(threshold_image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(dynamic,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
MagickBooleanType
sync;
register const IndexPacket
*restrict indexes;
register const PixelPacket
*restrict p;
register IndexPacket
*restrict threshold_indexes;
register ssize_t
x;
register PixelPacket
*restrict q;
if (status == MagickFalse)
continue;
p=GetCacheViewVirtualPixels(image_view,-((ssize_t) width/2L),y-(ssize_t)
height/2L,image->columns+width,height,exception);
q=GetCacheViewAuthenticPixels(threshold_view,0,y,threshold_image->columns,1,
exception);
if ((p == (const PixelPacket *) NULL) || (q == (PixelPacket *) NULL))
{
status=MagickFalse;
continue;
}
indexes=GetCacheViewVirtualIndexQueue(image_view);
threshold_indexes=GetCacheViewAuthenticIndexQueue(threshold_view);
for (x=0; x < (ssize_t) image->columns; x++)
{
MagickPixelPacket
mean,
pixel;
register const PixelPacket
*r;
register ssize_t
u;
ssize_t
v;
pixel=zero;
mean=zero;
r=p;
for (v=0; v < (ssize_t) height; v++)
{
for (u=0; u < (ssize_t) width; u++)
{
pixel.red+=r[u].red;
pixel.green+=r[u].green;
pixel.blue+=r[u].blue;
pixel.opacity+=r[u].opacity;
if (image->colorspace == CMYKColorspace)
pixel.index=(MagickRealType) indexes[x+(r-p)+u];
}
r+=image->columns+width;
}
mean.red=(MagickRealType) (pixel.red/number_pixels+offset);
mean.green=(MagickRealType) (pixel.green/number_pixels+offset);
mean.blue=(MagickRealType) (pixel.blue/number_pixels+offset);
mean.opacity=(MagickRealType) (pixel.opacity/number_pixels+offset);
if (image->colorspace == CMYKColorspace)
mean.index=(MagickRealType) (pixel.index/number_pixels+offset);
q->red=(Quantum) (((MagickRealType) q->red <= mean.red) ?
0 : QuantumRange);
q->green=(Quantum) (((MagickRealType) q->green <= mean.green) ?
0 : QuantumRange);
q->blue=(Quantum) (((MagickRealType) q->blue <= mean.blue) ?
0 : QuantumRange);
q->opacity=(Quantum) (((MagickRealType) q->opacity <= mean.opacity) ?
0 : QuantumRange);
if (image->colorspace == CMYKColorspace)
threshold_indexes[x]=(IndexPacket) (((MagickRealType)
threshold_indexes[x] <= mean.index) ? 0 : QuantumRange);
p++;
q++;
}
sync=SyncCacheViewAuthenticPixels(threshold_view,exception);
if (sync == 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,ThresholdImageTag,progress++,
image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
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 BilevelImageChannel method is:
%
% MagickBooleanType BilevelImage(Image *image,const double threshold)
% MagickBooleanType BilevelImageChannel(Image *image,
% const ChannelType channel,const double threshold)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: the channel type.
%
% o threshold: define the threshold values.
%
% Aside: You can get the same results as operator using LevelImageChannels()
% with the 'threshold' value for both the black_point and the white_point.
%
*/
MagickExport MagickBooleanType BilevelImage(Image *image,const double threshold)
{
MagickBooleanType
status;
status=BilevelImageChannel(image,DefaultChannels,threshold);
return(status);
}
MagickExport MagickBooleanType BilevelImageChannel(Image *image,
const ChannelType channel,const double threshold)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view;
ExceptionInfo
*exception;
MagickBooleanType
status;
MagickOffsetType
progress;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (SetImageStorageClass(image,DirectClass) == MagickFalse)
return(MagickFalse);
/*
Bilevel threshold image.
*/
status=MagickTrue;
progress=0;
exception=(&image->exception);
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(dynamic,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register IndexPacket
*restrict indexes;
register ssize_t
x;
register PixelPacket
*restrict q;
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);
if (channel == DefaultChannels)
{
for (x=0; x < (ssize_t) image->columns; x++)
{
q->red=(Quantum) ((MagickRealType) PixelIntensityToQuantum(q) <=
threshold ? 0 : QuantumRange);
q->green=q->red;
q->blue=q->red;
q++;
}
}
else
for (x=0; x < (ssize_t) image->columns; x++)
{
if ((channel & RedChannel) != 0)
q->red=(Quantum) ((MagickRealType) q->red <= threshold ? 0 :
QuantumRange);
if ((channel & GreenChannel) != 0)
q->green=(Quantum) ((MagickRealType) q->green <= threshold ? 0 :
QuantumRange);
if ((channel & BlueChannel) != 0)
q->blue=(Quantum) ((MagickRealType) q->blue <= threshold ? 0 :
QuantumRange);
if ((channel & OpacityChannel) != 0)
{
if (image->matte == MagickFalse)
q->opacity=(Quantum) ((MagickRealType) q->opacity <= threshold ?
0 : QuantumRange);
else
q->opacity=(Quantum) ((MagickRealType) q->opacity <= threshold ?
OpaqueOpacity : TransparentOpacity);
}
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
indexes[x]=(IndexPacket) ((MagickRealType) indexes[x] <= threshold ?
0 : QuantumRange);
q++;
}
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_BilevelImageChannel)
#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)
% MagickBooleanType BlackThresholdImageChannel(Image *image,
% const ChannelType channel,const char *threshold,
% ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: the channel or channels to be thresholded.
%
% o threshold: Define the threshold value.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType BlackThresholdImage(Image *image,
const char *threshold)
{
MagickBooleanType
status;
status=BlackThresholdImageChannel(image,DefaultChannels,threshold,
&image->exception);
return(status);
}
MagickExport MagickBooleanType BlackThresholdImageChannel(Image *image,
const ChannelType channel,const char *thresholds,ExceptionInfo *exception)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view;
GeometryInfo
geometry_info;
MagickBooleanType
status;
MagickOffsetType
progress;
MagickPixelPacket
threshold;
MagickStatusType
flags;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (thresholds == (const char *) NULL)
return(MagickTrue);
if (SetImageStorageClass(image,DirectClass) == MagickFalse)
return(MagickFalse);
GetMagickPixelPacket(image,&threshold);
flags=ParseGeometry(thresholds,&geometry_info);
threshold.red=geometry_info.rho;
threshold.green=geometry_info.sigma;
if ((flags & SigmaValue) == 0)
threshold.green=threshold.red;
threshold.blue=geometry_info.xi;
if ((flags & XiValue) == 0)
threshold.blue=threshold.red;
threshold.opacity=geometry_info.psi;
if ((flags & PsiValue) == 0)
threshold.opacity=threshold.red;
threshold.index=geometry_info.chi;
if ((flags & ChiValue) == 0)
threshold.index=threshold.red;
if ((flags & PercentValue) != 0)
{
threshold.red*=(QuantumRange/100.0);
threshold.green*=(QuantumRange/100.0);
threshold.blue*=(QuantumRange/100.0);
threshold.opacity*=(QuantumRange/100.0);
threshold.index*=(QuantumRange/100.0);
}
/*
Black threshold image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(dynamic,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register IndexPacket
*restrict indexes;
register ssize_t
x;
register PixelPacket
*restrict q;
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);
for (x=0; x < (ssize_t) image->columns; x++)
{
if (channel != DefaultChannels)
{
if (PixelIntensity(q) < MagickPixelIntensity(&threshold))
{
q->red=(Quantum) 0;
q->green=(Quantum) 0;
q->blue=(Quantum) 0;
if (image->colorspace == CMYKColorspace)
indexes[x]=(Quantum) 0;
}
}
else
{
if (((channel & RedChannel) != 0) &&
((MagickRealType) q->red < threshold.red))
q->red=(Quantum) 0;
if (((channel & GreenChannel) != 0) &&
((MagickRealType) q->green < threshold.green))
q->green=(Quantum) 0;
if (((channel & BlueChannel) != 0) &&
((MagickRealType) q->blue < threshold.blue))
q->blue=(Quantum) 0;
if (((channel & OpacityChannel) != 0) &&
((MagickRealType) q->opacity < threshold.opacity))
q->opacity=(Quantum) 0;
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace) &&
((MagickRealType) indexes[x] < threshold.index))
indexes[x]=(Quantum) 0;
}
q++;
}
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_BlackThresholdImageChannel)
#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() restricts the color range from 0 to the quantum depth.
%
% The format of the ClampImageChannel method is:
%
% MagickBooleanType ClampImage(Image *image)
% MagickBooleanType ClampImageChannel(Image *image,
% const ChannelType channel)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: the channel type.
%
*/
static inline Quantum ClampToUnsignedQuantum(const Quantum quantum)
{
#if defined(MAGICKCORE_HDRI_SUPPORT)
if (quantum <= 0)
return(0);
if (quantum >= QuantumRange)
return(QuantumRange);
return(quantum);
#else
return(quantum);
#endif
}
MagickExport MagickBooleanType ClampImage(Image *image)
{
MagickBooleanType
status;
status=ClampImageChannel(image,DefaultChannels);
return(status);
}
MagickExport MagickBooleanType ClampImageChannel(Image *image,
const ChannelType channel)
{
#define ClampImageTag "Clamp/Image"
CacheView
*image_view;
ExceptionInfo
*exception;
MagickBooleanType
status;
MagickOffsetType
progress;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (image->storage_class == PseudoClass)
{
register ssize_t
i;
register PixelPacket
*restrict q;
q=image->colormap;
for (i=0; i < (ssize_t) image->colors; i++)
{
q->red=ClampToUnsignedQuantum(q->red);
q->green=ClampToUnsignedQuantum(q->green);
q->blue=ClampToUnsignedQuantum(q->blue);
q->opacity=ClampToUnsignedQuantum(q->opacity);
q++;
}
return(SyncImage(image));
}
/*
Clamp image.
*/
status=MagickTrue;
progress=0;
exception=(&image->exception);
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(dynamic,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register IndexPacket
*restrict indexes;
register ssize_t
x;
register PixelPacket
*restrict q;
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);
for (x=0; x < (ssize_t) image->columns; x++)
{
if ((channel & RedChannel) != 0)
q->red=ClampToUnsignedQuantum(q->red);
if ((channel & GreenChannel) != 0)
q->green=ClampToUnsignedQuantum(q->green);
if ((channel & BlueChannel) != 0)
q->blue=ClampToUnsignedQuantum(q->blue);
if ((channel & OpacityChannel) != 0)
q->opacity=ClampToUnsignedQuantum(q->opacity);
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
indexes[x]=(IndexPacket) ClampToUnsignedQuantum(indexes[x]);
q++;
}
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_ClampImageChannel)
#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 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.
%
*/
MagickExport ThresholdMap *GetThresholdMapFile(const char *xml,
const char *filename,const char *map_id,ExceptionInfo *exception)
{
const char
*attr,
*content;
double
value;
ThresholdMap
*map;
XMLTreeInfo
*description,
*levels,
*threshold,
*thresholds;
map = (ThresholdMap *)NULL;
(void) LogMagickEvent(ConfigureEvent,GetMagickModule(),
"Loading threshold map file \"%s\" ...",filename);
thresholds=NewXMLTree(xml,exception);
if ( thresholds == (XMLTreeInfo *)NULL )
return(map);
for( threshold = GetXMLTreeChild(thresholds,"threshold");
threshold != (XMLTreeInfo *)NULL;
threshold = GetNextXMLTreeTag(threshold) ) {
attr = GetXMLTreeAttribute(threshold, "map");
if ( (attr != (char *)NULL) && (LocaleCompare(map_id,attr) == 0) )
break;
attr = GetXMLTreeAttribute(threshold, "alias");
if ( (attr != (char *)NULL) && (LocaleCompare(map_id,attr) == 0) )
break;
}
if ( threshold == (XMLTreeInfo *)NULL ) {
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);
}
/* The map has been found -- Allocate a Threshold Map to return */
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;
/* Assign Basic Attributes */
attr = GetXMLTreeAttribute(threshold, "map");
if ( attr != (char *)NULL )
map->map_id = ConstantString(attr);
content = GetXMLTreeContent(description);
if ( content != (char *)NULL )
map->description = ConstantString(content);
attr = GetXMLTreeAttribute(levels, "width");
if ( attr == (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(attr);
if ( map->width == 0 ) {
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidAttribute", "<levels width>, map \"%s\"", map_id);
thresholds = DestroyXMLTree(thresholds);
map = DestroyThresholdMap(map);
return(map);
}
attr = GetXMLTreeAttribute(levels, "height");
if ( attr == (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(attr);
if ( map->height == 0 ) {
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidAttribute", "<levels height>, map \"%s\"", map_id);
thresholds = DestroyXMLTree(thresholds);
map = DestroyThresholdMap(map);
return(map);
}
attr = GetXMLTreeAttribute(levels, "divisor");
if ( attr == (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(attr);
if ( map->divisor < 2 ) {
(void) ThrowMagickException(exception,GetMagickModule(),OptionError,
"XmlInvalidAttribute", "<levels divisor>, map \"%s\"", map_id);
thresholds = DestroyXMLTree(thresholds);
map = DestroyThresholdMap(map);
return(map);
}
/* Allocate theshold levels array */
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");
{ /* parse levels into integer array */
ssize_t i;
char *p;
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);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t T h r e s h o l d M a p %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetThresholdMap() load and search one or more threshold map files for the
% a map matching the given name or aliase.
%
% 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)
{
const StringInfo
*option;
LinkedListInfo
*options;
ThresholdMap
*map;
map=(ThresholdMap *)NULL;
options=GetConfigureOptions(ThresholdsFilename,exception);
while (( option=(const StringInfo *) GetNextValueInLinkedList(options) )
!= (const StringInfo *) NULL && map == (ThresholdMap *)NULL )
map=GetThresholdMapFile((const char *) GetStringInfoDatum(option),
GetStringInfoPath(option),map_id,exception);
options=DestroyConfigureOptions(options);
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)
{
XMLTreeInfo *thresholds,*threshold,*description;
const char *map,*alias,*content;
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) fprintf(file,"%-16s %-12s %s\n", "Map", "Alias", "Description");
(void) fprintf(file,"----------------------------------------------------\n");
for( threshold = GetXMLTreeChild(thresholds,"threshold");
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");
/* alias is optional, no if test needed */
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) fprintf(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=MagickFalse;
if ( file == (FILE *)NULL )
file = stdout;
options=GetConfigureOptions(ThresholdsFilename,exception);
(void) fprintf(file, "\n Threshold Maps for Ordered Dither Operations\n");
while ( ( option=(const StringInfo *) GetNextValueInLinkedList(options) )
!= (const StringInfo *) NULL)
{
(void) fprintf(file,"\nPATH: %s\n\n",GetStringInfoPath(option));
status|=ListThresholdMapFile(file,(const char *) GetStringInfoDatum(option),
GetStringInfoPath(option),exception);
}
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() uses the ordered dithering technique of reducing color
% images to monochrome using positional information to retain as much
% information as possible.
%
% WARNING: This function is deprecated, and is now just a call to
% the more more powerful OrderedPosterizeImage(); function.
%
% The format of the OrderedDitherImage method is:
%
% MagickBooleanType OrderedDitherImage(Image *image)
% MagickBooleanType OrderedDitherImageChannel(Image *image,
% const ChannelType channel,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: the channel or channels to be thresholded.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType OrderedDitherImage(Image *image)
{
MagickBooleanType
status;
status=OrderedDitherImageChannel(image,DefaultChannels,&image->exception);
return(status);
}
MagickExport MagickBooleanType OrderedDitherImageChannel(Image *image,
const ChannelType channel,ExceptionInfo *exception)
{
MagickBooleanType
status;
/*
Call the augumented function OrderedPosterizeImage()
*/
status=OrderedPosterizeImageChannel(image,channel,"o8x8",exception);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% O r d e r e d P o s t e r i z e I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% OrderedPosterizeImage() 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 OrderedPosterizeImage method is:
%
% MagickBooleanType OrderedPosterizeImage(Image *image,
% const char *threshold_map,ExceptionInfo *exception)
% MagickBooleanType OrderedPosterizeImageChannel(Image *image,
% const ChannelType channel,const char *threshold_map,
% ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: the channel or channels to be thresholded.
%
% 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 equivelent 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 OrderedPosterizeImage(Image *image,
const char *threshold_map,ExceptionInfo *exception)
{
MagickBooleanType
status;
status=OrderedPosterizeImageChannel(image,DefaultChannels,threshold_map,
exception);
return(status);
}
MagickExport MagickBooleanType OrderedPosterizeImageChannel(Image *image,
const ChannelType channel,const char *threshold_map,ExceptionInfo *exception)
{
#define DitherImageTag "Dither/Image"
CacheView
*image_view;
LongPixelPacket
levels;
MagickBooleanType
status;
MagickOffsetType
progress;
ssize_t
y;
ThresholdMap
*map;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickSignature);
if (threshold_map == (const char *) NULL)
return(MagickTrue);
{
char
token[MaxTextExtent];
register const char
*p;
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) >= MaxTextExtent)
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);
}
}
/* Set channel levels from extra comma separated arguments
Default to 2, the single value given, or individual channel values
*/
#if 1
{ /* parse directly as a comma separated list of integers */
char *p;
p = strchr((char *) threshold_map,',');
if ( p != (char *)NULL && isdigit((int) ((unsigned char) *(++p))) )
levels.index = (unsigned int) strtoul(p, &p, 10);
else
levels.index = 2;
levels.red = ((channel & RedChannel ) != 0) ? levels.index : 0;
levels.green = ((channel & GreenChannel) != 0) ? levels.index : 0;
levels.blue = ((channel & BlueChannel) != 0) ? levels.index : 0;
levels.opacity = ((channel & OpacityChannel) != 0) ? levels.index : 0;
levels.index = ((channel & IndexChannel) != 0
&& (image->colorspace == CMYKColorspace)) ? levels.index : 0;
/* if more than a single number, each channel has a separate value */
if ( p != (char *) NULL && *p == ',' ) {
p=strchr((char *) threshold_map,',');
p++;
if ((channel & RedChannel) != 0)
levels.red = (unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++);
if ((channel & GreenChannel) != 0)
levels.green = (unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++);
if ((channel & BlueChannel) != 0)
levels.blue = (unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++);
if ((channel & IndexChannel) != 0 && image->colorspace == CMYKColorspace)
levels.index=(unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++);
if ((channel & OpacityChannel) != 0)
levels.opacity = (unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++);
}
}
#else
/* Parse level values as a geometry */
/* This difficult!
* How to map GeometryInfo structure elements into
* LongPixelPacket structure elements, but according to channel?
* Note the channels list may skip elements!!!!
* EG -channel BA -ordered-dither map,2,3
* will need to map g.rho -> l.blue, and g.sigma -> l.opacity
* A simpler way is needed, probably converting geometry to a temporary
* array, then using channel to advance the index into ssize_t pixel packet.
*/
#endif
#if 0
printf("DEBUG levels r=%u g=%u b=%u a=%u i=%u\n",
levels.red, levels.green, levels.blue, levels.opacity, levels.index);
#endif
{ /* Do the posterized ordered dithering of the image */
ssize_t
d;
/* d = number of psuedo-level divisions added between color levels */
d = map->divisor-1;
/* reduce levels to levels - 1 */
levels.red = levels.red ? levels.red-1 : 0;
levels.green = levels.green ? levels.green-1 : 0;
levels.blue = levels.blue ? levels.blue-1 : 0;
levels.opacity = levels.opacity ? levels.opacity-1 : 0;
levels.index = levels.index ? levels.index-1 : 0;
if (SetImageStorageClass(image,DirectClass) == MagickFalse)
{
InheritException(exception,&image->exception);
return(MagickFalse);
}
status=MagickTrue;
progress=0;
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(dynamic,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register IndexPacket
*restrict indexes;
register ssize_t
x;
register PixelPacket
*restrict q;
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);
for (x=0; x < (ssize_t) image->columns; x++)
{
register ssize_t
threshold,
t,
l;
/*
Figure out the dither threshold for this pixel
This must be a integer from 1 to map->divisor-1
*/
threshold = map->levels[(x%map->width) +map->width*(y%map->height)];
/* Dither each channel in the image as appropriate
Notes on the integer Math...
total number of divisions = (levels-1)*(divisor-1)+1)
t1 = this colors psuedo_level =
q->red * total_divisions / (QuantumRange+1)
l = posterization level 0..levels
t = dither threshold level 0..divisor-1 NB: 0 only on last
Each color_level is of size QuantumRange / (levels-1)
NB: All input levels and divisor are already had 1 subtracted
Opacity is inverted so 'off' represents transparent.
*/
if (levels.red) {
t = (ssize_t) (QuantumScale*q->red*(levels.red*d+1));
l = t/d; t = t-l*d;
q->red=RoundToQuantum((MagickRealType) ((l+(t >= threshold))*
(MagickRealType) QuantumRange/levels.red));
}
if (levels.green) {
t = (ssize_t) (QuantumScale*q->green*(levels.green*d+1));
l = t/d; t = t-l*d;
q->green=RoundToQuantum((MagickRealType) ((l+(t >= threshold))*
(MagickRealType) QuantumRange/levels.green));
}
if (levels.blue) {
t = (ssize_t) (QuantumScale*q->blue*(levels.blue*d+1));
l = t/d; t = t-l*d;
q->blue=RoundToQuantum((MagickRealType) ((l+(t >= threshold))*
(MagickRealType) QuantumRange/levels.blue));
}
if (levels.opacity) {
t = (ssize_t) ((1.0-QuantumScale*q->opacity)*(levels.opacity*d+1));
l = t/d; t = t-l*d;
q->opacity=RoundToQuantum((MagickRealType) ((1.0-l-(t >= threshold))*
(MagickRealType) QuantumRange/levels.opacity));
}
if (levels.index) {
t = (ssize_t) (QuantumScale*indexes[x]*(levels.index*d+1));
l = t/d; t = t-l*d;
indexes[x]=(IndexPacket) RoundToQuantum((MagickRealType) ((l+
(t>=threshold))*(MagickRealType) QuantumRange/levels.index));
}
q++;
}
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_OrderedPosterizeImageChannel)
#endif
proceed=SetImageProgress(image,DitherImageTag,progress++,image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
}
map=DestroyThresholdMap(map);
return(MagickTrue);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% 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 RandomThresholdImageChannel(Image *image,
% const char *thresholds,ExceptionInfo *exception)
% MagickBooleanType RandomThresholdImageChannel(Image *image,
% const ChannelType channel,const char *thresholds,
% ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: the channel or channels to be thresholded.
%
% o thresholds: a geometry string containing low,high thresholds. If the
% string contains 2x2, 3x3, or 4x4, an ordered dither of order 2, 3, or 4
% is performed instead.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType RandomThresholdImage(Image *image,
const char *thresholds,ExceptionInfo *exception)
{
MagickBooleanType
status;
status=RandomThresholdImageChannel(image,DefaultChannels,thresholds,
exception);
return(status);
}
MagickExport MagickBooleanType RandomThresholdImageChannel(Image *image,
const ChannelType channel,const char *thresholds,ExceptionInfo *exception)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view;
GeometryInfo
geometry_info;
MagickStatusType
flags;
MagickBooleanType
status;
MagickOffsetType
progress;
MagickPixelPacket
threshold;
MagickRealType
min_threshold,
max_threshold;
RandomInfo
**restrict random_info;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickSignature);
if (thresholds == (const char *) NULL)
return(MagickTrue);
GetMagickPixelPacket(image,&threshold);
min_threshold=0.0;
max_threshold=(MagickRealType) QuantumRange;
flags=ParseGeometry(thresholds,&geometry_info);
min_threshold=geometry_info.rho;
max_threshold=geometry_info.sigma;
if ((flags & SigmaValue) == 0)
max_threshold=min_threshold;
if (strchr(thresholds,'%') != (char *) NULL)
{
max_threshold*=(MagickRealType) (0.01*QuantumRange);
min_threshold*=(MagickRealType) (0.01*QuantumRange);
}
else
if (((max_threshold == min_threshold) || (max_threshold == 1)) &&
(min_threshold <= 8))
{
/*
Backward Compatibility -- ordered-dither -- IM v 6.2.9-6.
*/
status=OrderedPosterizeImageChannel(image,channel,thresholds,exception);
return(status);
}
/*
Random threshold image.
*/
status=MagickTrue;
progress=0;
if (channel == AllChannels)
{
if (AcquireImageColormap(image,2) == MagickFalse)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
random_info=AcquireRandomInfoThreadSet();
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(dynamic,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
const int
id = GetOpenMPThreadId();
MagickBooleanType
sync;
register IndexPacket
*restrict indexes;
register ssize_t
x;
register PixelPacket
*restrict q;
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);
for (x=0; x < (ssize_t) image->columns; x++)
{
IndexPacket
index;
MagickRealType
intensity;
intensity=(MagickRealType) PixelIntensityToQuantum(q);
if (intensity < min_threshold)
threshold.index=min_threshold;
else if (intensity > max_threshold)
threshold.index=max_threshold;
else
threshold.index=(MagickRealType)(QuantumRange*
GetPseudoRandomValue(random_info[id]));
index=(IndexPacket) (intensity <= threshold.index ? 0 : 1);
indexes[x]=index;
*q++=image->colormap[(ssize_t) index];
}
sync=SyncCacheViewAuthenticPixels(image_view,exception);
if (sync == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp critical (MagickCore_RandomThresholdImageChannel)
#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);
}
if (SetImageStorageClass(image,DirectClass) == MagickFalse)
{
InheritException(exception,&image->exception);
return(MagickFalse);
}
random_info=AcquireRandomInfoThreadSet();
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(dynamic,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
const int
id = GetOpenMPThreadId();
register IndexPacket
*restrict indexes;
register PixelPacket
*restrict q;
register 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);
for (x=0; x < (ssize_t) image->columns; x++)
{
if ((channel & RedChannel) != 0)
{
if ((MagickRealType) q->red < min_threshold)
threshold.red=min_threshold;
else
if ((MagickRealType) q->red > max_threshold)
threshold.red=max_threshold;
else
threshold.red=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if ((channel & GreenChannel) != 0)
{
if ((MagickRealType) q->green < min_threshold)
threshold.green=min_threshold;
else
if ((MagickRealType) q->green > max_threshold)
threshold.green=max_threshold;
else
threshold.green=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if ((channel & BlueChannel) != 0)
{
if ((MagickRealType) q->blue < min_threshold)
threshold.blue=min_threshold;
else
if ((MagickRealType) q->blue > max_threshold)
threshold.blue=max_threshold;
else
threshold.blue=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if ((channel & OpacityChannel) != 0)
{
if ((MagickRealType) q->opacity < min_threshold)
threshold.opacity=min_threshold;
else
if ((MagickRealType) q->opacity > max_threshold)
threshold.opacity=max_threshold;
else
threshold.opacity=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
{
if ((MagickRealType) indexes[x] < min_threshold)
threshold.index=min_threshold;
else
if ((MagickRealType) indexes[x] > max_threshold)
threshold.index=max_threshold;
else
threshold.index=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if ((channel & RedChannel) != 0)
q->red=(Quantum) ((MagickRealType) q->red <= threshold.red ? 0 :
QuantumRange);
if ((channel & GreenChannel) != 0)
q->green=(Quantum) ((MagickRealType) q->green <= threshold.green ? 0 :
QuantumRange);
if ((channel & BlueChannel) != 0)
q->blue=(Quantum) ((MagickRealType) q->blue <= threshold.blue ? 0 :
QuantumRange);
if ((channel & OpacityChannel) != 0)
q->opacity=(Quantum) ((MagickRealType) q->opacity <= threshold.opacity ?
0 : QuantumRange);
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
indexes[x]=(IndexPacket) ((MagickRealType) indexes[x] <=
threshold.index ? 0 : QuantumRange);
q++;
}
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_RandomThresholdImageChannel)
#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)
% MagickBooleanType WhiteThresholdImageChannel(Image *image,
% const ChannelType channel,const char *threshold,
% ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: the channel or channels to be thresholded.
%
% o threshold: Define the threshold value.
%
% o exception: return any errors or warnings in this structure.
%
*/
MagickExport MagickBooleanType WhiteThresholdImage(Image *image,
const char *threshold)
{
MagickBooleanType
status;
status=WhiteThresholdImageChannel(image,DefaultChannels,threshold,
&image->exception);
return(status);
}
MagickExport MagickBooleanType WhiteThresholdImageChannel(Image *image,
const ChannelType channel,const char *thresholds,ExceptionInfo *exception)
{
#define ThresholdImageTag "Threshold/Image"
CacheView
*image_view;
GeometryInfo
geometry_info;
MagickBooleanType
status;
MagickPixelPacket
threshold;
MagickOffsetType
progress;
MagickStatusType
flags;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (thresholds == (const char *) NULL)
return(MagickTrue);
if (SetImageStorageClass(image,DirectClass) == MagickFalse)
return(MagickFalse);
flags=ParseGeometry(thresholds,&geometry_info);
GetMagickPixelPacket(image,&threshold);
threshold.red=geometry_info.rho;
threshold.green=geometry_info.sigma;
if ((flags & SigmaValue) == 0)
threshold.green=threshold.red;
threshold.blue=geometry_info.xi;
if ((flags & XiValue) == 0)
threshold.blue=threshold.red;
threshold.opacity=geometry_info.psi;
if ((flags & PsiValue) == 0)
threshold.opacity=threshold.red;
threshold.index=geometry_info.chi;
if ((flags & ChiValue) == 0)
threshold.index=threshold.red;
if ((flags & PercentValue) != 0)
{
threshold.red*=(QuantumRange/100.0);
threshold.green*=(QuantumRange/100.0);
threshold.blue*=(QuantumRange/100.0);
threshold.opacity*=(QuantumRange/100.0);
threshold.index*=(QuantumRange/100.0);
}
/*
White threshold image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireCacheView(image);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(dynamic,4) shared(progress,status)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
register IndexPacket
*restrict indexes;
register ssize_t
x;
register PixelPacket
*restrict q;
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);
for (x=0; x < (ssize_t) image->columns; x++)
{
if (channel != DefaultChannels)
{
if (PixelIntensity(q) > MagickPixelIntensity(&threshold))
{
q->red=(Quantum) QuantumRange;
q->green=(Quantum) QuantumRange;
q->blue=(Quantum) QuantumRange;
if (image->colorspace == CMYKColorspace)
indexes[x]=(Quantum) QuantumRange;
}
}
else
{
if (((channel & RedChannel) != 0) &&
((MagickRealType) q->red > threshold.red))
q->red=(Quantum) QuantumRange;
if (((channel & GreenChannel) != 0) &&
((MagickRealType) q->green > threshold.green))
q->green=(Quantum) QuantumRange;
if (((channel & BlueChannel) != 0) &&
((MagickRealType) q->blue > threshold.blue))
q->blue=(Quantum) QuantumRange;
if (((channel & OpacityChannel) != 0) &&
((MagickRealType) q->opacity > threshold.opacity))
q->opacity=(Quantum) QuantumRange;
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace) &&
((MagickRealType) indexes[x] > threshold.index))
indexes[x]=(Quantum) QuantumRange;
}
q++;
}
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_WhiteThresholdImageChannel)
#endif
proceed=SetImageProgress(image,ThresholdImageTag,progress++,
image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
return(status);
}