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/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% 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 1999-2021 ImageMagick Studio LLC, a non-profit organization %
% dedicated to making software imaging solutions freely available. %
% %
% You may not use this file except in compliance with the License. You may %
% obtain a copy of the License at %
% %
% https://imagemagick.org/script/license.php %
% %
% Unless required by applicable law or agreed to in writing, software %
% distributed under the License is distributed on an "AS IS" BASIS, %
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
% See the License for the specific language governing permissions and %
% limitations under the License. %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
%
*/
/*
Include declarations.
*/
#include "magick/studio.h"
#include "magick/artifact.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/colorspace-private.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/property.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;
};
/*
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>";
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% 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 == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(exception != (ExceptionInfo *) NULL);
assert(exception->signature == MagickCoreSignature);
threshold_image=CloneImage(image,0,0,MagickTrue,exception);
if (threshold_image == (Image *) NULL)
return((Image *) NULL);
if ((width == 0) || (height == 0))
return(threshold_image);
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=AcquireVirtualCacheView(image,exception);
threshold_view=AcquireAuthenticCacheView(threshold_image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,threshold_image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
MagickBooleanType
sync;
MagickPixelPacket
channel_bias,
channel_sum;
const IndexPacket
*magick_restrict indexes;
const PixelPacket
*magick_restrict p,
*magick_restrict r;
IndexPacket
*magick_restrict threshold_indexes;
PixelPacket
*magick_restrict q;
ssize_t
x;
ssize_t
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=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);
channel_bias=zero;
channel_sum=zero;
r=p;
for (v=0; v < (ssize_t) height; v++)
{
for (u=0; u < (ssize_t) width; u++)
{
if (u == (ssize_t) (width-1))
{
channel_bias.red+=r[u].red;
channel_bias.green+=r[u].green;
channel_bias.blue+=r[u].blue;
channel_bias.opacity+=r[u].opacity;
if (image->colorspace == CMYKColorspace)
channel_bias.index=(MagickRealType)
GetPixelIndex(indexes+(r-p)+u);
}
channel_sum.red+=r[u].red;
channel_sum.green+=r[u].green;
channel_sum.blue+=r[u].blue;
channel_sum.opacity+=r[u].opacity;
if (image->colorspace == CMYKColorspace)
channel_sum.index=(MagickRealType) GetPixelIndex(indexes+(r-p)+u);
}
r+=image->columns+width;
}
for (x=0; x < (ssize_t) image->columns; x++)
{
MagickPixelPacket
mean;
mean=zero;
r=p;
channel_sum.red-=channel_bias.red;
channel_sum.green-=channel_bias.green;
channel_sum.blue-=channel_bias.blue;
channel_sum.opacity-=channel_bias.opacity;
channel_sum.index-=channel_bias.index;
channel_bias=zero;
for (v=0; v < (ssize_t) height; v++)
{
channel_bias.red+=r[0].red;
channel_bias.green+=r[0].green;
channel_bias.blue+=r[0].blue;
channel_bias.opacity+=r[0].opacity;
if (image->colorspace == CMYKColorspace)
channel_bias.index=(MagickRealType) GetPixelIndex(indexes+x+(r-p)+0);
channel_sum.red+=r[width-1].red;
channel_sum.green+=r[width-1].green;
channel_sum.blue+=r[width-1].blue;
channel_sum.opacity+=r[width-1].opacity;
if (image->colorspace == CMYKColorspace)
channel_sum.index=(MagickRealType) GetPixelIndex(indexes+x+(r-p)+
width-1);
r+=image->columns+width;
}
mean.red=(MagickRealType) (channel_sum.red/number_pixels+offset);
mean.green=(MagickRealType) (channel_sum.green/number_pixels+offset);
mean.blue=(MagickRealType) (channel_sum.blue/number_pixels+offset);
mean.opacity=(MagickRealType) (channel_sum.opacity/number_pixels+offset);
if (image->colorspace == CMYKColorspace)
mean.index=(MagickRealType) (channel_sum.index/number_pixels+offset);
SetPixelRed(q,((MagickRealType) GetPixelRed(q) <= mean.red) ?
0 : QuantumRange);
SetPixelGreen(q,((MagickRealType) GetPixelGreen(q) <= mean.green) ?
0 : QuantumRange);
SetPixelBlue(q,((MagickRealType) GetPixelBlue(q) <= mean.blue) ?
0 : QuantumRange);
SetPixelOpacity(q,((MagickRealType) GetPixelOpacity(q) <= mean.opacity) ?
0 : QuantumRange);
if (image->colorspace == CMYKColorspace)
SetPixelIndex(threshold_indexes+x,(((MagickRealType) GetPixelIndex(
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 atomic
#endif
progress++;
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);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% A u t o T h r e s h o l d I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% AutoThresholdImage() automatically performs image thresholding
% dependent on which method you specify.
%
% The format of the AutoThresholdImage method is:
%
% MagickBooleanType AutoThresholdImage(Image *image,
% const AutoThresholdMethod method,ExceptionInfo *exception)
%
% A description of each parameter follows:
%
% o image: The image to auto-threshold.
%
% o method: choose from Kapur, OTSU, or Triangle.
%
% o exception: return any errors or warnings in this structure.
%
*/
static double KapurThreshold(const Image *image,const double *histogram,
ExceptionInfo *exception)
{
#define MaxIntensity 255
double
*black_entropy,
*cumulative_histogram,
entropy,
epsilon,
maximum_entropy,
*white_entropy;
ssize_t
i,
j;
size_t
threshold;
/*
Compute optimal threshold from the entopy of the histogram.
*/
cumulative_histogram=(double *) AcquireQuantumMemory(MaxIntensity+1UL,
sizeof(*cumulative_histogram));
black_entropy=(double *) AcquireQuantumMemory(MaxIntensity+1UL,
sizeof(*black_entropy));
white_entropy=(double *) AcquireQuantumMemory(MaxIntensity+1UL,
sizeof(*white_entropy));
if ((cumulative_histogram == (double *) NULL) ||
(black_entropy == (double *) NULL) || (white_entropy == (double *) NULL))
{
if (white_entropy != (double *) NULL)
white_entropy=(double *) RelinquishMagickMemory(white_entropy);
if (black_entropy != (double *) NULL)
black_entropy=(double *) RelinquishMagickMemory(black_entropy);
if (cumulative_histogram != (double *) NULL)
cumulative_histogram=(double *)
RelinquishMagickMemory(cumulative_histogram);
(void) ThrowMagickException(exception,GetMagickModule(),
ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
return(-1.0);
}
/*
Entropy for black and white parts of the histogram.
*/
cumulative_histogram[0]=histogram[0];
for (i=1; i <= MaxIntensity; i++)
cumulative_histogram[i]=cumulative_histogram[i-1]+histogram[i];
epsilon=MagickMinimumValue;
for (j=0; j <= MaxIntensity; j++)
{
/*
Black entropy.
*/
black_entropy[j]=0.0;
if (cumulative_histogram[j] > epsilon)
{
entropy=0.0;
for (i=0; i <= j; i++)
if (histogram[i] > epsilon)
entropy-=histogram[i]/cumulative_histogram[j]*
log(histogram[i]/cumulative_histogram[j]);
black_entropy[j]=entropy;
}
/*
White entropy.
*/
white_entropy[j]=0.0;
if ((1.0-cumulative_histogram[j]) > epsilon)
{
entropy=0.0;
for (i=j+1; i <= MaxIntensity; i++)
if (histogram[i] > epsilon)
entropy-=histogram[i]/(1.0-cumulative_histogram[j])*
log(histogram[i]/(1.0-cumulative_histogram[j]));
white_entropy[j]=entropy;
}
}
/*
Find histogram bin with maximum entropy.
*/
maximum_entropy=black_entropy[0]+white_entropy[0];
threshold=0;
for (j=1; j <= MaxIntensity; j++)
if ((black_entropy[j]+white_entropy[j]) > maximum_entropy)
{
maximum_entropy=black_entropy[j]+white_entropy[j];
threshold=(size_t) j;
}
/*
Free resources.
*/
white_entropy=(double *) RelinquishMagickMemory(white_entropy);
black_entropy=(double *) RelinquishMagickMemory(black_entropy);
cumulative_histogram=(double *) RelinquishMagickMemory(cumulative_histogram);
return(100.0*threshold/MaxIntensity);
}
static double OTSUThreshold(const Image *image,const double *histogram,
ExceptionInfo *exception)
{
double
max_sigma,
*myu,
*omega,
*probability,
*sigma,
threshold;
ssize_t
i;
/*
Compute optimal threshold from maximization of inter-class variance.
*/
myu=(double *) AcquireQuantumMemory(MaxIntensity+1UL,sizeof(*myu));
omega=(double *) AcquireQuantumMemory(MaxIntensity+1UL,sizeof(*omega));
probability=(double *) AcquireQuantumMemory(MaxIntensity+1UL,
sizeof(*probability));
sigma=(double *) AcquireQuantumMemory(MaxIntensity+1UL,sizeof(*sigma));
if ((myu == (double *) NULL) || (omega == (double *) NULL) ||
(probability == (double *) NULL) || (sigma == (double *) NULL))
{
if (sigma != (double *) NULL)
sigma=(double *) RelinquishMagickMemory(sigma);
if (probability != (double *) NULL)
probability=(double *) RelinquishMagickMemory(probability);
if (omega != (double *) NULL)
omega=(double *) RelinquishMagickMemory(omega);
if (myu != (double *) NULL)
myu=(double *) RelinquishMagickMemory(myu);
(void) ThrowMagickException(exception,GetMagickModule(),
ResourceLimitError,"MemoryAllocationFailed","`%s'",image->filename);
return(-1.0);
}
/*
Calculate probability density.
*/
for (i=0; i <= (ssize_t) MaxIntensity; i++)
probability[i]=histogram[i];
/*
Generate probability of graylevels and mean value for separation.
*/
omega[0]=probability[0];
myu[0]=0.0;
for (i=1; i <= (ssize_t) MaxIntensity; i++)
{
omega[i]=omega[i-1]+probability[i];
myu[i]=myu[i-1]+i*probability[i];
}
/*
Sigma maximization: inter-class variance and compute optimal threshold.
*/
threshold=0;
max_sigma=0.0;
for (i=0; i < (ssize_t) MaxIntensity; i++)
{
sigma[i]=0.0;
if ((omega[i] != 0.0) && (omega[i] != 1.0))
sigma[i]=pow(myu[MaxIntensity]*omega[i]-myu[i],2.0)/(omega[i]*(1.0-
omega[i]));
if (sigma[i] > max_sigma)
{
max_sigma=sigma[i];
threshold=(double) i;
}
}
/*
Free resources.
*/
myu=(double *) RelinquishMagickMemory(myu);
omega=(double *) RelinquishMagickMemory(omega);
probability=(double *) RelinquishMagickMemory(probability);
sigma=(double *) RelinquishMagickMemory(sigma);
return(100.0*threshold/MaxIntensity);
}
static double TriangleThreshold(const Image *image,const double *histogram)
{
double
a,
b,
c,
count,
distance,
inverse_ratio,
max_distance,
segment,
x1,
x2,
y1,
y2;
ssize_t
i;
ssize_t
end,
max,
start,
threshold;
/*
Compute optimal threshold with triangle algorithm.
*/
magick_unreferenced(image);
start=0; /* find start bin, first bin not zero count */
for (i=0; i <= (ssize_t) MaxIntensity; i++)
if (histogram[i] > 0.0)
{
start=i;
break;
}
end=0; /* find end bin, last bin not zero count */
for (i=(ssize_t) MaxIntensity; i >= 0; i--)
if (histogram[i] > 0.0)
{
end=i;
break;
}
max=0; /* find max bin, bin with largest count */
count=0.0;
for (i=0; i <= (ssize_t) MaxIntensity; i++)
if (histogram[i] > count)
{
max=i;
count=histogram[i];
}
/*
Compute threshold at split point.
*/
x1=(double) max;
y1=histogram[max];
x2=(double) end;
if ((max-start) >= (end-max))
x2=(double) start;
y2=0.0;
a=y1-y2;
b=x2-x1;
c=(-1.0)*(a*x1+b*y1);
inverse_ratio=1.0/sqrt(a*a+b*b+c*c);
threshold=0;
max_distance=0.0;
if (x2 == (double) start)
for (i=start; i < max; i++)
{
segment=inverse_ratio*(a*i+b*histogram[i]+c);
distance=sqrt(segment*segment);
if ((distance > max_distance) && (segment > 0.0))
{
threshold=i;
max_distance=distance;
}
}
else
for (i=end; i > max; i--)
{
segment=inverse_ratio*(a*i+b*histogram[i]+c);
distance=sqrt(segment*segment);
if ((distance > max_distance) && (segment < 0.0))
{
threshold=i;
max_distance=distance;
}
}
return(100.0*threshold/MaxIntensity);
}
MagickExport MagickBooleanType AutoThresholdImage(Image *image,
const AutoThresholdMethod method,ExceptionInfo *exception)
{
CacheView
*image_view;
char
property[MagickPathExtent];
const char
*artifact;
double
gamma,
*histogram,
sum,
threshold;
MagickBooleanType
status;
ssize_t
i;
ssize_t
y;
/*
Form histogram.
*/
assert(image != (Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
histogram=(double *) AcquireQuantumMemory(MaxIntensity+1UL,
sizeof(*histogram));
if (histogram == (double *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
status=MagickTrue;
(void) memset(histogram,0,(MaxIntensity+1UL)*sizeof(*histogram));
image_view=AcquireVirtualCacheView(image,exception);
for (y=0; y < (ssize_t) image->rows; y++)
{
const PixelPacket
*magick_restrict p;
ssize_t
x;
p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
if (p == (const PixelPacket *) NULL)
break;
for (x=0; x < (ssize_t) image->columns; x++)
{
double intensity = GetPixelIntensity(image,p);
histogram[ScaleQuantumToChar(ClampToQuantum(intensity))]++;
p++;
}
}
image_view=DestroyCacheView(image_view);
/*
Normalize histogram.
*/
sum=0.0;
for (i=0; i <= (ssize_t) MaxIntensity; i++)
sum+=histogram[i];
gamma=PerceptibleReciprocal(sum);
for (i=0; i <= (ssize_t) MaxIntensity; i++)
histogram[i]=gamma*histogram[i];
/*
Discover threshold from histogram.
*/
switch (method)
{
case KapurThresholdMethod:
{
threshold=KapurThreshold(image,histogram,exception);
break;
}
case OTSUThresholdMethod:
default:
{
threshold=OTSUThreshold(image,histogram,exception);
break;
}
case TriangleThresholdMethod:
{
threshold=TriangleThreshold(image,histogram);
break;
}
}
histogram=(double *) RelinquishMagickMemory(histogram);
if (threshold < 0.0)
status=MagickFalse;
if (status == MagickFalse)
return(MagickFalse);
/*
Threshold image.
*/
(void) FormatLocaleString(property,MagickPathExtent,"%g%%",threshold);
(void) SetImageProperty(image,"auto-threshold:threshold",property);
artifact=GetImageArtifact(image,"threshold:verbose");
if (IsStringTrue(artifact) != MagickFalse)
(void) FormatLocaleFile(stdout,"%.*g%%\n",GetMagickPrecision(),threshold);
return(BilevelImage(image,QuantumRange*threshold/100.0));
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% 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 == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (SetImageStorageClass(image,DirectClass) == MagickFalse)
return(MagickFalse);
if (IsGrayColorspace(image->colorspace) == MagickFalse)
(void) SetImageColorspace(image,sRGBColorspace);
/*
Bilevel threshold image.
*/
status=MagickTrue;
progress=0;
exception=(&image->exception);
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
ssize_t
x;
PixelPacket
*magick_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 & SyncChannels) != 0)
{
for (x=0; x < (ssize_t) image->columns; x++)
{
SetPixelRed(q,GetPixelIntensity(image,q) <= threshold ? 0 :
QuantumRange);
SetPixelGreen(q,GetPixelRed(q));
SetPixelBlue(q,GetPixelRed(q));
q++;
}
}
else
for (x=0; x < (ssize_t) image->columns; x++)
{
if ((channel & RedChannel) != 0)
SetPixelRed(q,(MagickRealType) GetPixelRed(q) <= threshold ? 0 :
QuantumRange);
if ((channel & GreenChannel) != 0)
SetPixelGreen(q,(MagickRealType) GetPixelGreen(q) <= threshold ? 0 :
QuantumRange);
if ((channel & BlueChannel) != 0)
SetPixelBlue(q,(MagickRealType) GetPixelBlue(q) <= threshold ? 0 :
QuantumRange);
if ((channel & OpacityChannel) != 0)
{
if (image->matte == MagickFalse)
SetPixelOpacity(q,(MagickRealType) GetPixelOpacity(q) <=
threshold ? 0 : QuantumRange);
else
SetPixelAlpha(q,(MagickRealType) GetPixelAlpha(q) <= threshold ?
OpaqueOpacity : TransparentOpacity);
}
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
SetPixelIndex(indexes+x,(MagickRealType) GetPixelIndex(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 atomic
#endif
progress++;
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 == MagickCoreSignature);
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*=(MagickRealType) (QuantumRange/100.0);
threshold.green*=(MagickRealType) (QuantumRange/100.0);
threshold.blue*=(MagickRealType) (QuantumRange/100.0);
threshold.opacity*=(MagickRealType) (QuantumRange/100.0);
threshold.index*=(MagickRealType) (QuantumRange/100.0);
}
if ((IsMagickGray(&threshold) == MagickFalse) &&
(IsGrayColorspace(image->colorspace) != MagickFalse))
(void) SetImageColorspace(image,sRGBColorspace);
/*
Black threshold image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
ssize_t
x;
PixelPacket
*magick_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) &&
((MagickRealType) GetPixelRed(q) < threshold.red))
SetPixelRed(q,0);
if (((channel & GreenChannel) != 0) &&
((MagickRealType) GetPixelGreen(q) < threshold.green))
SetPixelGreen(q,0);
if (((channel & BlueChannel) != 0) &&
((MagickRealType) GetPixelBlue(q) < threshold.blue))
SetPixelBlue(q,0);
if (((channel & OpacityChannel) != 0) &&
((MagickRealType) GetPixelOpacity(q) < threshold.opacity))
SetPixelOpacity(q,0);
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace) &&
((MagickRealType) GetPixelIndex(indexes+x) < threshold.index))
SetPixelIndex(indexes+x,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 atomic
#endif
progress++;
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 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.
%
*/
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 == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (image->storage_class == PseudoClass)
{
ssize_t
i;
PixelPacket
*magick_restrict q;
q=image->colormap;
for (i=0; i < (ssize_t) image->colors; i++)
{
SetPixelRed(q,ClampPixel((MagickRealType) GetPixelRed(q)));
SetPixelGreen(q,ClampPixel((MagickRealType) GetPixelGreen(q)));
SetPixelBlue(q,ClampPixel((MagickRealType) GetPixelBlue(q)));
SetPixelOpacity(q,ClampPixel((MagickRealType) GetPixelOpacity(q)));
q++;
}
return(SyncImage(image));
}
/*
Clamp image.
*/
status=MagickTrue;
progress=0;
exception=(&image->exception);
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
ssize_t
x;
PixelPacket
*magick_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)
SetPixelRed(q,ClampPixel((MagickRealType) GetPixelRed(q)));
if ((channel & GreenChannel) != 0)
SetPixelGreen(q,ClampPixel((MagickRealType) GetPixelGreen(q)));
if ((channel & BlueChannel) != 0)
SetPixelBlue(q,ClampPixel((MagickRealType) GetPixelBlue(q)));
if ((channel & OpacityChannel) != 0)
SetPixelOpacity(q,ClampPixel((MagickRealType) GetPixelOpacity(q)));
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
SetPixelIndex(indexes+x,ClampPixel((MagickRealType) GetPixelIndex(
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 atomic
#endif
progress++;
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
*attribute,
*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) )
{
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);
}
/*
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 attributeibutes.
*/
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);
}
/*
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");
{
char
*p;
ssize_t
i;
/*
Parse levels into integer array.
*/
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=GetThresholdMapFile(MinimalThresholdMap,"built-in",map_id,exception);
if (map != (ThresholdMap *) NULL)
return(map);
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);
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) FormatLocaleFile(file,"%-16s %-12s %s\n","Map","Alias","Description");
(void) FormatLocaleFile(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) 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() 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 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 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 == 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);
{
char
token[MaxTextExtent];
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-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);
}
}
/* 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=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
ssize_t
x;
PixelPacket
*magick_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++)
{
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*GetPixelRed(q)*(levels.red*d+1));
l = t/d; t = t-l*d;
SetPixelRed(q,ClampToQuantum((MagickRealType)
((l+(t >= threshold))*(MagickRealType) QuantumRange/levels.red)));
}
if (levels.green) {
t = (ssize_t) (QuantumScale*GetPixelGreen(q)*
(levels.green*d+1));
l = t/d; t = t-l*d;
SetPixelGreen(q,ClampToQuantum((MagickRealType)
((l+(t >= threshold))*(MagickRealType) QuantumRange/levels.green)));
}
if (levels.blue) {
t = (ssize_t) (QuantumScale*GetPixelBlue(q)*
(levels.blue*d+1));
l = t/d; t = t-l*d;
SetPixelBlue(q,ClampToQuantum((MagickRealType)
((l+(t >= threshold))*(MagickRealType) QuantumRange/levels.blue)));
}
if (levels.opacity) {
t = (ssize_t) ((1.0-QuantumScale*GetPixelOpacity(q))*
(levels.opacity*d+1));
l = t/d; t = t-l*d;
SetPixelOpacity(q,ClampToQuantum((MagickRealType)
((1.0-l-(t >= threshold))*(MagickRealType) QuantumRange/
levels.opacity)));
}
if (levels.index) {
t = (ssize_t) (QuantumScale*GetPixelIndex(indexes+x)*
(levels.index*d+1));
l = t/d; t = t-l*d;
SetPixelIndex(indexes+x,ClampToQuantum((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 atomic
#endif
progress++;
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 PerceptibleImageChannel method is:
%
% MagickBooleanType PerceptibleImage(Image *image,const double epsilon)
% MagickBooleanType PerceptibleImageChannel(Image *image,
% const ChannelType channel,const double epsilon)
%
% A description of each parameter follows:
%
% o image: the image.
%
% o channel: the channel type.
%
% o epsilon: the epsilon threshold (e.g. 1.0e-9).
%
*/
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)
{
MagickBooleanType
status;
status=PerceptibleImageChannel(image,DefaultChannels,epsilon);
return(status);
}
MagickExport MagickBooleanType PerceptibleImageChannel(Image *image,
const ChannelType channel,const double epsilon)
{
#define PerceptibleImageTag "Perceptible/Image"
CacheView
*image_view;
ExceptionInfo
*exception;
MagickBooleanType
status;
MagickOffsetType
progress;
ssize_t
y;
assert(image != (Image *) NULL);
assert(image->signature == MagickCoreSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (image->storage_class == PseudoClass)
{
ssize_t
i;
PixelPacket
*magick_restrict q;
q=image->colormap;
for (i=0; i < (ssize_t) image->colors; i++)
{
SetPixelRed(q,PerceptibleThreshold(GetPixelRed(q),epsilon));
SetPixelGreen(q,PerceptibleThreshold(GetPixelGreen(q),epsilon));
SetPixelBlue(q,PerceptibleThreshold(GetPixelBlue(q),epsilon));
SetPixelOpacity(q,PerceptibleThreshold(GetPixelOpacity(q),epsilon));
q++;
}
return(SyncImage(image));
}
/*
Perceptible image.
*/
status=MagickTrue;
progress=0;
exception=(&image->exception);
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
ssize_t
x;
PixelPacket
*magick_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)
SetPixelRed(q,PerceptibleThreshold(GetPixelRed(q),epsilon));
if ((channel & GreenChannel) != 0)
SetPixelGreen(q,PerceptibleThreshold(GetPixelGreen(q),epsilon));
if ((channel & BlueChannel) != 0)
SetPixelBlue(q,PerceptibleThreshold(GetPixelBlue(q),epsilon));
if ((channel & OpacityChannel) != 0)
SetPixelOpacity(q,PerceptibleThreshold(GetPixelOpacity(q),epsilon));
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
SetPixelIndex(indexes+x,PerceptibleThreshold(GetPixelIndex(indexes+x),
epsilon));
q++;
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
if (image->progress_monitor != (MagickProgressMonitor) NULL)
{
MagickBooleanType
proceed;
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp atomic
#endif
progress++;
proceed=SetImageProgress(image,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 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
**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 (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 == CompositeChannels)
{
if (AcquireImageColormap(image,2) == MagickFalse)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
random_info=AcquireRandomInfoThreadSet();
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
key=GetRandomSecretKey(random_info[0]);
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,key == ~0UL)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
const int
id = GetOpenMPThreadId();
MagickBooleanType
sync;
IndexPacket
*magick_restrict indexes;
ssize_t
x;
PixelPacket
*magick_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=GetPixelIntensity(image,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);
SetPixelIndex(indexes+x,index);
SetPixelRGBO(q,image->colormap+(ssize_t) index);
q++;
}
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 atomic
#endif
progress++;
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=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
key=GetRandomSecretKey(random_info[0]);
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,key == ~0UL)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
const int
id = GetOpenMPThreadId();
IndexPacket
*magick_restrict indexes;
PixelPacket
*magick_restrict q;
ssize_t
x;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
indexes=GetCacheViewAuthenticIndexQueue(image_view);
for (x=0; x < (ssize_t) image->columns; x++)
{
if ((channel & RedChannel) != 0)
{
if ((MagickRealType) GetPixelRed(q) < min_threshold)
threshold.red=min_threshold;
else
if ((MagickRealType) GetPixelRed(q) > max_threshold)
threshold.red=max_threshold;
else
threshold.red=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if ((channel & GreenChannel) != 0)
{
if ((MagickRealType) GetPixelGreen(q) < min_threshold)
threshold.green=min_threshold;
else
if ((MagickRealType) GetPixelGreen(q) > max_threshold)
threshold.green=max_threshold;
else
threshold.green=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if ((channel & BlueChannel) != 0)
{
if ((MagickRealType) GetPixelBlue(q) < min_threshold)
threshold.blue=min_threshold;
else
if ((MagickRealType) GetPixelBlue(q) > max_threshold)
threshold.blue=max_threshold;
else
threshold.blue=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if ((channel & OpacityChannel) != 0)
{
if ((MagickRealType) GetPixelOpacity(q) < min_threshold)
threshold.opacity=min_threshold;
else
if ((MagickRealType) GetPixelOpacity(q) > max_threshold)
threshold.opacity=max_threshold;
else
threshold.opacity=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
{
if ((MagickRealType) GetPixelIndex(indexes+x) < min_threshold)
threshold.index=min_threshold;
else
if ((MagickRealType) GetPixelIndex(indexes+x) > max_threshold)
threshold.index=max_threshold;
else
threshold.index=(MagickRealType) (QuantumRange*
GetPseudoRandomValue(random_info[id]));
}
if ((channel & RedChannel) != 0)
SetPixelRed(q,(MagickRealType) GetPixelRed(q) <= threshold.red ?
0 : QuantumRange);
if ((channel & GreenChannel) != 0)
SetPixelGreen(q,(MagickRealType) GetPixelGreen(q) <= threshold.green ?
0 : QuantumRange);
if ((channel & BlueChannel) != 0)
SetPixelBlue(q,(MagickRealType) GetPixelBlue(q) <= threshold.blue ?
0 : QuantumRange);
if ((channel & OpacityChannel) != 0)
SetPixelOpacity(q,(MagickRealType) GetPixelOpacity(q) <=
threshold.opacity ? 0 : QuantumRange);
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace))
SetPixelIndex(indexes+x,(MagickRealType) GetPixelIndex(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 atomic
#endif
progress++;
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;
MagickOffsetType
progress;
MagickPixelPacket
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) == 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*=(MagickRealType) (QuantumRange/100.0);
threshold.green*=(MagickRealType) (QuantumRange/100.0);
threshold.blue*=(MagickRealType) (QuantumRange/100.0);
threshold.opacity*=(MagickRealType) (QuantumRange/100.0);
threshold.index*=(MagickRealType) (QuantumRange/100.0);
}
if ((IsMagickGray(&threshold) == MagickFalse) &&
(IsGrayColorspace(image->colorspace) != MagickFalse))
(void) SetImageColorspace(image,sRGBColorspace);
/*
White threshold image.
*/
status=MagickTrue;
progress=0;
image_view=AcquireAuthenticCacheView(image,exception);
#if defined(MAGICKCORE_OPENMP_SUPPORT)
#pragma omp parallel for schedule(static) shared(progress,status) \
magick_number_threads(image,image,image->rows,1)
#endif
for (y=0; y < (ssize_t) image->rows; y++)
{
IndexPacket
*magick_restrict indexes;
ssize_t
x;
PixelPacket
*magick_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) &&
((MagickRealType) GetPixelRed(q) > threshold.red))
SetPixelRed(q,QuantumRange);
if (((channel & GreenChannel) != 0) &&
((MagickRealType) GetPixelGreen(q) > threshold.green))
SetPixelGreen(q,QuantumRange);
if (((channel & BlueChannel) != 0) &&
((MagickRealType) GetPixelBlue(q) > threshold.blue))
SetPixelBlue(q,QuantumRange);
if (((channel & OpacityChannel) != 0) &&
((MagickRealType) GetPixelOpacity(q) > threshold.opacity))
SetPixelOpacity(q,QuantumRange);
if (((channel & IndexChannel) != 0) &&
(image->colorspace == CMYKColorspace) &&
((MagickRealType) GetPixelIndex(indexes+x)) > threshold.index)
SetPixelIndex(indexes+x,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 atomic
#endif
progress++;
proceed=SetImageProgress(image,ThresholdImageTag,progress,image->rows);
if (proceed == MagickFalse)
status=MagickFalse;
}
}
image_view=DestroyCacheView(image_view);
return(status);
}
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