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