/* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % 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 1999-2017 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://www.imagemagick.org/script/license.php % % % % Unless required by applicable law or agreed to in writing, software % % distributed under the License is distributed on an "AS IS" BASIS, % % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. % % See the License for the specific language governing permissions and % % limitations under the License. % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % */ /* Include declarations. */ #include "MagickCore/studio.h" #include "MagickCore/property.h" #include "MagickCore/blob.h" #include "MagickCore/cache-view.h" #include "MagickCore/color.h" #include "MagickCore/color-private.h" #include "MagickCore/colormap.h" #include "MagickCore/colorspace.h" #include "MagickCore/colorspace-private.h" #include "MagickCore/configure.h" #include "MagickCore/constitute.h" #include "MagickCore/decorate.h" #include "MagickCore/draw.h" #include "MagickCore/enhance.h" #include "MagickCore/exception.h" #include "MagickCore/exception-private.h" #include "MagickCore/effect.h" #include "MagickCore/fx.h" #include "MagickCore/gem.h" #include "MagickCore/geometry.h" #include "MagickCore/image-private.h" #include "MagickCore/list.h" #include "MagickCore/log.h" #include "MagickCore/memory_.h" #include "MagickCore/monitor.h" #include "MagickCore/monitor-private.h" #include "MagickCore/montage.h" #include "MagickCore/option.h" #include "MagickCore/pixel-accessor.h" #include "MagickCore/pixel-private.h" #include "MagickCore/quantize.h" #include "MagickCore/quantum.h" #include "MagickCore/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. */ static const char *MinimalThresholdMap = "" "" " " " Threshold 1x1 (non-dither)" " " " 1" " " " " " " " Checkerboard 2x1 (dither)" " " " 1 2" " 2 1" " " " " ""; /* Forward declarations. */ static ThresholdMap *GetThresholdMapFile(const char *,const char *,const char *,ExceptionInfo *); /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % A d a p t i v e T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % AdaptiveThresholdImage() selects an individual threshold for each pixel % based on the range of intensity values in its local neighborhood. This % allows for thresholding of an image whose global intensity histogram % doesn't contain distinctive peaks. % % The format of the AdaptiveThresholdImage method is: % % Image *AdaptiveThresholdImage(const Image *image,const size_t width, % const size_t height,const double bias,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o width: the width of the local neighborhood. % % o height: the height of the local neighborhood. % % o bias: the mean bias. % % o exception: return any errors or warnings in this structure. % */ MagickExport Image *AdaptiveThresholdImage(const Image *image, const size_t width,const size_t height,const double bias, ExceptionInfo *exception) { #define AdaptiveThresholdImageTag "AdaptiveThreshold/Image" CacheView *image_view, *threshold_view; Image *threshold_image; MagickBooleanType status; MagickOffsetType progress; MagickSizeType number_pixels; ssize_t y; /* Initialize threshold image attributes. */ assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickCoreSignature); threshold_image=CloneImage(image,image->columns,image->rows,MagickTrue, exception); if (threshold_image == (Image *) NULL) return((Image *) NULL); status=SetImageStorageClass(threshold_image,DirectClass,exception); if (status == MagickFalse) { threshold_image=DestroyImage(threshold_image); return((Image *) NULL); } /* Threshold image. */ status=MagickTrue; progress=0; number_pixels=(MagickSizeType) width*height; image_view=AcquireVirtualCacheView(image,exception); threshold_view=AcquireAuthenticCacheView(threshold_image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static,4) shared(progress,status) \ magick_threads(image,threshold_image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { double channel_bias[MaxPixelChannels], channel_sum[MaxPixelChannels]; register const Quantum *magick_restrict p, *magick_restrict pixels; register Quantum *magick_restrict q; register ssize_t i, x; ssize_t center, u, v; if (status == MagickFalse) continue; p=GetCacheViewVirtualPixels(image_view,-((ssize_t) width/2L),y-(ssize_t) (height/2L),image->columns+width,height,exception); q=QueueCacheViewAuthenticPixels(threshold_view,0,y,threshold_image->columns, 1,exception); if ((p == (const Quantum *) NULL) || (q == (Quantum *) NULL)) { status=MagickFalse; continue; } center=(ssize_t) GetPixelChannels(image)*(image->columns+width)*(height/2L)+ GetPixelChannels(image)*(width/2); for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); PixelTrait threshold_traits=GetPixelChannelTraits(threshold_image, channel); if ((traits == UndefinedPixelTrait) || (threshold_traits == UndefinedPixelTrait)) continue; if (((threshold_traits & CopyPixelTrait) != 0) || (GetPixelWriteMask(image,p) == 0)) { SetPixelChannel(threshold_image,channel,p[center+i],q); continue; } pixels=p; channel_bias[channel]=0.0; channel_sum[channel]=0.0; for (v=0; v < (ssize_t) height; v++) { for (u=0; u < (ssize_t) width; u++) { if (u == (ssize_t) (width-1)) channel_bias[channel]+=pixels[i]; channel_sum[channel]+=pixels[i]; pixels+=GetPixelChannels(image); } pixels+=GetPixelChannels(image)*image->columns; } } for (x=0; x < (ssize_t) image->columns; x++) { for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { double mean; PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); PixelTrait threshold_traits=GetPixelChannelTraits(threshold_image, channel); if ((traits == UndefinedPixelTrait) || (threshold_traits == UndefinedPixelTrait)) continue; if (((threshold_traits & CopyPixelTrait) != 0) || (GetPixelWriteMask(image,p) == 0)) { SetPixelChannel(threshold_image,channel,p[center+i],q); continue; } channel_sum[channel]-=channel_bias[channel]; channel_bias[channel]=0.0; pixels=p; for (v=0; v < (ssize_t) height; v++) { channel_bias[channel]+=pixels[i]; pixels+=(width-1)*GetPixelChannels(image); channel_sum[channel]+=pixels[i]; pixels+=GetPixelChannels(image)*(image->columns+1); } mean=(double) (channel_sum[channel]/number_pixels+bias); SetPixelChannel(threshold_image,channel,(Quantum) ((double) p[center+i] <= mean ? 0 : QuantumRange),q); } p+=GetPixelChannels(image); q+=GetPixelChannels(threshold_image); } if (SyncCacheViewAuthenticPixels(threshold_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp critical (MagickCore_AdaptiveThresholdImage) #endif proceed=SetImageProgress(image,AdaptiveThresholdImageTag,progress++, image->rows); if (proceed == MagickFalse) status=MagickFalse; } } threshold_image->type=image->type; threshold_view=DestroyCacheView(threshold_view); image_view=DestroyCacheView(image_view); if (status == MagickFalse) threshold_image=DestroyImage(threshold_image); return(threshold_image); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % A u t o T h r e s o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % AutoThresholdImage() automatically selects a threshold and replaces each % pixel in the image with a black pixel if the image intentsity is less than % the selected threshold otherwise white. % % 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; register 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=(ssize_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; register 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=0; 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, ExceptionInfo *exception) { double a, b, c, count, distance, inverse_ratio, max_distance, segment, x1, x2, y1, y2; register 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; register 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) ResetMagickMemory(histogram,0,(MaxIntensity+1UL)*sizeof(*histogram)); image_view=AcquireVirtualCacheView(image,exception); for (y=0; y < (ssize_t) image->rows; y++) { register const Quantum *magick_restrict p; register 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(image,histogram,exception); 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); 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,4) shared(progress,status) \ magick_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register ssize_t x; register Quantum *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (Quantum *) NULL) { status=MagickFalse; continue; } for (x=0; x < (ssize_t) image->columns; x++) { double pixel; register ssize_t i; if (GetPixelWriteMask(image,q) == 0) { q+=GetPixelChannels(image); continue; } pixel=GetPixelIntensity(image,q); for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); if ((traits & UpdatePixelTrait) == 0) continue; if (image->channel_mask != DefaultChannels) pixel=(double) q[i]; q[i]=(Quantum) (pixel <= threshold ? 0 : QuantumRange); } q+=GetPixelChannels(image); } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp critical (MagickCore_BilevelImage) #endif proceed=SetImageProgress(image,ThresholdImageTag,progress++, image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % B l a c k T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % BlackThresholdImage() is like ThresholdImage() but forces all pixels below % the threshold into black while leaving all pixels at or above the threshold % unchanged. % % The format of the BlackThresholdImage method is: % % MagickBooleanType BlackThresholdImage(Image *image, % const char *threshold,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o threshold: define the threshold value. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType BlackThresholdImage(Image *image, const char *thresholds,ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" CacheView *image_view; GeometryInfo geometry_info; MagickBooleanType status; MagickOffsetType progress; PixelInfo threshold; MagickStatusType flags; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (thresholds == (const char *) NULL) return(MagickTrue); if (SetImageStorageClass(image,DirectClass,exception) == MagickFalse) return(MagickFalse); if (IsGrayColorspace(image->colorspace) != MagickFalse) (void) SetImageColorspace(image,sRGBColorspace,exception); GetPixelInfo(image,&threshold); flags=ParseGeometry(thresholds,&geometry_info); threshold.red=geometry_info.rho; threshold.green=geometry_info.rho; threshold.blue=geometry_info.rho; threshold.black=geometry_info.rho; threshold.alpha=100.0; if ((flags & SigmaValue) != 0) threshold.green=geometry_info.sigma; if ((flags & XiValue) != 0) threshold.blue=geometry_info.xi; if ((flags & PsiValue) != 0) threshold.alpha=geometry_info.psi; if (threshold.colorspace == CMYKColorspace) { if ((flags & PsiValue) != 0) threshold.black=geometry_info.psi; if ((flags & ChiValue) != 0) threshold.alpha=geometry_info.chi; } if ((flags & PercentValue) != 0) { threshold.red*=(MagickRealType) (QuantumRange/100.0); threshold.green*=(MagickRealType) (QuantumRange/100.0); threshold.blue*=(MagickRealType) (QuantumRange/100.0); threshold.black*=(MagickRealType) (QuantumRange/100.0); threshold.alpha*=(MagickRealType) (QuantumRange/100.0); } /* White threshold image. */ status=MagickTrue; progress=0; image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static,4) shared(progress,status) \ magick_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register ssize_t x; register Quantum *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (Quantum *) NULL) { status=MagickFalse; continue; } for (x=0; x < (ssize_t) image->columns; x++) { double pixel; register ssize_t i; if (GetPixelWriteMask(image,q) == 0) { q+=GetPixelChannels(image); continue; } pixel=GetPixelIntensity(image,q); for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); if ((traits & UpdatePixelTrait) == 0) continue; if (image->channel_mask != DefaultChannels) pixel=(double) q[i]; if (pixel < GetPixelInfoChannel(&threshold,channel)) q[i]=(Quantum) 0; } q+=GetPixelChannels(image); } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp critical (MagickCore_BlackThresholdImage) #endif proceed=SetImageProgress(image,ThresholdImageTag,progress++, image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % C l a m p I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % ClampImage() set each pixel whose value is below zero to zero and any the % pixel whose value is above the quantum range to the quantum range (e.g. % 65535) otherwise the pixel value remains unchanged. % % The format of the ClampImage method is: % % MagickBooleanType ClampImage(Image *image,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType ClampImage(Image *image,ExceptionInfo *exception) { #define ClampImageTag "Clamp/Image" CacheView *image_view; MagickBooleanType status; MagickOffsetType progress; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (image->storage_class == PseudoClass) { register ssize_t i; register PixelInfo *magick_restrict q; q=image->colormap; for (i=0; i < (ssize_t) image->colors; i++) { q->red=(double) ClampPixel(q->red); q->green=(double) ClampPixel(q->green); q->blue=(double) ClampPixel(q->blue); q->alpha=(double) ClampPixel(q->alpha); q++; } return(SyncImage(image,exception)); } /* Clamp image. */ status=MagickTrue; progress=0; image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static,4) shared(progress,status) \ magick_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register ssize_t x; register Quantum *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (Quantum *) NULL) { status=MagickFalse; continue; } for (x=0; x < (ssize_t) image->columns; x++) { register ssize_t i; if (GetPixelWriteMask(image,q) == 0) { q+=GetPixelChannels(image); continue; } for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); if ((traits & UpdatePixelTrait) == 0) continue; q[i]=ClampPixel((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 critical (MagickCore_ClampImage) #endif proceed=SetImageProgress(image,ClampImageTag,progress++,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % D e s t r o y T h r e s h o l d M a p % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % DestroyThresholdMap() de-allocate the given ThresholdMap % % The format of the ListThresholdMaps method is: % % ThresholdMap *DestroyThresholdMap(Threshold *map) % % A description of each parameter follows. % % o map: Pointer to the Threshold map to destroy % */ MagickExport ThresholdMap *DestroyThresholdMap(ThresholdMap *map) { assert(map != (ThresholdMap *) NULL); if (map->map_id != (char *) NULL) map->map_id=DestroyString(map->map_id); if (map->description != (char *) NULL) map->description=DestroyString(map->description); if (map->levels != (ssize_t *) NULL) map->levels=(ssize_t *) RelinquishMagickMemory(map->levels); map=(ThresholdMap *) RelinquishMagickMemory(map); return(map); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % G e t T h r e s h o l d M a p % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % GetThresholdMap() loads and searches one or more threshold map files for the % map matching the given name or alias. % % The format of the GetThresholdMap method is: % % ThresholdMap *GetThresholdMap(const char *map_id, % ExceptionInfo *exception) % % A description of each parameter follows. % % o map_id: ID of the map to look for. % % o exception: return any errors or warnings in this structure. % */ MagickExport ThresholdMap *GetThresholdMap(const char *map_id, ExceptionInfo *exception) { ThresholdMap *map; map=GetThresholdMapFile(MinimalThresholdMap,"built-in",map_id,exception); if (map != (ThresholdMap *) NULL) return(map); #if !defined(MAGICKCORE_ZERO_CONFIGURATION_SUPPORT) { const StringInfo *option; LinkedListInfo *options; options=GetConfigureOptions(ThresholdsFilename,exception); option=(const StringInfo *) GetNextValueInLinkedList(options); while (option != (const StringInfo *) NULL) { map=GetThresholdMapFile((const char *) GetStringInfoDatum(option), GetStringInfoPath(option),map_id,exception); if (map != (ThresholdMap *) NULL) break; option=(const StringInfo *) GetNextValueInLinkedList(options); } options=DestroyConfigureOptions(options); } #endif return(map); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % + G e t T h r e s h o l d M a p F i l e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % GetThresholdMapFile() look for a given threshold map name or alias in the % given XML file data, and return the allocated the map when found. % % The format of the ListThresholdMaps method is: % % ThresholdMap *GetThresholdMap(const char *xml,const char *filename, % const char *map_id,ExceptionInfo *exception) % % A description of each parameter follows. % % o xml: The threshold map list in XML format. % % o filename: The threshold map XML filename. % % o map_id: ID of the map to look for in XML list. % % o exception: return any errors or warnings in this structure. % */ static ThresholdMap *GetThresholdMapFile(const char *xml,const char *filename, const char *map_id,ExceptionInfo *exception) { char *p; const char *attribute, *content; double value; register ssize_t i; ThresholdMap *map; XMLTreeInfo *description, *levels, *threshold, *thresholds; (void) LogMagickEvent(ConfigureEvent,GetMagickModule(), "Loading threshold map file \"%s\" ...",filename); map=(ThresholdMap *) NULL; thresholds=NewXMLTree(xml,exception); if (thresholds == (XMLTreeInfo *) NULL) return(map); for (threshold=GetXMLTreeChild(thresholds,"threshold"); threshold != (XMLTreeInfo *) NULL; threshold=GetNextXMLTreeTag(threshold)) { attribute=GetXMLTreeAttribute(threshold,"map"); if ((attribute != (char *) NULL) && (LocaleCompare(map_id,attribute) == 0)) break; attribute=GetXMLTreeAttribute(threshold,"alias"); if ((attribute != (char *) NULL) && (LocaleCompare(map_id,attribute) == 0)) break; } if (threshold == (XMLTreeInfo *) NULL) { thresholds=DestroyXMLTree(thresholds); return(map); } description=GetXMLTreeChild(threshold,"description"); if (description == (XMLTreeInfo *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingElement", ", map \"%s\"",map_id); thresholds=DestroyXMLTree(thresholds); return(map); } levels=GetXMLTreeChild(threshold,"levels"); if (levels == (XMLTreeInfo *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingElement", ", map \"%s\"", map_id); thresholds=DestroyXMLTree(thresholds); return(map); } map=(ThresholdMap *) AcquireMagickMemory(sizeof(ThresholdMap)); if (map == (ThresholdMap *) NULL) ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireThresholdMap"); map->map_id=(char *) NULL; map->description=(char *) NULL; map->levels=(ssize_t *) NULL; attribute=GetXMLTreeAttribute(threshold,"map"); if (attribute != (char *) NULL) map->map_id=ConstantString(attribute); content=GetXMLTreeContent(description); if (content != (char *) NULL) map->description=ConstantString(content); attribute=GetXMLTreeAttribute(levels,"width"); if (attribute == (char *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingAttribute", ", 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", ", 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", ", 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", ", 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", ", 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", ", 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", ", 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", " 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", " %.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", " 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", ""); thresholds=DestroyXMLTree(thresholds); return(MagickFalse); } alias=GetXMLTreeAttribute(threshold,"alias"); description=GetXMLTreeChild(threshold,"description"); if (description == (XMLTreeInfo *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingElement", ", map \"%s\"",map); thresholds=DestroyXMLTree(thresholds); return(MagickFalse); } content=GetXMLTreeContent(description); if (content == (char *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingContent", ", map \"%s\"", map); thresholds=DestroyXMLTree(thresholds); return(MagickFalse); } (void) FormatLocaleFile(file,"%-16s %-12s %s\n",map,alias ? alias : "", content); } thresholds=DestroyXMLTree(thresholds); return(MagickTrue); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % L i s t T h r e s h o l d M a p s % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % ListThresholdMaps() lists the threshold maps and their descriptions % as defined by "threshold.xml" to a file. % % The format of the ListThresholdMaps method is: % % MagickBooleanType ListThresholdMaps(FILE *file,ExceptionInfo *exception) % % A description of each parameter follows. % % o file: An pointer to the output FILE. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType ListThresholdMaps(FILE *file, ExceptionInfo *exception) { const StringInfo *option; LinkedListInfo *options; MagickStatusType status; status=MagickTrue; if (file == (FILE *) NULL) file=stdout; options=GetConfigureOptions(ThresholdsFilename,exception); (void) FormatLocaleFile(file, "\n Threshold Maps for Ordered Dither Operations\n"); option=(const StringInfo *) GetNextValueInLinkedList(options); while (option != (const StringInfo *) NULL) { (void) FormatLocaleFile(file,"\nPath: %s\n\n",GetStringInfoPath(option)); status&=ListThresholdMapFile(file,(const char *) GetStringInfoDatum(option), GetStringInfoPath(option),exception); option=(const StringInfo *) GetNextValueInLinkedList(options); } options=DestroyConfigureOptions(options); return(status != 0 ? MagickTrue : MagickFalse); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % O r d e r e d D i t h e r I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % OrderedDitherImage() will perform a ordered dither based on a number % of pre-defined dithering threshold maps, but over multiple intensity % levels, which can be different for different channels, according to the % input argument. % % The format of the OrderedDitherImage method is: % % MagickBooleanType OrderedDitherImage(Image *image, % const char *threshold_map,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o threshold_map: A string containing the name of the threshold dither % map to use, followed by zero or more numbers representing the number % of color levels tho dither between. % % Any level number less than 2 will be equivalent to 2, and means only % binary dithering will be applied to each color channel. % % No numbers also means a 2 level (bitmap) dither will be applied to all % channels, while a single number is the number of levels applied to each % channel in sequence. More numbers will be applied in turn to each of % the color channels. % % For example: "o3x3,6" will generate a 6 level posterization of the % image with a ordered 3x3 diffused pixel dither being applied between % each level. While checker,8,8,4 will produce a 332 colormaped image % with only a single checkerboard hash pattern (50% grey) between each % color level, to basically double the number of color levels with % a bare minimim of dithering. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType OrderedDitherImage(Image *image, const char *threshold_map,ExceptionInfo *exception) { #define DitherImageTag "Dither/Image" CacheView *image_view; char token[MagickPathExtent]; const char *p; double levels[CompositePixelChannel]; MagickBooleanType status; MagickOffsetType progress; register ssize_t i; ssize_t y; ThresholdMap *map; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickCoreSignature); if (threshold_map == (const char *) NULL) return(MagickTrue); p=(char *) threshold_map; while (((isspace((int) ((unsigned char) *p)) != 0) || (*p == ',')) && (*p != '\0')) p++; threshold_map=p; while (((isspace((int) ((unsigned char) *p)) == 0) && (*p != ',')) && (*p != '\0')) { if ((p-threshold_map) >= (MagickPathExtent-1)) break; token[p-threshold_map]=(*p); p++; } token[p-threshold_map]='\0'; map=GetThresholdMap(token,exception); if (map == (ThresholdMap *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "InvalidArgument","%s : '%s'","ordered-dither",threshold_map); return(MagickFalse); } for (i=0; i < MaxPixelChannels; i++) levels[i]=2.0; p=strchr((char *) threshold_map,','); if ((p != (char *) NULL) && (isdigit((int) ((unsigned char) *(++p))) != 0)) { 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++) { GetNextToken(p,&p,MagickPathExtent,token); if (*token == ',') GetNextToken(p,&p,MagickPathExtent,token); levels[i]=StringToDouble(token,(char **) NULL); } } for (i=0; i < MaxPixelChannels; i++) if (fabs(levels[i]) >= 1) levels[i]-=1.0; if (SetImageStorageClass(image,DirectClass,exception) == MagickFalse) return(MagickFalse); status=MagickTrue; progress=0; image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static,4) shared(progress,status) \ magick_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register ssize_t x; register Quantum *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (Quantum *) NULL) { status=MagickFalse; continue; } for (x=0; x < (ssize_t) image->columns; x++) { register ssize_t i; ssize_t n; n=0; if (GetPixelWriteMask(image,q) == 0) { q+=GetPixelChannels(image); continue; } for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { ssize_t level, threshold; PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); if ((traits & UpdatePixelTrait) == 0) continue; if (fabs(levels[n]) < MagickEpsilon) { 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 critical (MagickCore_OrderedDitherImage) #endif proceed=SetImageProgress(image,DitherImageTag,progress++,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); map=DestroyThresholdMap(map); return(MagickTrue); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % P e r c e p t i b l e I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % PerceptibleImage() set each pixel whose value is less than |epsilon| to % epsilon or -epsilon (whichever is closer) otherwise the pixel value remains % unchanged. % % The format of the PerceptibleImage method is: % % MagickBooleanType PerceptibleImage(Image *image,const double epsilon, % ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o epsilon: the epsilon threshold (e.g. 1.0e-9). % % o exception: return any errors or warnings in this structure. % */ static inline Quantum PerceptibleThreshold(const Quantum quantum, const double epsilon) { double sign; sign=(double) quantum < 0.0 ? -1.0 : 1.0; if ((sign*quantum) >= epsilon) return(quantum); return((Quantum) (sign*epsilon)); } MagickExport MagickBooleanType PerceptibleImage(Image *image, const double epsilon,ExceptionInfo *exception) { #define PerceptibleImageTag "Perceptible/Image" CacheView *image_view; MagickBooleanType status; MagickOffsetType progress; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (image->storage_class == PseudoClass) { register ssize_t i; register PixelInfo *magick_restrict q; q=image->colormap; for (i=0; i < (ssize_t) image->colors; i++) { q->red=(double) PerceptibleThreshold(ClampToQuantum(q->red), epsilon); q->green=(double) PerceptibleThreshold(ClampToQuantum(q->green), epsilon); q->blue=(double) PerceptibleThreshold(ClampToQuantum(q->blue), epsilon); q->alpha=(double) PerceptibleThreshold(ClampToQuantum(q->alpha), epsilon); q++; } return(SyncImage(image,exception)); } /* Perceptible image. */ status=MagickTrue; progress=0; image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static,4) shared(progress,status) \ magick_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register ssize_t x; register Quantum *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (Quantum *) NULL) { status=MagickFalse; continue; } for (x=0; x < (ssize_t) image->columns; x++) { register ssize_t i; if (GetPixelWriteMask(image,q) == 0) { q+=GetPixelChannels(image); continue; } for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); if (traits == UndefinedPixelTrait) continue; q[i]=PerceptibleThreshold(q[i],epsilon); } q+=GetPixelChannels(image); } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp critical (MagickCore_PerceptibleImage) #endif proceed=SetImageProgress(image,PerceptibleImageTag,progress++,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % R a n d o m T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % RandomThresholdImage() changes the value of individual pixels based on the % intensity of each pixel compared to a random threshold. The result is a % low-contrast, two color image. % % The format of the RandomThresholdImage method is: % % MagickBooleanType RandomThresholdImage(Image *image, % const char *thresholds,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o low,high: Specify the high and low thresholds. These values range from % 0 to QuantumRange. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType RandomThresholdImage(Image *image, const double min_threshold, const double max_threshold,ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" CacheView *image_view; MagickBooleanType status; MagickOffsetType progress; PixelInfo threshold; RandomInfo **magick_restrict random_info; ssize_t y; #if defined(MAGICKCORE_OPENMP_SUPPORT) unsigned long key; #endif assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickCoreSignature); if (SetImageStorageClass(image,DirectClass,exception) == MagickFalse) return(MagickFalse); GetPixelInfo(image,&threshold); /* Random threshold image. */ status=MagickTrue; progress=0; random_info=AcquireRandomInfoThreadSet(); image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) key=GetRandomSecretKey(random_info[0]); #pragma omp parallel for schedule(static,4) shared(progress,status) \ magick_threads(image,image,image->rows,key == ~0UL) #endif for (y=0; y < (ssize_t) image->rows; y++) { const int id = GetOpenMPThreadId(); register Quantum *magick_restrict q; register ssize_t x; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (Quantum *) NULL) { status=MagickFalse; continue; } for (x=0; x < (ssize_t) image->columns; x++) { register ssize_t i; if (GetPixelWriteMask(image,q) == 0) { q+=GetPixelChannels(image); continue; } for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { double threshold; PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); if ((traits & UpdatePixelTrait) == 0) continue; if ((double) q[i] < min_threshold) threshold=min_threshold; else if ((double) q[i] > max_threshold) threshold=max_threshold; else threshold=(double) (QuantumRange* GetPseudoRandomValue(random_info[id])); q[i]=(double) q[i] <= threshold ? 0 : QuantumRange; } q+=GetPixelChannels(image); } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp critical (MagickCore_RandomThresholdImage) #endif proceed=SetImageProgress(image,ThresholdImageTag,progress++, image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); random_info=DestroyRandomInfoThreadSet(random_info); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % W h i t e T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % WhiteThresholdImage() is like ThresholdImage() but forces all pixels above % the threshold into white while leaving all pixels at or below the threshold % unchanged. % % The format of the WhiteThresholdImage method is: % % MagickBooleanType WhiteThresholdImage(Image *image, % const char *threshold,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o threshold: Define the threshold value. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType WhiteThresholdImage(Image *image, const char *thresholds,ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" CacheView *image_view; GeometryInfo geometry_info; MagickBooleanType status; MagickOffsetType progress; PixelInfo threshold; MagickStatusType flags; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (thresholds == (const char *) NULL) return(MagickTrue); if (SetImageStorageClass(image,DirectClass,exception) == MagickFalse) return(MagickFalse); if (IsGrayColorspace(image->colorspace) != MagickFalse) (void) TransformImageColorspace(image,sRGBColorspace,exception); GetPixelInfo(image,&threshold); flags=ParseGeometry(thresholds,&geometry_info); threshold.red=geometry_info.rho; threshold.green=geometry_info.rho; threshold.blue=geometry_info.rho; threshold.black=geometry_info.rho; threshold.alpha=100.0; if ((flags & SigmaValue) != 0) threshold.green=geometry_info.sigma; if ((flags & XiValue) != 0) threshold.blue=geometry_info.xi; if ((flags & PsiValue) != 0) threshold.alpha=geometry_info.psi; if (threshold.colorspace == CMYKColorspace) { if ((flags & PsiValue) != 0) threshold.black=geometry_info.psi; if ((flags & ChiValue) != 0) threshold.alpha=geometry_info.chi; } if ((flags & PercentValue) != 0) { threshold.red*=(MagickRealType) (QuantumRange/100.0); threshold.green*=(MagickRealType) (QuantumRange/100.0); threshold.blue*=(MagickRealType) (QuantumRange/100.0); threshold.black*=(MagickRealType) (QuantumRange/100.0); threshold.alpha*=(MagickRealType) (QuantumRange/100.0); } /* White threshold image. */ status=MagickTrue; progress=0; image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static,4) shared(progress,status) \ magick_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register ssize_t x; register Quantum *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (Quantum *) NULL) { status=MagickFalse; continue; } for (x=0; x < (ssize_t) image->columns; x++) { double pixel; register ssize_t i; if (GetPixelWriteMask(image,q) == 0) { q+=GetPixelChannels(image); continue; } pixel=GetPixelIntensity(image,q); for (i=0; i < (ssize_t) GetPixelChannels(image); i++) { PixelChannel channel=GetPixelChannelChannel(image,i); PixelTrait traits=GetPixelChannelTraits(image,channel); if ((traits & UpdatePixelTrait) == 0) continue; if (image->channel_mask != DefaultChannels) pixel=(double) q[i]; if (pixel > GetPixelInfoChannel(&threshold,channel)) q[i]=QuantumRange; } q+=GetPixelChannels(image); } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp critical (MagickCore_WhiteThresholdImage) #endif proceed=SetImageProgress(image,ThresholdImageTag,progress++, image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); }