/* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % 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 1999-2019 ImageMagick Studio LLC, a non-profit organization % % dedicated to making software imaging solutions freely available. % % % % You may not use this file except in compliance with the License. You may % % obtain a copy of the License at % % % % https://imagemagick.org/script/license.php % % % % Unless required by applicable law or agreed to in writing, software % % distributed under the License is distributed on an "AS IS" BASIS, % % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. % % See the License for the specific language governing permissions and % % limitations under the License. % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % */ /* Include declarations. */ #include "magick/studio.h" #include "magick/property.h" #include "magick/blob.h" #include "magick/cache-view.h" #include "magick/color.h" #include "magick/color-private.h" #include "magick/colormap.h" #include "magick/colorspace.h" #include "magick/colorspace-private.h" #include "magick/configure.h" #include "magick/constitute.h" #include "magick/decorate.h" #include "magick/draw.h" #include "magick/enhance.h" #include "magick/exception.h" #include "magick/exception-private.h" #include "magick/effect.h" #include "magick/fx.h" #include "magick/gem.h" #include "magick/geometry.h" #include "magick/image-private.h" #include "magick/list.h" #include "magick/log.h" #include "magick/memory_.h" #include "magick/monitor.h" #include "magick/monitor-private.h" #include "magick/montage.h" #include "magick/option.h" #include "magick/pixel-private.h" #include "magick/quantize.h" #include "magick/quantum.h" #include "magick/random_.h" #include "magick/random-private.h" #include "magick/resize.h" #include "magick/resource_.h" #include "magick/segment.h" #include "magick/shear.h" #include "magick/signature-private.h" #include "magick/string_.h" #include "magick/string-private.h" #include "magick/thread-private.h" #include "magick/threshold.h" #include "magick/transform.h" #include "magick/xml-tree.h" /* Define declarations. */ #define ThresholdsFilename "thresholds.xml" /* Typedef declarations. */ struct _ThresholdMap { char *map_id, *description; size_t width, height; ssize_t divisor, *levels; }; /* Static declarations. */ static const char *MinimalThresholdMap = "" "" " " " Threshold 1x1 (non-dither)" " " " 1" " " " " " " " Checkerboard 2x1 (dither)" " " " 1 2" " 2 1" " " " " ""; /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % A d a p t i v e T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % AdaptiveThresholdImage() selects an individual threshold for each pixel % based on the range of intensity values in its local neighborhood. This % allows for thresholding of an image whose global intensity histogram % doesn't contain distinctive peaks. % % The format of the AdaptiveThresholdImage method is: % % Image *AdaptiveThresholdImage(const Image *image, % const size_t width,const size_t height, % const ssize_t offset,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o width: the width of the local neighborhood. % % o height: the height of the local neighborhood. % % o offset: the mean offset. % % o exception: return any errors or warnings in this structure. % */ MagickExport Image *AdaptiveThresholdImage(const Image *image, const size_t width,const size_t height,const ssize_t offset, ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" CacheView *image_view, *threshold_view; Image *threshold_image; MagickBooleanType status; MagickOffsetType progress; MagickPixelPacket zero; MagickRealType number_pixels; ssize_t y; assert(image != (const Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickCoreSignature); threshold_image=CloneImage(image,0,0,MagickTrue,exception); if (threshold_image == (Image *) NULL) return((Image *) NULL); if (width == 0) return(threshold_image); if (SetImageStorageClass(threshold_image,DirectClass) == MagickFalse) { InheritException(exception,&threshold_image->exception); threshold_image=DestroyImage(threshold_image); return((Image *) NULL); } /* Local adaptive threshold. */ status=MagickTrue; progress=0; GetMagickPixelPacket(image,&zero); number_pixels=(MagickRealType) (width*height); image_view=AcquireVirtualCacheView(image,exception); threshold_view=AcquireAuthenticCacheView(threshold_image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,threshold_image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { MagickBooleanType sync; MagickPixelPacket channel_bias, channel_sum; register const IndexPacket *magick_restrict indexes; register const PixelPacket *magick_restrict p, *magick_restrict r; register IndexPacket *magick_restrict threshold_indexes; register PixelPacket *magick_restrict q; register ssize_t x; ssize_t u, v; if (status == MagickFalse) continue; p=GetCacheViewVirtualPixels(image_view,-((ssize_t) width/2L),y-(ssize_t) height/2L,image->columns+width,height,exception); q=GetCacheViewAuthenticPixels(threshold_view,0,y,threshold_image->columns,1, exception); if ((p == (const PixelPacket *) NULL) || (q == (PixelPacket *) NULL)) { status=MagickFalse; continue; } indexes=GetCacheViewVirtualIndexQueue(image_view); threshold_indexes=GetCacheViewAuthenticIndexQueue(threshold_view); channel_bias=zero; channel_sum=zero; r=p; for (v=0; v < (ssize_t) height; v++) { for (u=0; u < (ssize_t) width; u++) { if (u == (ssize_t) (width-1)) { channel_bias.red+=r[u].red; channel_bias.green+=r[u].green; channel_bias.blue+=r[u].blue; channel_bias.opacity+=r[u].opacity; if (image->colorspace == CMYKColorspace) channel_bias.index=(MagickRealType) GetPixelIndex(indexes+(r-p)+u); } channel_sum.red+=r[u].red; channel_sum.green+=r[u].green; channel_sum.blue+=r[u].blue; channel_sum.opacity+=r[u].opacity; if (image->colorspace == CMYKColorspace) channel_sum.index=(MagickRealType) GetPixelIndex(indexes+(r-p)+u); } r+=image->columns+width; } for (x=0; x < (ssize_t) image->columns; x++) { MagickPixelPacket mean; mean=zero; r=p; channel_sum.red-=channel_bias.red; channel_sum.green-=channel_bias.green; channel_sum.blue-=channel_bias.blue; channel_sum.opacity-=channel_bias.opacity; channel_sum.index-=channel_bias.index; channel_bias=zero; for (v=0; v < (ssize_t) height; v++) { channel_bias.red+=r[0].red; channel_bias.green+=r[0].green; channel_bias.blue+=r[0].blue; channel_bias.opacity+=r[0].opacity; if (image->colorspace == CMYKColorspace) channel_bias.index=(MagickRealType) GetPixelIndex(indexes+x+(r-p)+0); channel_sum.red+=r[width-1].red; channel_sum.green+=r[width-1].green; channel_sum.blue+=r[width-1].blue; channel_sum.opacity+=r[width-1].opacity; if (image->colorspace == CMYKColorspace) channel_sum.index=(MagickRealType) GetPixelIndex(indexes+x+(r-p)+ width-1); r+=image->columns+width; } mean.red=(MagickRealType) (channel_sum.red/number_pixels+offset); mean.green=(MagickRealType) (channel_sum.green/number_pixels+offset); mean.blue=(MagickRealType) (channel_sum.blue/number_pixels+offset); mean.opacity=(MagickRealType) (channel_sum.opacity/number_pixels+offset); if (image->colorspace == CMYKColorspace) mean.index=(MagickRealType) (channel_sum.index/number_pixels+offset); SetPixelRed(q,((MagickRealType) GetPixelRed(q) <= mean.red) ? 0 : QuantumRange); SetPixelGreen(q,((MagickRealType) GetPixelGreen(q) <= mean.green) ? 0 : QuantumRange); SetPixelBlue(q,((MagickRealType) GetPixelBlue(q) <= mean.blue) ? 0 : QuantumRange); SetPixelOpacity(q,((MagickRealType) GetPixelOpacity(q) <= mean.opacity) ? 0 : QuantumRange); if (image->colorspace == CMYKColorspace) SetPixelIndex(threshold_indexes+x,(((MagickRealType) GetPixelIndex( threshold_indexes+x) <= mean.index) ? 0 : QuantumRange)); p++; q++; } sync=SyncCacheViewAuthenticPixels(threshold_view,exception); if (sync == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,ThresholdImageTag,progress,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } threshold_view=DestroyCacheView(threshold_view); image_view=DestroyCacheView(image_view); if (status == MagickFalse) threshold_image=DestroyImage(threshold_image); return(threshold_image); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % A u t o T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % AutoThresholdImage() automatically performs image thresholding % dependent on which method you specify. % % The format of the AutoThresholdImage method is: % % MagickBooleanType AutoThresholdImage(Image *image, % const AutoThresholdMethod method,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: The image to auto-threshold. % % o method: choose from Kapur, OTSU, or Triangle. % % o exception: return any errors or warnings in this structure. % */ static double KapurThreshold(const Image *image,const double *histogram, ExceptionInfo *exception) { #define MaxIntensity 255 double *black_entropy, *cumulative_histogram, entropy, epsilon, maximum_entropy, *white_entropy; 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=(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; 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=1; i <= (ssize_t) MaxIntensity; i++) { omega[i]=omega[i-1]+probability[i]; myu[i]=myu[i-1]+i*probability[i]; } /* Sigma maximization: inter-class variance and compute optimal threshold. */ threshold=0; max_sigma=0.0; for (i=0; i < (ssize_t) MaxIntensity; i++) { sigma[i]=0.0; if ((omega[i] != 0.0) && (omega[i] != 1.0)) sigma[i]=pow(myu[MaxIntensity]*omega[i]-myu[i],2.0)/(omega[i]*(1.0- omega[i])); if (sigma[i] > max_sigma) { max_sigma=sigma[i]; threshold=(double) i; } } /* Free resources. */ myu=(double *) RelinquishMagickMemory(myu); omega=(double *) RelinquishMagickMemory(omega); probability=(double *) RelinquishMagickMemory(probability); sigma=(double *) RelinquishMagickMemory(sigma); return(100.0*threshold/MaxIntensity); } static double TriangleThreshold(const Image *image,const double *histogram) { double a, b, c, count, distance, inverse_ratio, max_distance, segment, x1, x2, y1, y2; 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) memset(histogram,0,(MaxIntensity+1UL)*sizeof(*histogram)); image_view=AcquireVirtualCacheView(image,exception); for (y=0; y < (ssize_t) image->rows; y++) { register const PixelPacket *magick_restrict p; register ssize_t x; p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception); if (p == (const PixelPacket *) NULL) break; for (x=0; x < (ssize_t) image->columns; x++) { double intensity = GetPixelIntensity(image,p); histogram[ScaleQuantumToChar(ClampToQuantum(intensity))]++; p++; } } image_view=DestroyCacheView(image_view); /* Normalize histogram. */ sum=0.0; for (i=0; i <= (ssize_t) MaxIntensity; i++) sum+=histogram[i]; gamma=PerceptibleReciprocal(sum); for (i=0; i <= (ssize_t) MaxIntensity; i++) histogram[i]=gamma*histogram[i]; /* Discover threshold from histogram. */ switch (method) { case KapurThresholdMethod: { threshold=KapurThreshold(image,histogram,exception); break; } case OTSUThresholdMethod: default: { threshold=OTSUThreshold(image,histogram,exception); break; } case TriangleThresholdMethod: { threshold=TriangleThreshold(image,histogram); break; } } histogram=(double *) RelinquishMagickMemory(histogram); if (threshold < 0.0) status=MagickFalse; if (status == MagickFalse) return(MagickFalse); /* Threshold image. */ (void) FormatLocaleString(property,MagickPathExtent,"%g%%",threshold); (void) SetImageProperty(image,"auto-threshold:threshold",property); return(BilevelImage(image,QuantumRange*threshold/100.0)); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % B i l e v e l I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % BilevelImage() changes the value of individual pixels based on the % intensity of each pixel channel. The result is a high-contrast image. % % More precisely each channel value of the image is 'thresholded' so that if % it is equal to or less than the given value it is set to zero, while any % value greater than that give is set to it maximum or QuantumRange. % % This function is what is used to implement the "-threshold" operator for % the command line API. % % If the default channel setting is given the image is thresholded using just % the gray 'intensity' of the image, rather than the individual channels. % % The format of the BilevelImageChannel method is: % % MagickBooleanType BilevelImage(Image *image,const double threshold) % MagickBooleanType BilevelImageChannel(Image *image, % const ChannelType channel,const double threshold) % % A description of each parameter follows: % % o image: the image. % % o channel: the channel type. % % o threshold: define the threshold values. % % Aside: You can get the same results as operator using LevelImageChannels() % with the 'threshold' value for both the black_point and the white_point. % */ MagickExport MagickBooleanType BilevelImage(Image *image,const double threshold) { MagickBooleanType status; status=BilevelImageChannel(image,DefaultChannels,threshold); return(status); } MagickExport MagickBooleanType BilevelImageChannel(Image *image, const ChannelType channel,const double threshold) { #define ThresholdImageTag "Threshold/Image" CacheView *image_view; ExceptionInfo *exception; MagickBooleanType status; MagickOffsetType progress; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (SetImageStorageClass(image,DirectClass) == MagickFalse) return(MagickFalse); if (IsGrayColorspace(image->colorspace) != MagickFalse) (void) SetImageColorspace(image,sRGBColorspace); /* Bilevel threshold image. */ status=MagickTrue; progress=0; exception=(&image->exception); image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register IndexPacket *magick_restrict indexes; register ssize_t x; register PixelPacket *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (PixelPacket *) NULL) { status=MagickFalse; continue; } indexes=GetCacheViewAuthenticIndexQueue(image_view); if ((channel & SyncChannels) != 0) { for (x=0; x < (ssize_t) image->columns; x++) { SetPixelRed(q,GetPixelIntensity(image,q) <= threshold ? 0 : QuantumRange); SetPixelGreen(q,GetPixelRed(q)); SetPixelBlue(q,GetPixelRed(q)); q++; } } else for (x=0; x < (ssize_t) image->columns; x++) { if ((channel & RedChannel) != 0) SetPixelRed(q,(MagickRealType) GetPixelRed(q) <= threshold ? 0 : QuantumRange); if ((channel & GreenChannel) != 0) SetPixelGreen(q,(MagickRealType) GetPixelGreen(q) <= threshold ? 0 : QuantumRange); if ((channel & BlueChannel) != 0) SetPixelBlue(q,(MagickRealType) GetPixelBlue(q) <= threshold ? 0 : QuantumRange); if ((channel & OpacityChannel) != 0) { if (image->matte == MagickFalse) SetPixelOpacity(q,(MagickRealType) GetPixelOpacity(q) <= threshold ? 0 : QuantumRange); else SetPixelAlpha(q,(MagickRealType) GetPixelAlpha(q) <= threshold ? OpaqueOpacity : TransparentOpacity); } if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace)) SetPixelIndex(indexes+x,(MagickRealType) GetPixelIndex(indexes+x) <= threshold ? 0 : QuantumRange); q++; } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,ThresholdImageTag,progress,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % B l a c k T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % BlackThresholdImage() is like ThresholdImage() but forces all pixels below % the threshold into black while leaving all pixels at or above the threshold % unchanged. % % The format of the BlackThresholdImage method is: % % MagickBooleanType BlackThresholdImage(Image *image,const char *threshold) % MagickBooleanType BlackThresholdImageChannel(Image *image, % const ChannelType channel,const char *threshold, % ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o channel: the channel or channels to be thresholded. % % o threshold: Define the threshold value. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType BlackThresholdImage(Image *image, const char *threshold) { MagickBooleanType status; status=BlackThresholdImageChannel(image,DefaultChannels,threshold, &image->exception); return(status); } MagickExport MagickBooleanType BlackThresholdImageChannel(Image *image, const ChannelType channel,const char *thresholds,ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" CacheView *image_view; GeometryInfo geometry_info; MagickBooleanType status; MagickOffsetType progress; MagickPixelPacket threshold; MagickStatusType flags; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (thresholds == (const char *) NULL) return(MagickTrue); if (SetImageStorageClass(image,DirectClass) == MagickFalse) return(MagickFalse); GetMagickPixelPacket(image,&threshold); flags=ParseGeometry(thresholds,&geometry_info); threshold.red=geometry_info.rho; threshold.green=geometry_info.sigma; if ((flags & SigmaValue) == 0) threshold.green=threshold.red; threshold.blue=geometry_info.xi; if ((flags & XiValue) == 0) threshold.blue=threshold.red; threshold.opacity=geometry_info.psi; if ((flags & PsiValue) == 0) threshold.opacity=threshold.red; threshold.index=geometry_info.chi; if ((flags & ChiValue) == 0) threshold.index=threshold.red; if ((flags & PercentValue) != 0) { threshold.red*=(MagickRealType) (QuantumRange/100.0); threshold.green*=(MagickRealType) (QuantumRange/100.0); threshold.blue*=(MagickRealType) (QuantumRange/100.0); threshold.opacity*=(MagickRealType) (QuantumRange/100.0); threshold.index*=(MagickRealType) (QuantumRange/100.0); } if ((IsMagickGray(&threshold) == MagickFalse) && (IsGrayColorspace(image->colorspace) != MagickFalse)) (void) SetImageColorspace(image,sRGBColorspace); /* Black threshold image. */ status=MagickTrue; progress=0; image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register IndexPacket *magick_restrict indexes; register ssize_t x; register PixelPacket *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (PixelPacket *) NULL) { status=MagickFalse; continue; } indexes=GetCacheViewAuthenticIndexQueue(image_view); for (x=0; x < (ssize_t) image->columns; x++) { if (((channel & RedChannel) != 0) && ((MagickRealType) GetPixelRed(q) < threshold.red)) SetPixelRed(q,0); if (((channel & GreenChannel) != 0) && ((MagickRealType) GetPixelGreen(q) < threshold.green)) SetPixelGreen(q,0); if (((channel & BlueChannel) != 0) && ((MagickRealType) GetPixelBlue(q) < threshold.blue)) SetPixelBlue(q,0); if (((channel & OpacityChannel) != 0) && ((MagickRealType) GetPixelOpacity(q) < threshold.opacity)) SetPixelOpacity(q,0); if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace) && ((MagickRealType) GetPixelIndex(indexes+x) < threshold.index)) SetPixelIndex(indexes+x,0); q++; } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,ThresholdImageTag,progress,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % C l a m p I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % ClampImage() set each pixel whose value is below zero to zero and any the % pixel whose value is above the quantum range to the quantum range (e.g. % 65535) otherwise the pixel value remains unchanged. % % The format of the ClampImageChannel method is: % % MagickBooleanType ClampImage(Image *image) % MagickBooleanType ClampImageChannel(Image *image, % const ChannelType channel) % % A description of each parameter follows: % % o image: the image. % % o channel: the channel type. % */ MagickExport MagickBooleanType ClampImage(Image *image) { MagickBooleanType status; status=ClampImageChannel(image,DefaultChannels); return(status); } MagickExport MagickBooleanType ClampImageChannel(Image *image, const ChannelType channel) { #define ClampImageTag "Clamp/Image" CacheView *image_view; ExceptionInfo *exception; MagickBooleanType status; MagickOffsetType progress; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (image->storage_class == PseudoClass) { register ssize_t i; register PixelPacket *magick_restrict q; q=image->colormap; for (i=0; i < (ssize_t) image->colors; i++) { SetPixelRed(q,ClampPixel((MagickRealType) GetPixelRed(q))); SetPixelGreen(q,ClampPixel((MagickRealType) GetPixelGreen(q))); SetPixelBlue(q,ClampPixel((MagickRealType) GetPixelBlue(q))); SetPixelOpacity(q,ClampPixel((MagickRealType) GetPixelOpacity(q))); q++; } return(SyncImage(image)); } /* Clamp image. */ status=MagickTrue; progress=0; exception=(&image->exception); image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register IndexPacket *magick_restrict indexes; register ssize_t x; register PixelPacket *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (PixelPacket *) NULL) { status=MagickFalse; continue; } indexes=GetCacheViewAuthenticIndexQueue(image_view); for (x=0; x < (ssize_t) image->columns; x++) { if ((channel & RedChannel) != 0) SetPixelRed(q,ClampPixel((MagickRealType) GetPixelRed(q))); if ((channel & GreenChannel) != 0) SetPixelGreen(q,ClampPixel((MagickRealType) GetPixelGreen(q))); if ((channel & BlueChannel) != 0) SetPixelBlue(q,ClampPixel((MagickRealType) GetPixelBlue(q))); if ((channel & OpacityChannel) != 0) SetPixelOpacity(q,ClampPixel((MagickRealType) GetPixelOpacity(q))); if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace)) SetPixelIndex(indexes+x,ClampPixel((MagickRealType) GetPixelIndex( indexes+x))); q++; } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,ClampImageTag,progress,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % D e s t r o y T h r e s h o l d M a p % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % DestroyThresholdMap() de-allocate the given ThresholdMap % % The format of the ListThresholdMaps method is: % % ThresholdMap *DestroyThresholdMap(Threshold *map) % % A description of each parameter follows. % % o map: Pointer to the Threshold map to destroy % */ MagickExport ThresholdMap *DestroyThresholdMap(ThresholdMap *map) { assert(map != (ThresholdMap *) NULL); if (map->map_id != (char *) NULL) map->map_id=DestroyString(map->map_id); if (map->description != (char *) NULL) map->description=DestroyString(map->description); if (map->levels != (ssize_t *) NULL) map->levels=(ssize_t *) RelinquishMagickMemory(map->levels); map=(ThresholdMap *) RelinquishMagickMemory(map); return(map); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % + G e t T h r e s h o l d M a p F i l e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % GetThresholdMapFile() look for a given threshold map name or alias in the % given XML file data, and return the allocated the map when found. % % The format of the ListThresholdMaps method is: % % ThresholdMap *GetThresholdMap(const char *xml,const char *filename, % const char *map_id,ExceptionInfo *exception) % % A description of each parameter follows. % % o xml: The threshold map list in XML format. % % o filename: The threshold map XML filename. % % o map_id: ID of the map to look for in XML list. % % o exception: return any errors or warnings in this structure. % */ MagickExport ThresholdMap *GetThresholdMapFile(const char *xml, const char *filename,const char *map_id,ExceptionInfo *exception) { const char *attribute, *content; double value; ThresholdMap *map; XMLTreeInfo *description, *levels, *threshold, *thresholds; map = (ThresholdMap *) NULL; (void) LogMagickEvent(ConfigureEvent,GetMagickModule(), "Loading threshold map file \"%s\" ...",filename); thresholds=NewXMLTree(xml,exception); if ( thresholds == (XMLTreeInfo *) NULL ) return(map); for (threshold = GetXMLTreeChild(thresholds,"threshold"); threshold != (XMLTreeInfo *) NULL; threshold = GetNextXMLTreeTag(threshold) ) { attribute=GetXMLTreeAttribute(threshold, "map"); if ((attribute != (char *) NULL) && (LocaleCompare(map_id,attribute) == 0)) break; attribute=GetXMLTreeAttribute(threshold, "alias"); if ((attribute != (char *) NULL) && (LocaleCompare(map_id,attribute) == 0)) break; } if (threshold == (XMLTreeInfo *) NULL) { thresholds=DestroyXMLTree(thresholds); return(map); } description=GetXMLTreeChild(threshold,"description"); if (description == (XMLTreeInfo *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingElement", ", 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); } /* The map has been found -- allocate a Threshold Map to return */ map=(ThresholdMap *) AcquireMagickMemory(sizeof(ThresholdMap)); if (map == (ThresholdMap *) NULL) ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireThresholdMap"); map->map_id=(char *) NULL; map->description=(char *) NULL; map->levels=(ssize_t *) NULL; /* Assign basic attributeibutes. */ attribute=GetXMLTreeAttribute(threshold,"map"); if (attribute != (char *) NULL) map->map_id=ConstantString(attribute); content=GetXMLTreeContent(description); if (content != (char *) NULL) map->description=ConstantString(content); attribute=GetXMLTreeAttribute(levels,"width"); if (attribute == (char *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingAttribute", ", 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); } /* Allocate theshold levels array. */ 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"); { char *p; register ssize_t i; /* Parse levels into integer array. */ for (i=0; i< (ssize_t) (map->width*map->height); i++) { map->levels[i]=(ssize_t) strtol(content,&p,10); if (p == content) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlInvalidContent", " 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); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % G e t T h r e s h o l d M a p % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % GetThresholdMap() load and search one or more threshold map files for the % a map matching the given name or aliase. % % The format of the GetThresholdMap method is: % % ThresholdMap *GetThresholdMap(const char *map_id, % ExceptionInfo *exception) % % A description of each parameter follows. % % o map_id: ID of the map to look for. % % o exception: return any errors or warnings in this structure. % */ MagickExport ThresholdMap *GetThresholdMap(const char *map_id, ExceptionInfo *exception) { const StringInfo *option; LinkedListInfo *options; ThresholdMap *map; map=GetThresholdMapFile(MinimalThresholdMap,"built-in",map_id,exception); if (map != (ThresholdMap *) NULL) return(map); options=GetConfigureOptions(ThresholdsFilename,exception); option=(const StringInfo *) GetNextValueInLinkedList(options); while (option != (const StringInfo *) NULL) { map=GetThresholdMapFile((const char *) GetStringInfoDatum(option), GetStringInfoPath(option),map_id,exception); if (map != (ThresholdMap *) NULL) break; option=(const StringInfo *) GetNextValueInLinkedList(options); } options=DestroyConfigureOptions(options); return(map); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % + L i s t T h r e s h o l d M a p F i l e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % ListThresholdMapFile() lists the threshold maps and their descriptions % in the given XML file data. % % The format of the ListThresholdMaps method is: % % MagickBooleanType ListThresholdMaps(FILE *file,const char*xml, % const char *filename,ExceptionInfo *exception) % % A description of each parameter follows. % % o file: An pointer to the output FILE. % % o xml: The threshold map list in XML format. % % o filename: The threshold map XML filename. % % o exception: return any errors or warnings in this structure. % */ MagickBooleanType ListThresholdMapFile(FILE *file,const char *xml, const char *filename,ExceptionInfo *exception) { XMLTreeInfo *thresholds,*threshold,*description; const char *map,*alias,*content; assert( xml != (char *) NULL ); assert( file != (FILE *) NULL ); (void) LogMagickEvent(ConfigureEvent,GetMagickModule(), "Loading threshold map file \"%s\" ...",filename); thresholds=NewXMLTree(xml,exception); if ( thresholds == (XMLTreeInfo *) NULL ) return(MagickFalse); (void) FormatLocaleFile(file,"%-16s %-12s %s\n","Map","Alias","Description"); (void) FormatLocaleFile(file, "----------------------------------------------------\n"); for( threshold = GetXMLTreeChild(thresholds,"threshold"); threshold != (XMLTreeInfo *) NULL; threshold = GetNextXMLTreeTag(threshold) ) { map = GetXMLTreeAttribute(threshold, "map"); if (map == (char *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingAttribute", ""); thresholds=DestroyXMLTree(thresholds); return(MagickFalse); } alias = GetXMLTreeAttribute(threshold, "alias"); /* alias is optional, no if test needed */ description=GetXMLTreeChild(threshold,"description"); if ( description == (XMLTreeInfo *) NULL ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingElement", ", 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() uses the ordered dithering technique of reducing color % images to monochrome using positional information to retain as much % information as possible. % % WARNING: This function is deprecated, and is now just a call to % the more more powerful OrderedPosterizeImage(); function. % % The format of the OrderedDitherImage method is: % % MagickBooleanType OrderedDitherImage(Image *image) % MagickBooleanType OrderedDitherImageChannel(Image *image, % const ChannelType channel,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o channel: the channel or channels to be thresholded. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType OrderedDitherImage(Image *image) { MagickBooleanType status; status=OrderedDitherImageChannel(image,DefaultChannels,&image->exception); return(status); } MagickExport MagickBooleanType OrderedDitherImageChannel(Image *image, const ChannelType channel,ExceptionInfo *exception) { MagickBooleanType status; /* Call the augumented function OrderedPosterizeImage() */ status=OrderedPosterizeImageChannel(image,channel,"o8x8",exception); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % O r d e r e d P o s t e r i z e I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % OrderedPosterizeImage() will perform a ordered dither based on a number % of pre-defined dithering threshold maps, but over multiple intensity % levels, which can be different for different channels, according to the % input argument. % % The format of the OrderedPosterizeImage method is: % % MagickBooleanType OrderedPosterizeImage(Image *image, % const char *threshold_map,ExceptionInfo *exception) % MagickBooleanType OrderedPosterizeImageChannel(Image *image, % const ChannelType channel,const char *threshold_map, % ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o channel: the channel or channels to be thresholded. % % o threshold_map: A string containing the name of the threshold dither % map to use, followed by zero or more numbers representing the number % of color levels tho dither between. % % Any level number less than 2 will be equivalent to 2, and means only % binary dithering will be applied to each color channel. % % No numbers also means a 2 level (bitmap) dither will be applied to all % channels, while a single number is the number of levels applied to each % channel in sequence. More numbers will be applied in turn to each of % the color channels. % % For example: "o3x3,6" will generate a 6 level posterization of the % image with a ordered 3x3 diffused pixel dither being applied between % each level. While checker,8,8,4 will produce a 332 colormaped image % with only a single checkerboard hash pattern (50% grey) between each % color level, to basically double the number of color levels with % a bare minimim of dithering. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType OrderedPosterizeImage(Image *image, const char *threshold_map,ExceptionInfo *exception) { MagickBooleanType status; status=OrderedPosterizeImageChannel(image,DefaultChannels,threshold_map, exception); return(status); } MagickExport MagickBooleanType OrderedPosterizeImageChannel(Image *image, const ChannelType channel,const char *threshold_map,ExceptionInfo *exception) { #define DitherImageTag "Dither/Image" CacheView *image_view; LongPixelPacket levels; MagickBooleanType status; MagickOffsetType progress; ssize_t y; ThresholdMap *map; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickCoreSignature); if (threshold_map == (const char *) NULL) return(MagickTrue); { char token[MaxTextExtent]; register const char *p; p=(char *)threshold_map; while (((isspace((int) ((unsigned char) *p)) != 0) || (*p == ',')) && (*p != '\0')) p++; threshold_map=p; while (((isspace((int) ((unsigned char) *p)) == 0) && (*p != ',')) && (*p != '\0')) { if ((p-threshold_map) >= (MaxTextExtent-1)) break; token[p-threshold_map] = *p; p++; } token[p-threshold_map] = '\0'; map = GetThresholdMap(token, exception); if ( map == (ThresholdMap *) NULL ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "InvalidArgument","%s : '%s'","ordered-dither",threshold_map); return(MagickFalse); } } /* Set channel levels from extra comma separated arguments Default to 2, the single value given, or individual channel values */ #if 1 { /* parse directly as a comma separated list of integers */ char *p; p = strchr((char *) threshold_map,','); if ( p != (char *) NULL && isdigit((int) ((unsigned char) *(++p))) ) levels.index = (unsigned int) strtoul(p, &p, 10); else levels.index = 2; levels.red = ((channel & RedChannel ) != 0) ? levels.index : 0; levels.green = ((channel & GreenChannel) != 0) ? levels.index : 0; levels.blue = ((channel & BlueChannel) != 0) ? levels.index : 0; levels.opacity = ((channel & OpacityChannel) != 0) ? levels.index : 0; levels.index = ((channel & IndexChannel) != 0 && (image->colorspace == CMYKColorspace)) ? levels.index : 0; /* if more than a single number, each channel has a separate value */ if ( p != (char *) NULL && *p == ',' ) { p=strchr((char *) threshold_map,','); p++; if ((channel & RedChannel) != 0) levels.red = (unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++); if ((channel & GreenChannel) != 0) levels.green = (unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++); if ((channel & BlueChannel) != 0) levels.blue = (unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++); if ((channel & IndexChannel) != 0 && image->colorspace == CMYKColorspace) levels.index=(unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++); if ((channel & OpacityChannel) != 0) levels.opacity = (unsigned int) strtoul(p, &p, 10), (void)(*p == ',' && p++); } } #else /* Parse level values as a geometry */ /* This difficult! * How to map GeometryInfo structure elements into * LongPixelPacket structure elements, but according to channel? * Note the channels list may skip elements!!!! * EG -channel BA -ordered-dither map,2,3 * will need to map g.rho -> l.blue, and g.sigma -> l.opacity * A simpler way is needed, probably converting geometry to a temporary * array, then using channel to advance the index into ssize_t pixel packet. */ #endif #if 0 printf("DEBUG levels r=%u g=%u b=%u a=%u i=%u\n", levels.red, levels.green, levels.blue, levels.opacity, levels.index); #endif { /* Do the posterized ordered dithering of the image */ ssize_t d; /* d = number of psuedo-level divisions added between color levels */ d = map->divisor-1; /* reduce levels to levels - 1 */ levels.red = levels.red ? levels.red-1 : 0; levels.green = levels.green ? levels.green-1 : 0; levels.blue = levels.blue ? levels.blue-1 : 0; levels.opacity = levels.opacity ? levels.opacity-1 : 0; levels.index = levels.index ? levels.index-1 : 0; if (SetImageStorageClass(image,DirectClass) == MagickFalse) { InheritException(exception,&image->exception); return(MagickFalse); } status=MagickTrue; progress=0; image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register IndexPacket *magick_restrict indexes; register ssize_t x; register PixelPacket *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (PixelPacket *) NULL) { status=MagickFalse; continue; } indexes=GetCacheViewAuthenticIndexQueue(image_view); for (x=0; x < (ssize_t) image->columns; x++) { register ssize_t threshold, t, l; /* Figure out the dither threshold for this pixel This must be a integer from 1 to map->divisor-1 */ threshold = map->levels[(x%map->width) +map->width*(y%map->height)]; /* Dither each channel in the image as appropriate Notes on the integer Math... total number of divisions = (levels-1)*(divisor-1)+1) t1 = this colors psuedo_level = q->red * total_divisions / (QuantumRange+1) l = posterization level 0..levels t = dither threshold level 0..divisor-1 NB: 0 only on last Each color_level is of size QuantumRange / (levels-1) NB: All input levels and divisor are already had 1 subtracted Opacity is inverted so 'off' represents transparent. */ if (levels.red) { t = (ssize_t) (QuantumScale*GetPixelRed(q)*(levels.red*d+1)); l = t/d; t = t-l*d; SetPixelRed(q,ClampToQuantum((MagickRealType) ((l+(t >= threshold))*(MagickRealType) QuantumRange/levels.red))); } if (levels.green) { t = (ssize_t) (QuantumScale*GetPixelGreen(q)* (levels.green*d+1)); l = t/d; t = t-l*d; SetPixelGreen(q,ClampToQuantum((MagickRealType) ((l+(t >= threshold))*(MagickRealType) QuantumRange/levels.green))); } if (levels.blue) { t = (ssize_t) (QuantumScale*GetPixelBlue(q)* (levels.blue*d+1)); l = t/d; t = t-l*d; SetPixelBlue(q,ClampToQuantum((MagickRealType) ((l+(t >= threshold))*(MagickRealType) QuantumRange/levels.blue))); } if (levels.opacity) { t = (ssize_t) ((1.0-QuantumScale*GetPixelOpacity(q))* (levels.opacity*d+1)); l = t/d; t = t-l*d; SetPixelOpacity(q,ClampToQuantum((MagickRealType) ((1.0-l-(t >= threshold))*(MagickRealType) QuantumRange/ levels.opacity))); } if (levels.index) { t = (ssize_t) (QuantumScale*GetPixelIndex(indexes+x)* (levels.index*d+1)); l = t/d; t = t-l*d; SetPixelIndex(indexes+x,ClampToQuantum((MagickRealType) ((l+ (t>=threshold))*(MagickRealType) QuantumRange/levels.index))); } q++; } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,DitherImageTag,progress,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); } map=DestroyThresholdMap(map); return(MagickTrue); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % P e r c e p t i b l e I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % PerceptibleImage() set each pixel whose value is less than |epsilon| to % epsilon or -epsilon (whichever is closer) otherwise the pixel value remains % unchanged. % % The format of the PerceptibleImageChannel method is: % % MagickBooleanType PerceptibleImage(Image *image,const double epsilon) % MagickBooleanType PerceptibleImageChannel(Image *image, % const ChannelType channel,const double epsilon) % % A description of each parameter follows: % % o image: the image. % % o channel: the channel type. % % o epsilon: the epsilon threshold (e.g. 1.0e-9). % */ static inline Quantum PerceptibleThreshold(const Quantum quantum, const double epsilon) { double sign; sign=(double) quantum < 0.0 ? -1.0 : 1.0; if ((sign*quantum) >= epsilon) return(quantum); return((Quantum) (sign*epsilon)); } MagickExport MagickBooleanType PerceptibleImage(Image *image, const double epsilon) { MagickBooleanType status; status=PerceptibleImageChannel(image,DefaultChannels,epsilon); return(status); } MagickExport MagickBooleanType PerceptibleImageChannel(Image *image, const ChannelType channel,const double epsilon) { #define PerceptibleImageTag "Perceptible/Image" CacheView *image_view; ExceptionInfo *exception; MagickBooleanType status; MagickOffsetType progress; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (image->storage_class == PseudoClass) { register ssize_t i; register PixelPacket *magick_restrict q; q=image->colormap; for (i=0; i < (ssize_t) image->colors; i++) { SetPixelRed(q,PerceptibleThreshold(GetPixelRed(q),epsilon)); SetPixelGreen(q,PerceptibleThreshold(GetPixelGreen(q),epsilon)); SetPixelBlue(q,PerceptibleThreshold(GetPixelBlue(q),epsilon)); SetPixelOpacity(q,PerceptibleThreshold(GetPixelOpacity(q),epsilon)); q++; } return(SyncImage(image)); } /* Perceptible image. */ status=MagickTrue; progress=0; exception=(&image->exception); image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register IndexPacket *magick_restrict indexes; register ssize_t x; register PixelPacket *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (PixelPacket *) NULL) { status=MagickFalse; continue; } indexes=GetCacheViewAuthenticIndexQueue(image_view); for (x=0; x < (ssize_t) image->columns; x++) { if ((channel & RedChannel) != 0) SetPixelRed(q,PerceptibleThreshold(GetPixelRed(q),epsilon)); if ((channel & GreenChannel) != 0) SetPixelGreen(q,PerceptibleThreshold(GetPixelGreen(q),epsilon)); if ((channel & BlueChannel) != 0) SetPixelBlue(q,PerceptibleThreshold(GetPixelBlue(q),epsilon)); if ((channel & OpacityChannel) != 0) SetPixelOpacity(q,PerceptibleThreshold(GetPixelOpacity(q),epsilon)); if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace)) SetPixelIndex(indexes+x,PerceptibleThreshold(GetPixelIndex(indexes+x), epsilon)); q++; } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,PerceptibleImageTag,progress, image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % R a n d o m T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % RandomThresholdImage() changes the value of individual pixels based on the % intensity of each pixel compared to a random threshold. The result is a % low-contrast, two color image. % % The format of the RandomThresholdImage method is: % % MagickBooleanType RandomThresholdImageChannel(Image *image, % const char *thresholds,ExceptionInfo *exception) % MagickBooleanType RandomThresholdImageChannel(Image *image, % const ChannelType channel,const char *thresholds, % ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o channel: the channel or channels to be thresholded. % % o thresholds: a geometry string containing low,high thresholds. If the % string contains 2x2, 3x3, or 4x4, an ordered dither of order 2, 3, or 4 % is performed instead. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType RandomThresholdImage(Image *image, const char *thresholds,ExceptionInfo *exception) { MagickBooleanType status; status=RandomThresholdImageChannel(image,DefaultChannels,thresholds, exception); return(status); } MagickExport MagickBooleanType RandomThresholdImageChannel(Image *image, const ChannelType channel,const char *thresholds,ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" CacheView *image_view; GeometryInfo geometry_info; MagickStatusType flags; MagickBooleanType status; MagickOffsetType progress; MagickPixelPacket threshold; MagickRealType min_threshold, max_threshold; RandomInfo **magick_restrict random_info; ssize_t y; #if defined(MAGICKCORE_OPENMP_SUPPORT) unsigned long key; #endif assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickCoreSignature); if (thresholds == (const char *) NULL) return(MagickTrue); GetMagickPixelPacket(image,&threshold); min_threshold=0.0; max_threshold=(MagickRealType) QuantumRange; flags=ParseGeometry(thresholds,&geometry_info); min_threshold=geometry_info.rho; max_threshold=geometry_info.sigma; if ((flags & SigmaValue) == 0) max_threshold=min_threshold; if (strchr(thresholds,'%') != (char *) NULL) { max_threshold*=(MagickRealType) (0.01*QuantumRange); min_threshold*=(MagickRealType) (0.01*QuantumRange); } else if (((max_threshold == min_threshold) || (max_threshold == 1)) && (min_threshold <= 8)) { /* Backward Compatibility -- ordered-dither -- IM v 6.2.9-6. */ status=OrderedPosterizeImageChannel(image,channel,thresholds,exception); return(status); } /* Random threshold image. */ status=MagickTrue; progress=0; if (channel == CompositeChannels) { if (AcquireImageColormap(image,2) == MagickFalse) ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed", image->filename); random_info=AcquireRandomInfoThreadSet(); image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) key=GetRandomSecretKey(random_info[0]); #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,image,image->rows,key == ~0UL) #endif for (y=0; y < (ssize_t) image->rows; y++) { const int id = GetOpenMPThreadId(); MagickBooleanType sync; register IndexPacket *magick_restrict indexes; register ssize_t x; register PixelPacket *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1, exception); if (q == (PixelPacket *) NULL) { status=MagickFalse; continue; } indexes=GetCacheViewAuthenticIndexQueue(image_view); for (x=0; x < (ssize_t) image->columns; x++) { IndexPacket index; MagickRealType intensity; intensity=GetPixelIntensity(image,q); if (intensity < min_threshold) threshold.index=min_threshold; else if (intensity > max_threshold) threshold.index=max_threshold; else threshold.index=(MagickRealType)(QuantumRange* GetPseudoRandomValue(random_info[id])); index=(IndexPacket) (intensity <= threshold.index ? 0 : 1); SetPixelIndex(indexes+x,index); SetPixelRGBO(q,image->colormap+(ssize_t) index); q++; } sync=SyncCacheViewAuthenticPixels(image_view,exception); if (sync == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,ThresholdImageTag,progress, image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); random_info=DestroyRandomInfoThreadSet(random_info); return(status); } if (SetImageStorageClass(image,DirectClass) == MagickFalse) { InheritException(exception,&image->exception); return(MagickFalse); } random_info=AcquireRandomInfoThreadSet(); image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) key=GetRandomSecretKey(random_info[0]); #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,image,image->rows,key == ~0UL) #endif for (y=0; y < (ssize_t) image->rows; y++) { const int id = GetOpenMPThreadId(); register IndexPacket *magick_restrict indexes; register PixelPacket *magick_restrict q; register ssize_t x; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (PixelPacket *) NULL) { status=MagickFalse; continue; } indexes=GetCacheViewAuthenticIndexQueue(image_view); for (x=0; x < (ssize_t) image->columns; x++) { if ((channel & RedChannel) != 0) { if ((MagickRealType) GetPixelRed(q) < min_threshold) threshold.red=min_threshold; else if ((MagickRealType) GetPixelRed(q) > max_threshold) threshold.red=max_threshold; else threshold.red=(MagickRealType) (QuantumRange* GetPseudoRandomValue(random_info[id])); } if ((channel & GreenChannel) != 0) { if ((MagickRealType) GetPixelGreen(q) < min_threshold) threshold.green=min_threshold; else if ((MagickRealType) GetPixelGreen(q) > max_threshold) threshold.green=max_threshold; else threshold.green=(MagickRealType) (QuantumRange* GetPseudoRandomValue(random_info[id])); } if ((channel & BlueChannel) != 0) { if ((MagickRealType) GetPixelBlue(q) < min_threshold) threshold.blue=min_threshold; else if ((MagickRealType) GetPixelBlue(q) > max_threshold) threshold.blue=max_threshold; else threshold.blue=(MagickRealType) (QuantumRange* GetPseudoRandomValue(random_info[id])); } if ((channel & OpacityChannel) != 0) { if ((MagickRealType) GetPixelOpacity(q) < min_threshold) threshold.opacity=min_threshold; else if ((MagickRealType) GetPixelOpacity(q) > max_threshold) threshold.opacity=max_threshold; else threshold.opacity=(MagickRealType) (QuantumRange* GetPseudoRandomValue(random_info[id])); } if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace)) { if ((MagickRealType) GetPixelIndex(indexes+x) < min_threshold) threshold.index=min_threshold; else if ((MagickRealType) GetPixelIndex(indexes+x) > max_threshold) threshold.index=max_threshold; else threshold.index=(MagickRealType) (QuantumRange* GetPseudoRandomValue(random_info[id])); } if ((channel & RedChannel) != 0) SetPixelRed(q,(MagickRealType) GetPixelRed(q) <= threshold.red ? 0 : QuantumRange); if ((channel & GreenChannel) != 0) SetPixelGreen(q,(MagickRealType) GetPixelGreen(q) <= threshold.green ? 0 : QuantumRange); if ((channel & BlueChannel) != 0) SetPixelBlue(q,(MagickRealType) GetPixelBlue(q) <= threshold.blue ? 0 : QuantumRange); if ((channel & OpacityChannel) != 0) SetPixelOpacity(q,(MagickRealType) GetPixelOpacity(q) <= threshold.opacity ? 0 : QuantumRange); if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace)) SetPixelIndex(indexes+x,(MagickRealType) GetPixelIndex(indexes+x) <= threshold.index ? 0 : QuantumRange); q++; } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,ThresholdImageTag,progress,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); random_info=DestroyRandomInfoThreadSet(random_info); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % W h i t e T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % WhiteThresholdImage() is like ThresholdImage() but forces all pixels above % the threshold into white while leaving all pixels at or below the threshold % unchanged. % % The format of the WhiteThresholdImage method is: % % MagickBooleanType WhiteThresholdImage(Image *image,const char *threshold) % MagickBooleanType WhiteThresholdImageChannel(Image *image, % const ChannelType channel,const char *threshold, % ExceptionInfo *exception) % % A description of each parameter follows: % % o image: the image. % % o channel: the channel or channels to be thresholded. % % o threshold: Define the threshold value. % % o exception: return any errors or warnings in this structure. % */ MagickExport MagickBooleanType WhiteThresholdImage(Image *image, const char *threshold) { MagickBooleanType status; status=WhiteThresholdImageChannel(image,DefaultChannels,threshold, &image->exception); return(status); } MagickExport MagickBooleanType WhiteThresholdImageChannel(Image *image, const ChannelType channel,const char *thresholds,ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" CacheView *image_view; GeometryInfo geometry_info; MagickBooleanType status; MagickOffsetType progress; MagickPixelPacket threshold; MagickStatusType flags; ssize_t y; assert(image != (Image *) NULL); assert(image->signature == MagickCoreSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (thresholds == (const char *) NULL) return(MagickTrue); if (SetImageStorageClass(image,DirectClass) == MagickFalse) return(MagickFalse); flags=ParseGeometry(thresholds,&geometry_info); GetMagickPixelPacket(image,&threshold); threshold.red=geometry_info.rho; threshold.green=geometry_info.sigma; if ((flags & SigmaValue) == 0) threshold.green=threshold.red; threshold.blue=geometry_info.xi; if ((flags & XiValue) == 0) threshold.blue=threshold.red; threshold.opacity=geometry_info.psi; if ((flags & PsiValue) == 0) threshold.opacity=threshold.red; threshold.index=geometry_info.chi; if ((flags & ChiValue) == 0) threshold.index=threshold.red; if ((flags & PercentValue) != 0) { threshold.red*=(MagickRealType) (QuantumRange/100.0); threshold.green*=(MagickRealType) (QuantumRange/100.0); threshold.blue*=(MagickRealType) (QuantumRange/100.0); threshold.opacity*=(MagickRealType) (QuantumRange/100.0); threshold.index*=(MagickRealType) (QuantumRange/100.0); } if ((IsMagickGray(&threshold) == MagickFalse) && (IsGrayColorspace(image->colorspace) != MagickFalse)) (void) SetImageColorspace(image,sRGBColorspace); /* White threshold image. */ status=MagickTrue; progress=0; image_view=AcquireAuthenticCacheView(image,exception); #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp parallel for schedule(static) shared(progress,status) \ magick_number_threads(image,image,image->rows,1) #endif for (y=0; y < (ssize_t) image->rows; y++) { register IndexPacket *magick_restrict indexes; register ssize_t x; register PixelPacket *magick_restrict q; if (status == MagickFalse) continue; q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception); if (q == (PixelPacket *) NULL) { status=MagickFalse; continue; } indexes=GetCacheViewAuthenticIndexQueue(image_view); for (x=0; x < (ssize_t) image->columns; x++) { if (((channel & RedChannel) != 0) && ((MagickRealType) GetPixelRed(q) > threshold.red)) SetPixelRed(q,QuantumRange); if (((channel & GreenChannel) != 0) && ((MagickRealType) GetPixelGreen(q) > threshold.green)) SetPixelGreen(q,QuantumRange); if (((channel & BlueChannel) != 0) && ((MagickRealType) GetPixelBlue(q) > threshold.blue)) SetPixelBlue(q,QuantumRange); if (((channel & OpacityChannel) != 0) && ((MagickRealType) GetPixelOpacity(q) > threshold.opacity)) SetPixelOpacity(q,QuantumRange); if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace) && ((MagickRealType) GetPixelIndex(indexes+x)) > threshold.index) SetPixelIndex(indexes+x,QuantumRange); q++; } if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse) status=MagickFalse; if (image->progress_monitor != (MagickProgressMonitor) NULL) { MagickBooleanType proceed; #if defined(MAGICKCORE_OPENMP_SUPPORT) #pragma omp atomic #endif progress++; proceed=SetImageProgress(image,ThresholdImageTag,progress,image->rows); if (proceed == MagickFalse) status=MagickFalse; } } image_view=DestroyCacheView(image_view); return(status); }