/* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % 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 % % % % % % ImageMagick Image Threshold Methods % % % % Software Design % % John Cristy % % October 1996 % % % % % % Copyright 1999-2007 ImageMagick Studio LLC, a non-profit organization % % dedicated to making software imaging solutions freely available. % % % % You may not use this file except in compliance with the License. You may % % obtain a copy of the License at % % % % http://www.imagemagick.org/script/license.php % % % % Unless required by applicable law or agreed to in writing, software % % distributed under the License is distributed on an "AS IS" BASIS, % % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. % % See the License for the specific language governing permissions and % % limitations under the License. % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % */ /* Include declarations. */ #include "magick/studio.h" #include "magick/property.h" #include "magick/blob.h" #include "magick/cache-view.h" #include "magick/color.h" #include "magick/color-private.h" #include "magick/colorspace.h" #include "magick/configure.h" #include "magick/constitute.h" #include "magick/decorate.h" #include "magick/draw.h" #include "magick/enhance.h" #include "magick/exception.h" #include "magick/exception-private.h" #include "magick/effect.h" #include "magick/fx.h" #include "magick/gem.h" #include "magick/geometry.h" #include "magick/image-private.h" #include "magick/list.h" #include "magick/log.h" #include "magick/memory_.h" #include "magick/monitor.h" #include "magick/montage.h" #include "magick/pixel-private.h" #include "magick/quantize.h" #include "magick/quantum.h" #include "magick/random_.h" #include "magick/resize.h" #include "magick/resource_.h" #include "magick/segment.h" #include "magick/shear.h" #include "magick/signature.h" #include "magick/string_.h" #include "magick/transform.h" #include "magick/threshold.h" #include "magick/option.h" #include "magick/xml-tree.h" /* Structure declatations. */ struct _ThresholdMap { char *map_id, *description; int width, height, divisor, *levels; }; /* Define declarations. */ #define ThresholdsFilename "thresholds.xml" /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % 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 unsigned long width,const unsigned long height, % const long 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 unsigned long width,const unsigned long height,const long offset, ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" Image *threshold_image; IndexPacket *indexes, *threshold_indexes; long u, v, y; MagickBooleanType status; MagickPixelPacket pixel, mean; MagickRealType number_pixels; register const PixelPacket *p, *r; register long x; register PixelPacket *q; /* Initialize thresholded image attributes. */ assert(image != (const Image *) NULL); assert(image->signature == MagickSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickSignature); if ((image->columns < width) || (image->rows < height)) ThrowImageException(OptionError,"ImageSmallerThanRadius"); threshold_image=CloneImage(image,0,0,MagickTrue,exception); if (threshold_image == (Image *) NULL) return((Image *) NULL); if (SetImageStorageClass(threshold_image,DirectClass) == MagickFalse) { InheritException(exception,&threshold_image->exception); threshold_image=DestroyImage(threshold_image); return((Image *) NULL); } /* Threshold each row of the image. */ GetMagickPixelPacket(image,&mean); number_pixels=(MagickRealType) (width*height); for (y=0; y < (long) image->rows; y++) { p=AcquireImagePixels(image,-((long) width/2L),y-height/2L,image->columns+ width,height,exception); q=GetImagePixels(threshold_image,0,y,threshold_image->columns,1); if ((p == (const PixelPacket *) NULL) || (q == (PixelPacket *) NULL)) break; indexes=GetIndexes(image); threshold_indexes=GetIndexes(threshold_image); for (x=0; x < (long) image->columns; x++) { GetMagickPixelPacket(image,&pixel); r=p; for (v=0; v < (long) height; v++) { for (u=0; u < (long) width; u++) { pixel.red+=r[u].red; pixel.green+=r[u].green; pixel.blue+=r[u].blue; pixel.opacity+=r[u].opacity; if (image->colorspace == CMYKColorspace) pixel.index=(MagickRealType) indexes[x+(r-p)+u]; } r+=image->columns+width; } mean.red=(MagickRealType) (pixel.red/number_pixels+offset); mean.green=(MagickRealType) (pixel.green/number_pixels+offset); mean.blue=(MagickRealType) (pixel.blue/number_pixels+offset); mean.opacity=(MagickRealType) (pixel.opacity/number_pixels+offset); if (image->colorspace == CMYKColorspace) mean.index=(MagickRealType) (pixel.index/number_pixels+offset); q->red=(Quantum) (((MagickRealType) q->red <= mean.red) ? 0 : QuantumRange); q->green=(Quantum) (((MagickRealType) q->green <= mean.green) ? 0 : QuantumRange); q->blue=(Quantum) (((MagickRealType) q->blue <= mean.blue) ? 0 : QuantumRange); q->opacity=(Quantum) (((MagickRealType) q->opacity <= mean.opacity) ? 0 : QuantumRange); if (image->colorspace == CMYKColorspace) threshold_indexes[x]=(IndexPacket) (((MagickRealType) threshold_indexes[x] <= mean.index) ? 0 : QuantumRange); p++; q++; } if (SyncImagePixels(threshold_image) == MagickFalse) break; if ((image->progress_monitor != (MagickProgressMonitor) NULL) && (QuantumTick(y,image->rows) != MagickFalse)) { status=image->progress_monitor(ThresholdImageTag,y,image->rows, image->client_data); if (status == MagickFalse) break; } } return(threshold_image); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % B i l e v e l I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % BilevelImage() changes the value of individual pixels based on the % intensity of each pixel channel. The result is a high-contrast image. % % 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. % */ 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" long y; MagickBooleanType status; register IndexPacket *indexes; register long x; register PixelPacket *q; /* Threshold image. */ assert(image != (Image *) NULL); assert(image->signature == MagickSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (SetImageStorageClass(image,DirectClass) == MagickFalse) return(MagickFalse); for (y=0; y < (long) image->rows; y++) { q=GetImagePixels(image,0,y,image->columns,1); if (q == (PixelPacket *) NULL) break; indexes=GetIndexes(image); if (channel == DefaultChannels) { for (x=0; x < (long) image->columns; x++) { q->red=(Quantum) ((MagickRealType) PixelIntensityToQuantum(q) <= threshold ? 0 : QuantumRange); q->green=q->red; q->blue=q->red; q++; } } else for (x=0; x < (long) image->columns; x++) { if ((channel & RedChannel) != 0) q->red=(Quantum) ((MagickRealType) q->red <= threshold ? 0 : QuantumRange); if ((channel & GreenChannel) != 0) q->green=(Quantum) ((MagickRealType) q->green <= threshold ? 0 : QuantumRange); if ((channel & BlueChannel) != 0) q->blue=(Quantum) ((MagickRealType) q->blue <= threshold ? 0 : QuantumRange); if ((channel & OpacityChannel) != 0) { if (image->matte == MagickFalse) q->opacity=(Quantum) ((MagickRealType) q->opacity <= threshold ? 0 : QuantumRange); else q->opacity=(Quantum) ((MagickRealType) q->opacity <= threshold ? OpaqueOpacity : TransparentOpacity); } if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace)) indexes[x]=(IndexPacket) ((MagickRealType) indexes[x] <= threshold ? 0 : QuantumRange); q++; } if (SyncImagePixels(image) == MagickFalse) break; if ((image->progress_monitor != (MagickProgressMonitor) NULL) && (QuantumTick(y,image->rows) != MagickFalse)) { status=image->progress_monitor(ThresholdImageTag,y,image->rows, image->client_data); if (status == MagickFalse) break; } } return(MagickTrue); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % 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 above the threshold % unchanged. % % The format of the BlackThresholdImage method is: % % MagickBooleanType BlackThresholdImage(Image *image,const char *threshold) % % A description of each parameter follows: % % o image: The image. % % o threshold: Define the threshold value. % */ MagickExport MagickBooleanType BlackThresholdImage(Image *image, const char *threshold) { #define ThresholdImageTag "Threshold/Image" GeometryInfo geometry_info; long y; MagickBooleanType status; MagickPixelPacket pixel; MagickStatusType flags; register long x; register PixelPacket *q; /* Threshold image. */ assert(image != (Image *) NULL); assert(image->signature == MagickSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (threshold == (const char *) NULL) return(MagickTrue); if (SetImageStorageClass(image,DirectClass) == MagickFalse) return(MagickFalse); GetMagickPixelPacket(image,&pixel); flags=ParseGeometry(threshold,&geometry_info); pixel.red=geometry_info.rho; pixel.green=geometry_info.sigma; if ((flags & SigmaValue) == 0) pixel.green=pixel.red; pixel.blue=geometry_info.xi; if ((flags & XiValue) == 0) pixel.blue=pixel.red; pixel.opacity=geometry_info.psi; if ((flags & PsiValue) == 0) pixel.opacity=(MagickRealType) OpaqueOpacity; if ((flags & PercentValue) != 0) { pixel.red*=QuantumRange/100.0f; pixel.green*=QuantumRange/100.0f; pixel.blue*=QuantumRange/100.0f; pixel.opacity*=QuantumRange/100.0f; } for (y=0; y < (long) image->rows; y++) { q=GetImagePixels(image,0,y,image->columns,1); if (q == (PixelPacket *) NULL) break; if (IsMagickGray(&pixel) != MagickFalse) for (x=0; x < (long) image->columns; x++) { if ((MagickRealType) PixelIntensityToQuantum(q) < pixel.red) { q->red=(Quantum) 0; q->green=(Quantum) 0; q->blue=(Quantum) 0; } q++; } else for (x=0; x < (long) image->columns; x++) { if ((MagickRealType) q->red < pixel.red) q->red=(Quantum) 0; if ((MagickRealType) q->green < pixel.green) q->green=(Quantum) 0; if ((MagickRealType) q->blue < pixel.blue) q->blue=(Quantum) 0; if ((MagickRealType) q->opacity < pixel.opacity) q->opacity=(Quantum) 0; q++; } if (SyncImagePixels(image) == MagickFalse) break; if ((image->progress_monitor != (MagickProgressMonitor) NULL) && (QuantumTick(y,image->rows) != MagickFalse)) { status=image->progress_monitor(ThresholdImageTag,y,image->rows, image->client_data); if (status == MagickFalse) break; } } return(MagickTrue); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % 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) { if ( map && map->description ) map->map_id = DestroyString(map->map_id); if ( map && map->description ) map->description = DestroyString(map->description); if ( map && map->levels ) map->levels = (int *) RelinquishMagickMemory(map->levels); if ( map ) map = (ThresholdMap *) RelinquishMagickMemory(map); return(map); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % + G e t T h r e s h o l d M a p F i l e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % GetThresholdMapFile() look for a given threshold map name or alias in the % given XML file data, and return the allocated the map when found. % % The format of the ListThresholdMaps method is: % % ThresholdMap *GetThresholdMap(const char *xml,const char *filename, % const char *map_id,ExceptionInfo *exception) % % A description of each parameter follows. % % o xml: The threshold map list in XML format. % % o filename: The threshold map XML filename. % % o map_id: ID of the map to look for in XML list. % % o exception: Return any errors or warnings in this structure. % */ MagickExport ThresholdMap *GetThresholdMapFile(const char *xml, const char *filename,const char *map_id,ExceptionInfo *exception) { const char *attr, *content; XMLTreeInfo *thresholds,*threshold,*description,*levels; ThresholdMap *map; map = (ThresholdMap *)NULL; (void) LogMagickEvent(ConfigureEvent,GetMagickModule(), "Loading threshold map file \"%s\" ...",filename); thresholds=NewXMLTree(xml,exception); if ( thresholds == (XMLTreeInfo *)NULL ) return(map); for( threshold = GetXMLTreeChild(thresholds,"threshold"); threshold != (XMLTreeInfo *)NULL; threshold = GetNextXMLTreeTag(threshold) ) { attr = GetXMLTreeAttribute(threshold, "map"); if ( (attr != (char *)NULL) && (LocaleCompare(map_id,attr) == 0) ) break; attr = GetXMLTreeAttribute(threshold, "alias"); if ( (attr != (char *)NULL) && (LocaleCompare(map_id,attr) == 0) ) break; } if ( threshold == (XMLTreeInfo *)NULL ) { return(map); } description = GetXMLTreeChild(threshold,"description"); if ( description == (XMLTreeInfo *)NULL ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingElement", ", 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 = (int *)NULL; /* Assign Basic Attributes */ attr = GetXMLTreeAttribute(threshold, "map"); if ( attr != (char *)NULL ) map->map_id = ConstantString(attr); content = GetXMLTreeContent(description); if ( content != (char *)NULL ) map->description = ConstantString(content); attr = GetXMLTreeAttribute(levels, "width"); if ( attr == (char *)NULL ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingAttribute", ", map \"%s\"", map_id); thresholds = DestroyXMLTree(thresholds); map = DestroyThresholdMap(map); return(map); } map->width = atoi(attr); if ( map->width == 0 ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlInvalidAttribute", ", map \"%s\"", map_id); thresholds = DestroyXMLTree(thresholds); map = DestroyThresholdMap(map); return(map); } attr = GetXMLTreeAttribute(levels, "height"); if ( attr == (char *)NULL ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingAttribute", ", map \"%s\"", map_id); thresholds = DestroyXMLTree(thresholds); map = DestroyThresholdMap(map); return(map); } map->height = atoi(attr); if ( map->height == 0 ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlInvalidAttribute", ", map \"%s\"", map_id); thresholds = DestroyXMLTree(thresholds); map = DestroyThresholdMap(map); return(map); } attr = GetXMLTreeAttribute(levels, "divisor"); if ( attr == (char *)NULL ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingAttribute", ", map \"%s\"", map_id); thresholds = DestroyXMLTree(thresholds); map = DestroyThresholdMap(map); return(map); } map->divisor = atoi(attr); if ( map->divisor < 2 ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlInvalidAttribute", ", map \"%s\"", map_id); thresholds = DestroyXMLTree(thresholds); map = DestroyThresholdMap(map); return(map); } /* Allocate the 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=(int *) AcquireQuantumMemory((size_t) map->width,map->height* sizeof(*map->levels)); if ( map->levels == (int *)NULL ) ThrowFatalException(ResourceLimitFatalError,"UnableToAcquireThresholdMap"); { /* parse levels into integer array */ int i; char *p; for( i=0; iwidth*map->height; i++) { map->levels[i] = (int)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", " %d out of range, map \"%s\"", map->levels[i], map_id); thresholds = DestroyXMLTree(thresholds); map = DestroyThresholdMap(map); return(map); } content = p; } (void) strtol(content, &p, 10); 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=(ThresholdMap *)NULL; options=GetConfigureOptions(ThresholdsFilename,exception); while (( option=(const StringInfo *) GetNextValueInLinkedList(options) ) != (const StringInfo *) NULL && map == (ThresholdMap *)NULL ) map=GetThresholdMapFile((const char *) GetStringInfoDatum(option), GetStringInfoPath(option),map_id,exception); options=DestroyConfigureOptions(options); return(map); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % + L i s t T h r e s h o l d M a p F i l e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % ListThresholdMapFile() lists the threshold maps and their descriptions % in the given XML file data. % % The format of the ListThresholdMaps method is: % % MagickBooleanType ListThresholdMaps(FILE *file,const char*xml, % const char *filename,ExceptionInfo *exception) % % A description of each parameter follows. % % o file: An pointer to the output FILE. % % o xml: The threshold map list in XML format. % % o filename: The threshold map XML filename. % % o exception: Return any errors or warnings in this structure. % */ MagickBooleanType ListThresholdMapFile(FILE *file,const char *xml, const char *filename,ExceptionInfo *exception) { XMLTreeInfo *thresholds,*threshold,*description; const char *map,*alias,*content; assert( xml != (char *)NULL ); assert( file != (FILE *)NULL ); (void) LogMagickEvent(ConfigureEvent,GetMagickModule(), "Loading threshold map file \"%s\" ...",filename); thresholds=NewXMLTree(xml,exception); if ( thresholds == (XMLTreeInfo *)NULL ) return(MagickFalse); (void) fprintf(file,"%-16s %-12s %s\n", "Map", "Alias", "Description"); (void) fprintf(file,"----------------------------------------------------\n"); for( threshold = GetXMLTreeChild(thresholds,"threshold"); threshold != (XMLTreeInfo *)NULL; threshold = GetNextXMLTreeTag(threshold) ) { map = GetXMLTreeAttribute(threshold, "map"); if (map == (char *) NULL) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "XmlMissingAttribute", ""); 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) fprintf(file,"%-16s %-12s %s\n",map,alias ? alias : "", content); } thresholds=DestroyXMLTree(thresholds); return(MagickTrue); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % L i s t T h r e s h o l d M a p s % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % ListThresholdMaps() lists the threshold maps and their descriptions % as defined by "threshold.xml" to a file. % % The format of the ListThresholdMaps method is: % % MagickBooleanType ListThresholdMaps(FILE *file,ExceptionInfo *exception) % % A description of each parameter follows. % % o file: An pointer to the output FILE. % % o exception: Return any errors or warnings in this structure. % */ MagickExport MagickBooleanType ListThresholdMaps(FILE *file, ExceptionInfo *exception) { const StringInfo *option; LinkedListInfo *options; MagickStatusType status; status=MagickFalse; if ( file == (FILE *)NULL ) file = stdout; options=GetConfigureOptions(ThresholdsFilename,exception); (void) fprintf(file, "\n Threshold Maps for Ordered Dither Operations\n"); while ( ( option=(const StringInfo *) GetNextValueInLinkedList(options) ) != (const StringInfo *) NULL) { (void) fprintf(file,"\nPATH: %s\n\n",GetStringInfoPath(option)); status|=ListThresholdMapFile(file,(const char *) GetStringInfoDatum(option), GetStringInfoPath(option),exception); } options=DestroyConfigureOptions(options); return(status != 0 ? MagickTrue : MagickFalse); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % O r d e r e d D i t h e r I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % OrderedDitherImage() uses the ordered dithering technique of reducing color % images to monochrome using positional information to retain as much % information as possible. % % WARNING: This function is depreciated, and is now just a call to % the more more powerful OrderedPosterizeImage(); function. % % The format of the OrderedDitherImage method is: % % MagickBooleanType OrderedDitherImage(Image *image) % MagickBooleanType OrderedDitherImageChannel(Image *image, % const ChannelType channel,ExceptionInfo *exception) % % A description of each parameter follows: % % o image: The image. % % o channel: The channel or channels to be thresholded. % % o exception: Return any errors or warnings in this structure. % */ MagickExport MagickBooleanType OrderedDitherImage(Image *image) { MagickBooleanType status; status=OrderedDitherImageChannel(image,DefaultChannels,&image->exception); return(status); } MagickExport MagickBooleanType OrderedDitherImageChannel(Image *image, const ChannelType channel,ExceptionInfo *exception) { MagickBooleanType status; /* Call the augumented function OrderedPosterizeImage() */ status=OrderedPosterizeImageChannel(image,channel,"o8x8",exception); return(status); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % O r d e r e d P o s t e r i z e I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % OrderedPosterizeImage() will perform a ordered dither based on a number % of pre-defined dithering threshold maps, but over multiple intensity % levels, which can be different for different channels, according to the % input argument. % % The format of the OrderedPosterizeImage method is: % % MagickBooleanType OrderedPosterizeImage(Image *image, % const char *threshold_map,ExceptionInfo *exception) % MagickBooleanType OrderedPosterizeImageChannel(Image *image, % const ChannelType channel,const char *threshold_map, % ExceptionInfo *exception) % % A description of each parameter follows: % % o image: The image. % % o channel: The channel or channels to be thresholded. % % o threshold_map: A string containing the name of the threshold dither % map to use, followed by zero or more numbers representing the number % of color levels tho dither between. % % Any level number less than 2 will be equivelent to 2, and means only % binary dithering will be applied to each color channel. % % No numbers also means a 2 level (bitmap) dither will be applied to all % channels, while a single number is the number of levels applied to each % channel in sequence. More numbers will be applied in turn to each of % the color channels. % % For example: "o3x3,6" will generate a 6 level posterization of the % image with a ordered 3x3 diffused pixel dither being applied between % each level. While checker,8,8,4 will produce a 332 colormaped image % with only a single checkerboard hash pattern (50% grey) between each % color level, to basically double the number of color levels with % a bare minimim of dithering. % % o exception: Return any errors or warnings in this structure. % */ MagickExport MagickBooleanType OrderedPosterizeImage(Image *image, const char *threshold_map,ExceptionInfo *exception) { MagickBooleanType status; status=OrderedPosterizeImageChannel(image,DefaultChannels,threshold_map, exception); return(status); } MagickExport MagickBooleanType OrderedPosterizeImageChannel(Image *image, const ChannelType channel,const char *threshold_map,ExceptionInfo *exception) { #define DitherImageTag "Dither/Image" ThresholdMap *map; LongPixelPacket levels; long y; register long x; register IndexPacket *indexes; assert(image != (Image *) NULL); assert(image->signature == MagickSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickSignature); if (threshold_map == (const char *) NULL) return(MagickTrue); { char token[MaxTextExtent], *p; p=(char *)threshold_map; while (((isspace((int) ((unsigned char) *p)) != 0) || (*p == ',')) && (*p != '\0')) p++; threshold_map=p; while (((isspace((int) ((unsigned char) *p)) == 0) && (*p != ',')) && (*p != '\0')) { if ((p-threshold_map) >= MaxTextExtent) break; token[p-threshold_map] = *p; p++; } token[p-threshold_map] = '\0'; map = GetThresholdMap(token, exception); if ( map == (ThresholdMap *)NULL ) { (void) ThrowMagickException(exception,GetMagickModule(),OptionError, "InvalidArgument","%s : '%s'","ordered-dither",threshold_map); return(MagickFalse); } } /* Set channel levels from extra comma seperated arguments Default to 2, or single value given, or individual channel values */ #if 1 { /* parse directly as a comma seperated list of integers */ char *p; p = strchr(threshold_map,','); if ( p != (char *)NULL && isdigit((int) ((unsigned char) *(++p))) ) levels.index = 1UL*strtol(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(threshold_map,','); p++; if ((channel & RedChannel) != 0) levels.red = (unsigned long) strtol(p, &p, 10), (void)(*p == ',' && p++); if ((channel & GreenChannel) != 0) levels.green = (unsigned long) strtol(p, &p, 10), (void)(*p == ',' && p++); if ((channel & BlueChannel) != 0) levels.blue = (unsigned long) strtol(p, &p, 10), (void)(*p == ',' && p++); if ((channel & OpacityChannel) != 0) levels.opacity = (unsigned long) strtol(p, &p, 10), (void)(*p == ',' && p++); if ((channel & IndexChannel) != 0 && image->colorspace == CMYKColorspace) levels.index=(unsigned long) strtol(p, &p, 10), (void)(*p == ',' && p++); } } #else /* Parse level values as a geometry */ /* This is 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 long pixel packet. */ #endif #if 0 printf("DEBUG levels r=%ld g=%ld b=%ld a=%ld i=%ld\n", levels.red, levels.green, levels.blue, levels.opacity, levels.index); #endif { /* Do the posterized ordered dithering of the image */ int 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); } for (y=0; y < (long) image->rows; y++) { register PixelPacket *q; q=GetImagePixels(image,0,y,image->columns,1); if (q == (PixelPacket *) NULL) break; indexes=GetIndexes(image); for (x=0; x < (long) image->columns; x++) { register int 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 = (int) (QuantumScale*q->red*(levels.red*d+1)); l = t/d; t = t-l*d; q->red=(Quantum) ((l+(t >= threshold))*QuantumRange/levels.red); } if (levels.green) { t = (int) (QuantumScale*q->green*(levels.green*d+1)); l = t/d; t = t-l*d; q->green=(Quantum) ((l+(t >= threshold))*QuantumRange/levels.green); } if (levels.blue) { t = (int) (QuantumScale*q->blue*(levels.blue*d+1)); l = t/d; t = t-l*d; q->blue=(Quantum) ((l+(t >= threshold))*QuantumRange/levels.blue); } if (levels.opacity) { t = (int) ((1.0-QuantumScale*q->opacity)*(levels.opacity*d+1)); l = t/d; t = t-l*d; q->opacity=(Quantum) ((1.0-l-(t >= threshold))*QuantumRange/ levels.opacity); } if (levels.index) { t = (int) (QuantumScale*indexes[x]*(levels.index*d+1)); l = t/d; t = t-l*d; indexes[x]=(IndexPacket) ((l+(t>=threshold))*QuantumRange/ levels.index); } q++; } if (SyncImagePixels(image) == MagickFalse) break; if ((image->progress_monitor != (MagickProgressMonitor) NULL) && (QuantumTick(y,image->rows) != MagickFalse)) { MagickBooleanType status=image->progress_monitor(DitherImageTag,y,image->rows, image->client_data); if (status == MagickFalse) break; } } } map=DestroyThresholdMap(map); return(MagickTrue); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % R a n d o m T h r e s h o l d I m a g e % % % % % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % RandomThresholdImage() changes the value of individual pixels based on the % intensity of each pixel compared to a random threshold. The result is a % low-contrast, two color image. % % The format of the RandomThresholdImage method is: % % MagickBooleanType RandomThresholdImageChannel(Image *image, % const char *thresholds,ExceptionInfo *exception) % MagickBooleanType RandomThresholdImageChannel(Image *image, % const ChannelType channel,const char *thresholds, % ExceptionInfo *exception) % % A description of each parameter follows: % % o image: The image. % % o channel: The channel or channels to be thresholded. % % o thresholds: a geometry string containing low,high thresholds. If the % string contains 2x2, 3x3, or 4x4, an ordered dither of order 2, 3, or 4 % is performed instead. % % o exception: Return any errors or warnings in this structure. % */ MagickExport MagickBooleanType RandomThresholdImage(Image *image, const char *thresholds,ExceptionInfo *exception) { MagickBooleanType status; status=RandomThresholdImageChannel(image,DefaultChannels,thresholds, exception); return(status); } MagickExport MagickBooleanType RandomThresholdImageChannel(Image *image, const ChannelType channel,const char *thresholds,ExceptionInfo *exception) { #define ThresholdImageTag "Threshold/Image" GeometryInfo geometry_info; MagickStatusType flags; long y; MagickBooleanType status; MagickPixelPacket threshold; MagickRealType min_threshold, max_threshold; register long x; register IndexPacket *indexes; register PixelPacket *q; assert(image != (Image *) NULL); assert(image->signature == MagickSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); assert(exception != (ExceptionInfo *) NULL); assert(exception->signature == MagickSignature); if (thresholds == (const char *) NULL) return(MagickTrue); GetMagickPixelPacket(image,&threshold); min_threshold=0.0; max_threshold=(MagickRealType) QuantumRange; flags=ParseGeometry(thresholds,&geometry_info); min_threshold=geometry_info.rho; max_threshold=geometry_info.sigma; if ((flags & SigmaValue) == 0) max_threshold=min_threshold; if (strchr(thresholds,'%') != (char *) NULL) { max_threshold*=(0.01f*QuantumRange); min_threshold*=(0.01f*QuantumRange); } else if ( min_threshold <= 8 && (max_threshold == min_threshold || max_threshold == 1 ) ) { /* Backward Compatibility -- ordered-dither -- IM v 6.2.9-6 outputing a WARNING here may be appropriate -- discontinue in future */ status=OrderedPosterizeImageChannel(image,channel,thresholds,exception); return(status); } if (channel == AllChannels) { IndexPacket index; MagickRealType intensity; if (AllocateImageColormap(image,2) == MagickFalse) ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed", image->filename); for (y=0; y < (long) image->rows; y++) { q=GetImagePixels(image,0,y,image->columns,1); if (q == (PixelPacket *) NULL) break; indexes=GetIndexes(image); for (x=0; x < (long) image->columns; x++) { intensity=(MagickRealType) PixelIntensityToQuantum(q); if (intensity < min_threshold) threshold.index=min_threshold; else if (intensity > max_threshold) threshold.index=max_threshold; else threshold.index=(MagickRealType)(QuantumRange*GetRandomValue()); index=(IndexPacket) (intensity < threshold.index ? 0 : 1); indexes[x]=index; *q++=image->colormap[(long) index]; } if (SyncImagePixels(image) == MagickFalse) break; if ((image->progress_monitor != (MagickProgressMonitor) NULL) && (QuantumTick(y,image->rows) != MagickFalse)) { status=image->progress_monitor(ThresholdImageTag,y,image->rows, image->client_data); if (status == MagickFalse) break; } } return(MagickTrue); } if (SetImageStorageClass(image,DirectClass) == MagickFalse) { InheritException(exception,&image->exception); return(MagickFalse); } for (y=0; y < (long) image->rows; y++) { q=GetImagePixels(image,0,y,image->columns,1); if (q == (PixelPacket *) NULL) break; indexes=GetIndexes(image); for (x=0; x < (long) image->columns; x++) { if ((channel & RedChannel) != 0) { if ((MagickRealType) q->red < min_threshold) threshold.red=min_threshold; else if ((MagickRealType) q->red > max_threshold) threshold.red=max_threshold; else threshold.red=(MagickRealType) (QuantumRange* GetRandomValue()); } if ((channel & GreenChannel) != 0) { if ((MagickRealType) q->green < min_threshold) threshold.green=min_threshold; else if ((MagickRealType) q->green > max_threshold) threshold.green=max_threshold; else threshold.green=(MagickRealType) (QuantumRange* GetRandomValue()); } if ((channel & BlueChannel) != 0) { if ((MagickRealType) q->blue < min_threshold) threshold.blue=min_threshold; else if ((MagickRealType) q->blue > max_threshold) threshold.blue=max_threshold; else threshold.blue=(MagickRealType) (QuantumRange* GetRandomValue()); } if ((channel & OpacityChannel) != 0) { if ((MagickRealType) q->opacity < min_threshold) threshold.opacity=min_threshold; else if ((MagickRealType) q->opacity > max_threshold) threshold.opacity=max_threshold; else threshold.opacity=(MagickRealType) (QuantumRange* GetRandomValue()); } if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace)) { if ((MagickRealType) indexes[x] < min_threshold) threshold.index=min_threshold; else if ((MagickRealType) indexes[x] > max_threshold) threshold.index=max_threshold; else threshold.index=(MagickRealType) (QuantumRange* GetRandomValue()); } if ((channel & RedChannel) != 0) q->red=(Quantum) ((MagickRealType) q->red <= threshold.red ? 0 : QuantumRange); if ((channel & GreenChannel) != 0) q->green=(Quantum) ((MagickRealType) q->green <= threshold.green ? 0 : QuantumRange); if ((channel & BlueChannel) != 0) q->blue=(Quantum) ((MagickRealType) q->blue <= threshold.blue ? 0 : QuantumRange); if ((channel & OpacityChannel) != 0) q->opacity=(Quantum) ((MagickRealType) q->opacity <= threshold.opacity ? 0 : QuantumRange); if (((channel & IndexChannel) != 0) && (image->colorspace == CMYKColorspace)) indexes[x]=(IndexPacket) ((MagickRealType) indexes[x] <= threshold.index ? 0 : QuantumRange); q++; } if (SyncImagePixels(image) == MagickFalse) break; if ((image->progress_monitor != (MagickProgressMonitor) NULL) && (QuantumTick(y,image->rows) != MagickFalse)) { status=image->progress_monitor(ThresholdImageTag,y,image->rows, image->client_data); if (status == MagickFalse) break; } } return(MagickTrue); } /* %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % % % % % % 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 below the threshold % unchanged. % % The format of the WhiteThresholdImage method is: % % MagickBooleanType WhiteThresholdImage(Image *image,const char *threshold) % % A description of each parameter follows: % % o image: The image. % % o threshold: Define the threshold value % */ MagickExport MagickBooleanType WhiteThresholdImage(Image *image, const char *threshold) { #define ThresholdImageTag "Threshold/Image" GeometryInfo geometry_info; long y; MagickBooleanType status; MagickPixelPacket pixel; MagickStatusType flags; register long x; register PixelPacket *q; /* Threshold image. */ assert(image != (Image *) NULL); assert(image->signature == MagickSignature); if (image->debug != MagickFalse) (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); if (threshold == (const char *) NULL) return(MagickTrue); if (SetImageStorageClass(image,DirectClass) == MagickFalse) return(MagickFalse); GetMagickPixelPacket(image,&pixel); flags=ParseGeometry(threshold,&geometry_info); pixel.red=geometry_info.rho; pixel.green=geometry_info.sigma; if ((flags & SigmaValue) == 0) pixel.green=pixel.red; pixel.blue=geometry_info.xi; if ((flags & XiValue) == 0) pixel.blue=pixel.red; pixel.opacity=geometry_info.psi; if ((flags & PsiValue) == 0) pixel.opacity=(MagickRealType) OpaqueOpacity; if ((flags & PercentValue) != 0) { pixel.red*=QuantumRange/100.0f; pixel.green*=QuantumRange/100.0f; pixel.blue*=QuantumRange/100.0f; pixel.opacity*=QuantumRange/100.0f; } for (y=0; y < (long) image->rows; y++) { q=GetImagePixels(image,0,y,image->columns,1); if (q == (PixelPacket *) NULL) break; if (IsMagickGray(&pixel) != MagickFalse) for (x=0; x < (long) image->columns; x++) { if ((MagickRealType) PixelIntensityToQuantum(q) > pixel.red) { q->red=(Quantum) QuantumRange; q->green=(Quantum) QuantumRange; q->blue=(Quantum) QuantumRange; } q++; } else for (x=0; x < (long) image->columns; x++) { if ((MagickRealType) q->red > pixel.red) q->red=(Quantum) QuantumRange; if ((MagickRealType) q->green > pixel.green) q->green=(Quantum) QuantumRange; if ((MagickRealType) q->blue > pixel.blue) q->blue=(Quantum) QuantumRange; if ((MagickRealType) q->opacity > pixel.opacity) q->opacity=(Quantum) QuantumRange; q++; } if (SyncImagePixels(image) == MagickFalse) break; if ((image->progress_monitor != (MagickProgressMonitor) NULL) && (QuantumTick(y,image->rows) != MagickFalse)) { status=image->progress_monitor(ThresholdImageTag,y,image->rows, image->client_data); if (status == MagickFalse) break; } } return(MagickTrue); }