2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
6 % SSSSS H H EEEEE AAA RRRR %
8 % SSS HHHHH EEE AAAAA RRRR %
10 % SSSSS H H EEEEE A A R R %
13 % MagickCore Methods to Shear or Rotate an Image by an Arbitrary Angle %
20 % Copyright 1999-2011 ImageMagick Studio LLC, a non-profit organization %
21 % dedicated to making software imaging solutions freely available. %
23 % You may not use this file except in compliance with the License. You may %
24 % obtain a copy of the License at %
26 % http://www.imagemagick.org/script/license.php %
28 % Unless required by applicable law or agreed to in writing, software %
29 % distributed under the License is distributed on an "AS IS" BASIS, %
30 % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
31 % See the License for the specific language governing permissions and %
32 % limitations under the License. %
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
36 % The RotateImage, XShearImage, and YShearImage methods are based on the
37 % paper "A Fast Algorithm for General Raster Rotatation" by Alan W. Paeth,
38 % Graphics Interface '86 (Vancouver). RotateImage is adapted from a similar
39 % method based on the Paeth paper written by Michael Halle of the Spatial
40 % Imaging Group, MIT Media Lab.
48 #include "MagickCore/studio.h"
49 #include "MagickCore/artifact.h"
50 #include "MagickCore/attribute.h"
51 #include "MagickCore/blob-private.h"
52 #include "MagickCore/cache-private.h"
53 #include "MagickCore/color-private.h"
54 #include "MagickCore/colorspace-private.h"
55 #include "MagickCore/composite.h"
56 #include "MagickCore/composite-private.h"
57 #include "MagickCore/decorate.h"
58 #include "MagickCore/distort.h"
59 #include "MagickCore/draw.h"
60 #include "MagickCore/exception.h"
61 #include "MagickCore/exception-private.h"
62 #include "MagickCore/gem.h"
63 #include "MagickCore/geometry.h"
64 #include "MagickCore/image.h"
65 #include "MagickCore/image-private.h"
66 #include "MagickCore/memory_.h"
67 #include "MagickCore/list.h"
68 #include "MagickCore/monitor.h"
69 #include "MagickCore/monitor-private.h"
70 #include "MagickCore/pixel-accessor.h"
71 #include "MagickCore/quantum.h"
72 #include "MagickCore/resource_.h"
73 #include "MagickCore/shear.h"
74 #include "MagickCore/statistic.h"
75 #include "MagickCore/string_.h"
76 #include "MagickCore/string-private.h"
77 #include "MagickCore/thread-private.h"
78 #include "MagickCore/threshold.h"
79 #include "MagickCore/transform.h"
82 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
86 % A f f i n e T r a n s f o r m I m a g e %
90 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
92 % AffineTransformImage() transforms an image as dictated by the affine matrix.
93 % It allocates the memory necessary for the new Image structure and returns
94 % a pointer to the new image.
96 % The format of the AffineTransformImage method is:
98 % Image *AffineTransformImage(const Image *image,
99 % AffineMatrix *affine_matrix,ExceptionInfo *exception)
101 % A description of each parameter follows:
103 % o image: the image.
105 % o affine_matrix: the affine matrix.
107 % o exception: return any errors or warnings in this structure.
110 MagickExport Image *AffineTransformImage(const Image *image,
111 const AffineMatrix *affine_matrix,ExceptionInfo *exception)
120 Affine transform image.
122 assert(image->signature == MagickSignature);
123 if (image->debug != MagickFalse)
124 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
125 assert(affine_matrix != (AffineMatrix *) NULL);
126 assert(exception != (ExceptionInfo *) NULL);
127 assert(exception->signature == MagickSignature);
128 distort[0]=affine_matrix->sx;
129 distort[1]=affine_matrix->rx;
130 distort[2]=affine_matrix->ry;
131 distort[3]=affine_matrix->sy;
132 distort[4]=affine_matrix->tx;
133 distort[5]=affine_matrix->ty;
134 deskew_image=DistortImage(image,AffineProjectionDistortion,6,distort,
135 MagickTrue,exception);
136 return(deskew_image);
140 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
144 + C r o p T o F i t I m a g e %
148 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
150 % CropToFitImage() crops the sheared image as determined by the bounding box
151 % as defined by width and height and shearing angles.
153 % The format of the CropToFitImage method is:
155 % MagickBooleanType CropToFitImage(Image **image,
156 % const MagickRealType x_shear,const MagickRealType x_shear,
157 % const MagickRealType width,const MagickRealType height,
158 % const MagickBooleanType rotate,ExceptionInfo *exception)
160 % A description of each parameter follows.
162 % o image: the image.
164 % o x_shear, y_shear, width, height: Defines a region of the image to crop.
166 % o exception: return any errors or warnings in this structure.
169 static MagickBooleanType CropToFitImage(Image **image,
170 const MagickRealType x_shear,const MagickRealType y_shear,
171 const MagickRealType width,const MagickRealType height,
172 const MagickBooleanType rotate,ExceptionInfo *exception)
190 Calculate the rotated image size.
192 extent[0].x=(double) (-width/2.0);
193 extent[0].y=(double) (-height/2.0);
194 extent[1].x=(double) width/2.0;
195 extent[1].y=(double) (-height/2.0);
196 extent[2].x=(double) (-width/2.0);
197 extent[2].y=(double) height/2.0;
198 extent[3].x=(double) width/2.0;
199 extent[3].y=(double) height/2.0;
200 for (i=0; i < 4; i++)
202 extent[i].x+=x_shear*extent[i].y;
203 extent[i].y+=y_shear*extent[i].x;
204 if (rotate != MagickFalse)
205 extent[i].x+=x_shear*extent[i].y;
206 extent[i].x+=(double) (*image)->columns/2.0;
207 extent[i].y+=(double) (*image)->rows/2.0;
211 for (i=1; i < 4; i++)
213 if (min.x > extent[i].x)
215 if (min.y > extent[i].y)
217 if (max.x < extent[i].x)
219 if (max.y < extent[i].y)
222 geometry.x=(ssize_t) ceil(min.x-0.5);
223 geometry.y=(ssize_t) ceil(min.y-0.5);
224 geometry.width=(size_t) floor(max.x-min.x+0.5);
225 geometry.height=(size_t) floor(max.y-min.y+0.5);
227 (void) ParseAbsoluteGeometry("0x0+0+0",&(*image)->page);
228 crop_image=CropImage(*image,&geometry,exception);
229 if (crop_image == (Image *) NULL)
231 crop_image->page=page;
232 *image=DestroyImage(*image);
238 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
242 % D e s k e w I m a g e %
246 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
248 % DeskewImage() removes skew from the image. Skew is an artifact that
249 % occurs in scanned images because of the camera being misaligned,
250 % imperfections in the scanning or surface, or simply because the paper was
251 % not placed completely flat when scanned.
253 % The format of the DeskewImage method is:
255 % Image *DeskewImage(const Image *image,const double threshold,
256 % ExceptionInfo *exception)
258 % A description of each parameter follows:
260 % o image: the image.
262 % o threshold: separate background from foreground.
264 % o exception: return any errors or warnings in this structure.
268 typedef struct _RadonInfo
293 static RadonInfo *DestroyRadonInfo(RadonInfo *radon_info)
295 assert(radon_info != (RadonInfo *) NULL);
296 switch (radon_info->type)
300 if (radon_info->mapped == MagickFalse)
301 radon_info->cells=(unsigned short *) RelinquishMagickMemory(
304 radon_info->cells=(unsigned short *) UnmapBlob(radon_info->cells,
305 (size_t) radon_info->length);
306 RelinquishMagickResource(MemoryResource,radon_info->length);
311 radon_info->cells=(unsigned short *) UnmapBlob(radon_info->cells,(size_t)
313 RelinquishMagickResource(MapResource,radon_info->length);
317 if (radon_info->file != -1)
318 (void) close(radon_info->file);
319 (void) RelinquishUniqueFileResource(radon_info->path);
320 RelinquishMagickResource(DiskResource,radon_info->length);
326 return((RadonInfo *) RelinquishMagickMemory(radon_info));
329 static MagickBooleanType ResetRadonCells(RadonInfo *radon_info)
341 if (radon_info->type != DiskCache)
343 (void) ResetMagickMemory(radon_info->cells,0,(size_t) radon_info->length);
347 (void) lseek(radon_info->file,0,SEEK_SET);
348 for (y=0; y < (ssize_t) radon_info->height; y++)
350 for (x=0; x < (ssize_t) radon_info->width; x++)
352 count=write(radon_info->file,&value,sizeof(*radon_info->cells));
353 if (count != (ssize_t) sizeof(*radon_info->cells))
356 if (x < (ssize_t) radon_info->width)
359 return(y < (ssize_t) radon_info->height ? MagickFalse : MagickTrue);
362 static RadonInfo *AcquireRadonInfo(const Image *image,const size_t width,
363 const size_t height,ExceptionInfo *exception)
371 radon_info=(RadonInfo *) AcquireMagickMemory(sizeof(*radon_info));
372 if (radon_info == (RadonInfo *) NULL)
373 return((RadonInfo *) NULL);
374 (void) ResetMagickMemory(radon_info,0,sizeof(*radon_info));
375 radon_info->width=width;
376 radon_info->height=height;
377 radon_info->length=(MagickSizeType) width*height*sizeof(*radon_info->cells);
378 radon_info->type=MemoryCache;
379 status=AcquireMagickResource(AreaResource,radon_info->length);
380 if ((status != MagickFalse) &&
381 (radon_info->length == (MagickSizeType) ((size_t) radon_info->length)))
383 status=AcquireMagickResource(MemoryResource,radon_info->length);
384 if (status != MagickFalse)
386 radon_info->mapped=MagickFalse;
387 radon_info->cells=(unsigned short *) AcquireMagickMemory((size_t)
389 if (radon_info->cells == (unsigned short *) NULL)
391 radon_info->mapped=MagickTrue;
392 radon_info->cells=(unsigned short *) MapBlob(-1,IOMode,0,(size_t)
395 if (radon_info->cells == (unsigned short *) NULL)
396 RelinquishMagickResource(MemoryResource,radon_info->length);
399 radon_info->file=(-1);
400 if (radon_info->cells == (unsigned short *) NULL)
402 status=AcquireMagickResource(DiskResource,radon_info->length);
403 if (status == MagickFalse)
405 (void) ThrowMagickException(exception,GetMagickModule(),CacheError,
406 "CacheResourcesExhausted","`%s'",image->filename);
407 return(DestroyRadonInfo(radon_info));
409 radon_info->type=DiskCache;
410 (void) AcquireMagickResource(MemoryResource,radon_info->length);
411 radon_info->file=AcquireUniqueFileResource(radon_info->path);
412 if (radon_info->file == -1)
413 return(DestroyRadonInfo(radon_info));
414 status=AcquireMagickResource(MapResource,radon_info->length);
415 if (status != MagickFalse)
417 status=ResetRadonCells(radon_info);
418 if (status != MagickFalse)
420 radon_info->cells=(unsigned short *) MapBlob(radon_info->file,
421 IOMode,0,(size_t) radon_info->length);
422 if (radon_info->cells != (unsigned short *) NULL)
423 radon_info->type=MapCache;
425 RelinquishMagickResource(MapResource,radon_info->length);
432 static inline size_t MagickMin(const size_t x,const size_t y)
439 static inline ssize_t ReadRadonCell(const RadonInfo *radon_info,
440 const MagickOffsetType offset,const size_t length,unsigned char *buffer)
448 #if !defined(MAGICKCORE_HAVE_PPREAD)
449 #if defined(MAGICKCORE_OPENMP_SUPPORT)
450 #pragma omp critical (MagickCore_ReadRadonCell)
454 if (lseek(radon_info->file,offset,SEEK_SET) >= 0)
458 for (i=0; i < (ssize_t) length; i+=count)
460 #if !defined(MAGICKCORE_HAVE_PPREAD)
461 count=read(radon_info->file,buffer+i,MagickMin(length-i,(size_t)
464 count=pread(radon_info->file,buffer+i,MagickMin(length-i,(size_t)
465 SSIZE_MAX),offset+i);
476 #if !defined(MAGICKCORE_HAVE_PPREAD)
483 static inline ssize_t WriteRadonCell(const RadonInfo *radon_info,
484 const MagickOffsetType offset,const size_t length,const unsigned char *buffer)
492 #if !defined(MAGICKCORE_HAVE_PWRITE)
493 #if defined(MAGICKCORE_OPENMP_SUPPORT)
494 #pragma omp critical (MagickCore_WriteRadonCell)
497 if (lseek(radon_info->file,offset,SEEK_SET) >= 0)
501 for (i=0; i < (ssize_t) length; i+=count)
503 #if !defined(MAGICKCORE_HAVE_PWRITE)
504 count=write(radon_info->file,buffer+i,MagickMin(length-i,(size_t)
507 count=pwrite(radon_info->file,buffer+i,MagickMin(length-i,(size_t)
508 SSIZE_MAX),offset+i);
519 #if !defined(MAGICKCORE_HAVE_PWRITE)
526 static inline unsigned short GetRadonCell(const RadonInfo *radon_info,
527 const ssize_t x,const ssize_t y)
535 i=(MagickOffsetType) radon_info->height*x+y;
537 ((MagickSizeType) (i*sizeof(*radon_info->cells)) >= radon_info->length))
539 if (radon_info->type != DiskCache)
540 return(radon_info->cells[i]);
542 (void) ReadRadonCell(radon_info,i*sizeof(*radon_info->cells),
543 sizeof(*radon_info->cells),(unsigned char *) &value);
547 static inline MagickBooleanType SetRadonCell(const RadonInfo *radon_info,
548 const ssize_t x,const ssize_t y,const unsigned short value)
556 i=(MagickOffsetType) radon_info->height*x+y;
558 ((MagickSizeType) (i*sizeof(*radon_info->cells)) >= radon_info->length))
560 if (radon_info->type != DiskCache)
562 radon_info->cells[i]=value;
565 count=WriteRadonCell(radon_info,i*sizeof(*radon_info->cells),
566 sizeof(*radon_info->cells),(const unsigned char *) &value);
567 if (count != (ssize_t) sizeof(*radon_info->cells))
572 static void RadonProjection(RadonInfo *source_cells,
573 RadonInfo *destination_cells,const ssize_t sign,size_t *projection)
590 for (step=1; step < p->width; step*=2)
592 for (x=0; x < (ssize_t) p->width; x+=2*(ssize_t) step)
603 for (i=0; i < (ssize_t) step; i++)
605 for (y=0; y < (ssize_t) (p->height-i-1); y++)
607 cell=GetRadonCell(p,x+i,y);
608 (void) SetRadonCell(q,x+2*i,y,cell+GetRadonCell(p,x+i+(ssize_t)
610 (void) SetRadonCell(q,x+2*i+1,y,cell+GetRadonCell(p,x+i+(ssize_t)
613 for ( ; y < (ssize_t) (p->height-i); y++)
615 cell=GetRadonCell(p,x+i,y);
616 (void) SetRadonCell(q,x+2*i,y,cell+GetRadonCell(p,x+i+(ssize_t) step,
618 (void) SetRadonCell(q,x+2*i+1,y,cell);
620 for ( ; y < (ssize_t) p->height; y++)
622 cell=GetRadonCell(p,x+i,y);
623 (void) SetRadonCell(q,x+2*i,y,cell);
624 (void) SetRadonCell(q,x+2*i+1,y,cell);
632 #if defined(MAGICKCORE_OPENMP_SUPPORT)
633 #pragma omp parallel for schedule(dynamic,4)
635 for (x=0; x < (ssize_t) p->width; x++)
644 for (y=0; y < (ssize_t) (p->height-1); y++)
649 delta=GetRadonCell(p,x,y)-(ssize_t) GetRadonCell(p,x,y+1);
652 projection[p->width+sign*x-1]=sum;
656 static MagickBooleanType RadonTransform(const Image *image,
657 const double threshold,size_t *projection,ExceptionInfo *exception)
685 for (width=1; width < ((image->columns+7)/8); width<<=1) ;
686 source_cells=AcquireRadonInfo(image,width,image->rows,exception);
687 destination_cells=AcquireRadonInfo(image,width,image->rows,exception);
688 if ((source_cells == (RadonInfo *) NULL) ||
689 (destination_cells == (RadonInfo *) NULL))
691 if (destination_cells != (RadonInfo *) NULL)
692 destination_cells=DestroyRadonInfo(destination_cells);
693 if (source_cells != (RadonInfo *) NULL)
694 source_cells=DestroyRadonInfo(source_cells);
697 if (ResetRadonCells(source_cells) == MagickFalse)
699 destination_cells=DestroyRadonInfo(destination_cells);
700 source_cells=DestroyRadonInfo(source_cells);
703 for (i=0; i < 256; i++)
705 byte=(unsigned char) i;
706 for (count=0; byte != 0; byte>>=1)
708 bits[i]=(unsigned short) count;
711 image_view=AcquireCacheView(image);
712 #if defined(MAGICKCORE_OPENMP_SUPPORT)
713 #pragma omp parallel for schedule(dynamic,4) shared(status)
715 for (y=0; y < (ssize_t) image->rows; y++)
717 register const Quantum
728 if (status == MagickFalse)
730 p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
731 if (p == (const Quantum *) NULL)
738 i=(ssize_t) (image->columns+7)/8;
739 for (x=0; x < (ssize_t) image->columns; x++)
742 if (GetPixelIntensity(image,p) < threshold)
747 (void) SetRadonCell(source_cells,--i,y,bits[byte]);
751 p+=GetPixelChannels(image);
756 (void) SetRadonCell(source_cells,--i,y,bits[byte]);
759 RadonProjection(source_cells,destination_cells,-1,projection);
760 (void) ResetRadonCells(source_cells);
761 #if defined(MAGICKCORE_OPENMP_SUPPORT)
762 #pragma omp parallel for schedule(dynamic,4) shared(status)
764 for (y=0; y < (ssize_t) image->rows; y++)
766 register const Quantum
777 if (status == MagickFalse)
779 p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
780 if (p == (const Quantum *) NULL)
788 for (x=0; x < (ssize_t) image->columns; x++)
791 if (GetPixelIntensity(image,p) < threshold)
796 (void) SetRadonCell(source_cells,i++,y,bits[byte]);
800 p+=GetPixelChannels(image);
805 (void) SetRadonCell(source_cells,i++,y,bits[byte]);
808 RadonProjection(source_cells,destination_cells,1,projection);
809 image_view=DestroyCacheView(image_view);
810 destination_cells=DestroyRadonInfo(destination_cells);
811 source_cells=DestroyRadonInfo(source_cells);
815 static void GetImageBackgroundColor(Image *image,const ssize_t offset,
816 ExceptionInfo *exception)
831 Compute average background color.
835 GetPixelInfo(image,&background);
837 image_view=AcquireCacheView(image);
838 for (y=0; y < (ssize_t) image->rows; y++)
840 register const Quantum
846 if ((y >= offset) && (y < ((ssize_t) image->rows-offset)))
848 p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
849 if (p == (const Quantum *) NULL)
851 for (x=0; x < (ssize_t) image->columns; x++)
853 if ((x >= offset) && (x < ((ssize_t) image->columns-offset)))
855 background.red+=QuantumScale*GetPixelRed(image,p);
856 background.green+=QuantumScale*GetPixelGreen(image,p);
857 background.blue+=QuantumScale*GetPixelBlue(image,p);
858 if ((GetPixelAlphaTraits(image) & UpdatePixelTrait) != 0)
859 background.alpha+=QuantumScale*GetPixelAlpha(image,p);
861 p+=GetPixelChannels(image);
864 image_view=DestroyCacheView(image_view);
865 image->background_color.red=ClampToQuantum((MagickRealType) QuantumRange*
866 background.red/count);
867 image->background_color.green=ClampToQuantum((MagickRealType) QuantumRange*
868 background.green/count);
869 image->background_color.blue=ClampToQuantum((MagickRealType) QuantumRange*
870 background.blue/count);
871 if ((GetPixelAlphaTraits(image) & UpdatePixelTrait) != 0)
872 image->background_color.alpha=ClampToQuantum((MagickRealType) QuantumRange*
873 background.alpha/count);
876 MagickExport Image *DeskewImage(const Image *image,const double threshold,
877 ExceptionInfo *exception)
912 Compute deskew angle.
914 for (width=1; width < ((image->columns+7)/8); width<<=1) ;
915 projection=(size_t *) AcquireQuantumMemory((size_t) (2*width-1),
916 sizeof(*projection));
917 if (projection == (size_t *) NULL)
918 ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
919 status=RadonTransform(image,threshold,projection,exception);
920 if (status == MagickFalse)
922 projection=(size_t *) RelinquishMagickMemory(projection);
923 ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
927 for (i=0; i < (ssize_t) (2*width-1); i++)
929 if (projection[i] > max_projection)
931 skew=i-(ssize_t) width+1;
932 max_projection=projection[i];
935 projection=(size_t *) RelinquishMagickMemory(projection);
939 clone_image=CloneImage(image,0,0,MagickTrue,exception);
940 if (clone_image == (Image *) NULL)
941 return((Image *) NULL);
942 (void) SetImageVirtualPixelMethod(clone_image,BackgroundVirtualPixelMethod);
943 degrees=RadiansToDegrees(-atan((double) skew/width/8));
944 if (image->debug != MagickFalse)
945 (void) LogMagickEvent(TransformEvent,GetMagickModule(),
946 " Deskew angle: %g",degrees);
947 affine_matrix.sx=cos(DegreesToRadians(fmod((double) degrees,360.0)));
948 affine_matrix.rx=sin(DegreesToRadians(fmod((double) degrees,360.0)));
949 affine_matrix.ry=(-sin(DegreesToRadians(fmod((double) degrees,360.0))));
950 affine_matrix.sy=cos(DegreesToRadians(fmod((double) degrees,360.0)));
951 affine_matrix.tx=0.0;
952 affine_matrix.ty=0.0;
953 artifact=GetImageArtifact(image,"deskew:auto-crop");
954 if (artifact == (const char *) NULL)
956 deskew_image=AffineTransformImage(clone_image,&affine_matrix,exception);
957 clone_image=DestroyImage(clone_image);
958 return(deskew_image);
963 GetImageBackgroundColor(clone_image,(ssize_t) StringToLong(artifact),
965 deskew_image=AffineTransformImage(clone_image,&affine_matrix,exception);
966 clone_image=DestroyImage(clone_image);
967 if (deskew_image == (Image *) NULL)
968 return((Image *) NULL);
969 median_image=StatisticImage(deskew_image,MedianStatistic,3,3,exception);
970 if (median_image == (Image *) NULL)
972 deskew_image=DestroyImage(deskew_image);
973 return((Image *) NULL);
975 geometry=GetImageBoundingBox(median_image,exception);
976 median_image=DestroyImage(median_image);
977 if (image->debug != MagickFalse)
978 (void) LogMagickEvent(TransformEvent,GetMagickModule()," Deskew geometry: "
979 "%.20gx%.20g%+.20g%+.20g",(double) geometry.width,(double)
980 geometry.height,(double) geometry.x,(double) geometry.y);
981 crop_image=CropImage(deskew_image,&geometry,exception);
982 deskew_image=DestroyImage(deskew_image);
987 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
991 + I n t e g r a l R o t a t e I m a g e %
995 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
997 % IntegralRotateImage() rotates the image an integral of 90 degrees. It
998 % allocates the memory necessary for the new Image structure and returns a
999 % pointer to the rotated image.
1001 % The format of the IntegralRotateImage method is:
1003 % Image *IntegralRotateImage(const Image *image,size_t rotations,
1004 % ExceptionInfo *exception)
1006 % A description of each parameter follows.
1008 % o image: the image.
1010 % o rotations: Specifies the number of 90 degree rotations.
1013 static Image *IntegralRotateImage(const Image *image,size_t rotations,
1014 ExceptionInfo *exception)
1016 #define RotateImageTag "Rotate/Image"
1038 Initialize rotated image attributes.
1040 assert(image != (Image *) NULL);
1044 return(CloneImage(image,0,0,MagickTrue,exception));
1045 if ((rotations == 1) || (rotations == 3))
1046 rotate_image=CloneImage(image,image->rows,image->columns,MagickTrue,
1049 rotate_image=CloneImage(image,image->columns,image->rows,MagickTrue,
1051 if (rotate_image == (Image *) NULL)
1052 return((Image *) NULL);
1054 Integral rotate the image.
1058 image_view=AcquireCacheView(image);
1059 rotate_view=AcquireCacheView(rotate_image);
1081 GetPixelCacheTileSize(image,&tile_width,&tile_height);
1083 for ( ; tile_y < (ssize_t) image->rows; tile_y+=(ssize_t) tile_height)
1088 if (status == MagickFalse)
1091 for ( ; tile_x < (ssize_t) image->columns; tile_x+=(ssize_t) tile_width)
1096 register const Quantum
1110 if ((tile_x+(ssize_t) tile_width) > (ssize_t) image->columns)
1111 width=(size_t) (tile_width-(tile_x+tile_width-image->columns));
1113 if ((tile_y+(ssize_t) tile_height) > (ssize_t) image->rows)
1114 height=(size_t) (tile_height-(tile_y+tile_height-image->rows));
1115 p=GetCacheViewVirtualPixels(image_view,tile_x,tile_y,width,height,
1117 if (p == (const Quantum *) NULL)
1122 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1123 #pragma omp parallel for schedule(static,1) shared(progress, status)
1125 for (y=0; y < (ssize_t) width; y++)
1127 register const Quantum
1128 *restrict tile_pixels;
1133 if (status == MagickFalse)
1135 q=QueueCacheViewAuthenticPixels(rotate_view,(ssize_t)
1136 (rotate_image->columns-(tile_y+height)),y+tile_x,height,1,
1138 if (q == (Quantum *) NULL)
1143 tile_pixels=p+((height-1)*width+y)*GetPixelChannels(image);
1144 for (x=0; x < (ssize_t) height; x++)
1149 for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
1158 traits=GetPixelChannelMapTraits(image,(PixelChannel) i);
1159 channel=GetPixelChannelMapChannel(image,(PixelChannel) i);
1160 rotate_traits=GetPixelChannelMapTraits(rotate_image,channel);
1161 if ((traits == UndefinedPixelTrait) ||
1162 (rotate_traits == UndefinedPixelTrait))
1164 if ((rotate_traits & CopyPixelTrait) != 0)
1166 q[channel]=tile_pixels[i];
1169 q[channel]=tile_pixels[i];
1171 tile_pixels-=width*GetPixelChannels(image);
1172 q+=GetPixelChannels(rotate_image);
1174 sync=SyncCacheViewAuthenticPixels(rotate_view,exception);
1175 if (sync == MagickFalse)
1179 if (image->progress_monitor != (MagickProgressMonitor) NULL)
1184 proceed=SetImageProgress(image,RotateImageTag,progress+=tile_height,
1186 if (proceed == MagickFalse)
1190 (void) SetImageProgress(image,RotateImageTag,(MagickOffsetType)
1191 image->rows-1,image->rows);
1192 Swap(page.width,page.height);
1193 Swap(page.x,page.y);
1194 if (page.width != 0)
1195 page.x=(ssize_t) (page.width-rotate_image->columns-page.x);
1203 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1204 #pragma omp parallel for schedule(static,8) shared(progress,status)
1206 for (y=0; y < (ssize_t) image->rows; y++)
1211 register const Quantum
1220 if (status == MagickFalse)
1222 p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
1223 q=QueueCacheViewAuthenticPixels(rotate_view,0,(ssize_t) (image->rows-y-
1224 1),image->columns,1,exception);
1225 if ((p == (const Quantum *) NULL) || (q == (Quantum *) NULL))
1230 q+=GetPixelChannels(rotate_image)*image->columns;
1231 for (x=0; x < (ssize_t) image->columns; x++)
1236 q-=GetPixelChannels(rotate_image);
1237 for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
1246 traits=GetPixelChannelMapTraits(image,(PixelChannel) i);
1247 channel=GetPixelChannelMapChannel(image,(PixelChannel) i);
1248 rotate_traits=GetPixelChannelMapTraits(rotate_image,channel);
1249 if ((traits == UndefinedPixelTrait) ||
1250 (rotate_traits == UndefinedPixelTrait))
1252 if ((rotate_traits & CopyPixelTrait) != 0)
1259 p+=GetPixelChannels(image);
1261 sync=SyncCacheViewAuthenticPixels(rotate_view,exception);
1262 if (sync == MagickFalse)
1264 if (image->progress_monitor != (MagickProgressMonitor) NULL)
1269 proceed=SetImageProgress(image,RotateImageTag,progress++,
1271 if (proceed == MagickFalse)
1275 if (page.width != 0)
1276 page.x=(ssize_t) (page.width-rotate_image->columns-page.x);
1277 if (page.height != 0)
1278 page.y=(ssize_t) (page.height-rotate_image->rows-page.y);
1293 GetPixelCacheTileSize(image,&tile_width,&tile_height);
1295 for ( ; tile_y < (ssize_t) image->rows; tile_y+=(ssize_t) tile_height)
1300 if (status == MagickFalse)
1303 for ( ; tile_x < (ssize_t) image->columns; tile_x+=(ssize_t) tile_width)
1308 register const Quantum
1322 if ((tile_x+(ssize_t) tile_width) > (ssize_t) image->columns)
1323 width=(size_t) (tile_width-(tile_x+tile_width-image->columns));
1325 if ((tile_y+(ssize_t) tile_height) > (ssize_t) image->rows)
1326 height=(size_t) (tile_height-(tile_y+tile_height-image->rows));
1327 p=GetCacheViewVirtualPixels(image_view,tile_x,tile_y,width,height,
1329 if (p == (const Quantum *) NULL)
1334 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1335 #pragma omp parallel for schedule(static,1) shared(progress,status)
1337 for (y=0; y < (ssize_t) width; y++)
1339 register const Quantum
1340 *restrict tile_pixels;
1345 if (status == MagickFalse)
1347 q=QueueCacheViewAuthenticPixels(rotate_view,tile_y,(ssize_t) (y+
1348 rotate_image->rows-(tile_x+width)),height,1,exception);
1349 if (q == (Quantum *) NULL)
1354 tile_pixels=p+((width-1)-y)*GetPixelChannels(image);
1355 for (x=0; x < (ssize_t) height; x++)
1360 for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
1369 traits=GetPixelChannelMapTraits(image,(PixelChannel) i);
1370 channel=GetPixelChannelMapChannel(image,(PixelChannel) i);
1371 rotate_traits=GetPixelChannelMapTraits(rotate_image,channel);
1372 if ((traits == UndefinedPixelTrait) ||
1373 (rotate_traits == UndefinedPixelTrait))
1375 if ((rotate_traits & CopyPixelTrait) != 0)
1377 q[channel]=tile_pixels[i];
1380 q[channel]=tile_pixels[i];
1382 tile_pixels+=width*GetPixelChannels(image);
1383 q+=GetPixelChannels(rotate_image);
1385 sync=SyncCacheViewAuthenticPixels(rotate_view,exception);
1386 if (sync == MagickFalse)
1390 if (image->progress_monitor != (MagickProgressMonitor) NULL)
1395 proceed=SetImageProgress(image,RotateImageTag,progress+=tile_height,
1397 if (proceed == MagickFalse)
1401 (void) SetImageProgress(image,RotateImageTag,(MagickOffsetType)
1402 image->rows-1,image->rows);
1403 Swap(page.width,page.height);
1404 Swap(page.x,page.y);
1405 if (page.height != 0)
1406 page.y=(ssize_t) (page.height-rotate_image->rows-page.y);
1410 rotate_view=DestroyCacheView(rotate_view);
1411 image_view=DestroyCacheView(image_view);
1412 rotate_image->type=image->type;
1413 rotate_image->page=page;
1414 if (status == MagickFalse)
1415 rotate_image=DestroyImage(rotate_image);
1416 return(rotate_image);
1420 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1424 + X S h e a r I m a g e %
1428 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1430 % XShearImage() shears the image in the X direction with a shear angle of
1431 % 'degrees'. Positive angles shear counter-clockwise (right-hand rule), and
1432 % negative angles shear clockwise. Angles are measured relative to a vertical
1433 % Y-axis. X shears will widen an image creating 'empty' triangles on the left
1434 % and right sides of the source image.
1436 % The format of the XShearImage method is:
1438 % MagickBooleanType XShearImage(Image *image,const MagickRealType degrees,
1439 % const size_t width,const size_t height,
1440 % const ssize_t x_offset,const ssize_t y_offset,ExceptionInfo *exception)
1442 % A description of each parameter follows.
1444 % o image: the image.
1446 % o degrees: A MagickRealType representing the shearing angle along the X
1449 % o width, height, x_offset, y_offset: Defines a region of the image
1452 % o exception: return any errors or warnings in this structure.
1455 static MagickBooleanType XShearImage(Image *image,const MagickRealType degrees,
1456 const size_t width,const size_t height,const ssize_t x_offset,
1457 const ssize_t y_offset,ExceptionInfo *exception)
1459 #define XShearImageTag "XShear/Image"
1482 assert(image != (Image *) NULL);
1483 assert(image->signature == MagickSignature);
1484 if (image->debug != MagickFalse)
1485 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1486 GetPixelInfo(image,&background);
1487 SetPixelInfoPacket(image,&image->background_color,&background);
1488 if (image->colorspace == CMYKColorspace)
1489 ConvertRGBToCMYK(&background);
1495 image_view=AcquireCacheView(image);
1496 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1497 #pragma omp parallel for schedule(dynamic,4) shared(progress, status)
1499 for (y=0; y < (ssize_t) height; y++)
1523 if (status == MagickFalse)
1525 p=GetCacheViewAuthenticPixels(image_view,0,y_offset+y,image->columns,1,
1527 if (p == (Quantum *) NULL)
1532 p+=x_offset*GetPixelChannels(image);
1533 displacement=degrees*(MagickRealType) (y-height/2.0);
1534 if (displacement == 0.0)
1536 if (displacement > 0.0)
1540 displacement*=(-1.0);
1543 step=(ssize_t) floor((double) displacement);
1544 area=(MagickRealType) (displacement-step);
1547 GetPixelInfo(image,&source);
1548 GetPixelInfo(image,&destination);
1554 Transfer pixels left-to-right.
1556 if (step > x_offset)
1558 q=p-step*GetPixelChannels(image);
1559 for (i=0; i < (ssize_t) width; i++)
1561 if ((x_offset+i) < step)
1563 p+=GetPixelChannels(image);
1564 SetPixelInfo(image,p,&pixel);
1565 q+=GetPixelChannels(image);
1568 SetPixelInfo(image,p,&source);
1569 CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
1570 &source,(MagickRealType) GetPixelAlpha(image,p),area,
1572 SetPixelPixelInfo(image,&destination,q);
1573 SetPixelInfo(image,p,&pixel);
1574 p+=GetPixelChannels(image);
1575 q+=GetPixelChannels(image);
1577 CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
1578 &background,(MagickRealType) background.alpha,area,&destination);
1579 SetPixelPixelInfo(image,&destination,q);
1580 q+=GetPixelChannels(image);
1581 for (i=0; i < (step-1); i++)
1583 SetPixelPixelInfo(image,&background,q);
1584 q+=GetPixelChannels(image);
1591 Transfer pixels right-to-left.
1593 p+=width*GetPixelChannels(image);
1594 q=p+step*GetPixelChannels(image);
1595 for (i=0; i < (ssize_t) width; i++)
1597 p-=GetPixelChannels(image);
1598 q-=GetPixelChannels(image);
1599 if ((size_t) (x_offset+width+step-i) >= image->columns)
1601 SetPixelInfo(image,p,&source);
1602 CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
1603 &source,(MagickRealType) GetPixelAlpha(image,p),area,
1605 SetPixelPixelInfo(image,&destination,q);
1606 SetPixelInfo(image,p,&pixel);
1608 CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
1609 &background,(MagickRealType) background.alpha,area,&destination);
1610 q-=GetPixelChannels(image);
1611 SetPixelPixelInfo(image,&destination,q);
1612 for (i=0; i < (step-1); i++)
1614 q-=GetPixelChannels(image);
1615 SetPixelPixelInfo(image,&background,q);
1620 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1622 if (image->progress_monitor != (MagickProgressMonitor) NULL)
1627 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1628 #pragma omp critical (MagickCore_XShearImage)
1630 proceed=SetImageProgress(image,XShearImageTag,progress++,height);
1631 if (proceed == MagickFalse)
1635 image_view=DestroyCacheView(image_view);
1640 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1644 + Y S h e a r I m a g e %
1648 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1650 % YShearImage shears the image in the Y direction with a shear angle of
1651 % 'degrees'. Positive angles shear counter-clockwise (right-hand rule), and
1652 % negative angles shear clockwise. Angles are measured relative to a
1653 % horizontal X-axis. Y shears will increase the height of an image creating
1654 % 'empty' triangles on the top and bottom of the source image.
1656 % The format of the YShearImage method is:
1658 % MagickBooleanType YShearImage(Image *image,const MagickRealType degrees,
1659 % const size_t width,const size_t height,
1660 % const ssize_t x_offset,const ssize_t y_offset,ExceptionInfo *exception)
1662 % A description of each parameter follows.
1664 % o image: the image.
1666 % o degrees: A MagickRealType representing the shearing angle along the Y
1669 % o width, height, x_offset, y_offset: Defines a region of the image
1672 % o exception: return any errors or warnings in this structure.
1675 static MagickBooleanType YShearImage(Image *image,const MagickRealType degrees,
1676 const size_t width,const size_t height,const ssize_t x_offset,
1677 const ssize_t y_offset,ExceptionInfo *exception)
1679 #define YShearImageTag "YShear/Image"
1702 assert(image != (Image *) NULL);
1703 assert(image->signature == MagickSignature);
1704 if (image->debug != MagickFalse)
1705 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1706 GetPixelInfo(image,&background);
1707 SetPixelInfoPacket(image,&image->background_color,&background);
1708 if (image->colorspace == CMYKColorspace)
1709 ConvertRGBToCMYK(&background);
1715 image_view=AcquireCacheView(image);
1716 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1717 #pragma omp parallel for schedule(dynamic,4) shared(progress, status)
1719 for (x=0; x < (ssize_t) width; x++)
1743 if (status == MagickFalse)
1745 p=GetCacheViewAuthenticPixels(image_view,x_offset+x,0,1,image->rows,
1747 if (p == (Quantum *) NULL)
1752 p+=y_offset*GetPixelChannels(image);
1753 displacement=degrees*(MagickRealType) (x-width/2.0);
1754 if (displacement == 0.0)
1756 if (displacement > 0.0)
1760 displacement*=(-1.0);
1763 step=(ssize_t) floor((double) displacement);
1764 area=(MagickRealType) (displacement-step);
1767 GetPixelInfo(image,&source);
1768 GetPixelInfo(image,&destination);
1774 Transfer pixels top-to-bottom.
1776 if (step > y_offset)
1778 q=p-step*GetPixelChannels(image);
1779 for (i=0; i < (ssize_t) height; i++)
1781 if ((y_offset+i) < step)
1783 p+=GetPixelChannels(image);
1784 SetPixelInfo(image,p,&pixel);
1785 q+=GetPixelChannels(image);
1788 SetPixelInfo(image,p,&source);
1789 CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
1790 &source,(MagickRealType) GetPixelAlpha(image,p),area,
1792 SetPixelPixelInfo(image,&destination,q);
1793 SetPixelInfo(image,p,&pixel);
1794 p+=GetPixelChannels(image);
1795 q+=GetPixelChannels(image);
1797 CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
1798 &background,(MagickRealType) background.alpha,area,&destination);
1799 SetPixelPixelInfo(image,&destination,q);
1800 q+=GetPixelChannels(image);
1801 for (i=0; i < (step-1); i++)
1803 SetPixelPixelInfo(image,&background,q);
1804 q+=GetPixelChannels(image);
1811 Transfer pixels bottom-to-top.
1813 p+=height*GetPixelChannels(image);
1814 q=p+step*GetPixelChannels(image);
1815 for (i=0; i < (ssize_t) height; i++)
1817 p-=GetPixelChannels(image);
1818 q-=GetPixelChannels(image);
1819 if ((size_t) (y_offset+height+step-i) >= image->rows)
1821 SetPixelInfo(image,p,&source);
1822 CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
1823 &source,(MagickRealType) GetPixelAlpha(image,p),area,
1825 SetPixelPixelInfo(image,&destination,q);
1826 SetPixelInfo(image,p,&pixel);
1828 CompositePixelInfoAreaBlend(&pixel,(MagickRealType) pixel.alpha,
1829 &background,(MagickRealType) background.alpha,area,&destination);
1830 q-=GetPixelChannels(image);
1831 SetPixelPixelInfo(image,&destination,q);
1832 for (i=0; i < (step-1); i++)
1834 q-=GetPixelChannels(image);
1835 SetPixelPixelInfo(image,&background,q);
1840 if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
1842 if (image->progress_monitor != (MagickProgressMonitor) NULL)
1847 #if defined(MAGICKCORE_OPENMP_SUPPORT)
1848 #pragma omp critical (MagickCore_YShearImage)
1850 proceed=SetImageProgress(image,YShearImageTag,progress++,image->rows);
1851 if (proceed == MagickFalse)
1855 image_view=DestroyCacheView(image_view);
1860 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1864 % R o t a t e I m a g e %
1868 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
1870 % RotateImage() creates a new image that is a rotated copy of an existing
1871 % one. Positive angles rotate counter-clockwise (right-hand rule), while
1872 % negative angles rotate clockwise. Rotated images are usually larger than
1873 % the originals and have 'empty' triangular corners. X axis. Empty
1874 % triangles left over from shearing the image are filled with the background
1875 % color defined by member 'background_color' of the image. RotateImage
1876 % allocates the memory necessary for the new Image structure and returns a
1877 % pointer to the new image.
1879 % RotateImage() is based on the paper "A Fast Algorithm for General
1880 % Raster Rotatation" by Alan W. Paeth. RotateImage is adapted from a similar
1881 % method based on the Paeth paper written by Michael Halle of the Spatial
1882 % Imaging Group, MIT Media Lab.
1884 % The format of the RotateImage method is:
1886 % Image *RotateImage(const Image *image,const double degrees,
1887 % ExceptionInfo *exception)
1889 % A description of each parameter follows.
1891 % o image: the image.
1893 % o degrees: Specifies the number of degrees to rotate the image.
1895 % o exception: return any errors or warnings in this structure.
1898 MagickExport Image *RotateImage(const Image *image,const double degrees,
1899 ExceptionInfo *exception)
1928 Adjust rotation angle.
1930 assert(image != (Image *) NULL);
1931 assert(image->signature == MagickSignature);
1932 if (image->debug != MagickFalse)
1933 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
1934 assert(exception != (ExceptionInfo *) NULL);
1935 assert(exception->signature == MagickSignature);
1937 while (angle < -45.0)
1939 for (rotations=0; angle > 45.0; rotations++)
1943 Calculate shear equations.
1945 integral_image=IntegralRotateImage(image,rotations,exception);
1946 if (integral_image == (Image *) NULL)
1947 ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
1948 shear.x=(-tan((double) DegreesToRadians(angle)/2.0));
1949 shear.y=sin((double) DegreesToRadians(angle));
1950 if ((shear.x == 0.0) && (shear.y == 0.0))
1951 return(integral_image);
1952 if (SetImageStorageClass(integral_image,DirectClass,exception) == MagickFalse)
1954 integral_image=DestroyImage(integral_image);
1955 return(integral_image);
1957 if (integral_image->matte == MagickFalse)
1958 (void) SetImageAlphaChannel(integral_image,OpaqueAlphaChannel,exception);
1962 width=image->columns;
1964 if ((rotations == 1) || (rotations == 3))
1967 height=image->columns;
1969 y_width=width+(ssize_t) floor(fabs(shear.x)*height+0.5);
1970 x_offset=(ssize_t) ceil((double) width+((fabs(shear.y)*height)-width)/2.0-
1972 y_offset=(ssize_t) ceil((double) height+((fabs(shear.y)*y_width)-height)/2.0-
1975 Surround image with a border.
1977 integral_image->border_color=integral_image->background_color;
1978 integral_image->compose=CopyCompositeOp;
1979 border_info.width=(size_t) x_offset;
1980 border_info.height=(size_t) y_offset;
1981 rotate_image=BorderImage(integral_image,&border_info,image->compose,
1983 integral_image=DestroyImage(integral_image);
1984 if (rotate_image == (Image *) NULL)
1985 ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
1989 status=XShearImage(rotate_image,shear.x,width,height,x_offset,(ssize_t)
1990 (rotate_image->rows-height)/2,exception);
1991 if (status == MagickFalse)
1993 rotate_image=DestroyImage(rotate_image);
1994 return((Image *) NULL);
1996 status=YShearImage(rotate_image,shear.y,y_width,height,(ssize_t)
1997 (rotate_image->columns-y_width)/2,y_offset,exception);
1998 if (status == MagickFalse)
2000 rotate_image=DestroyImage(rotate_image);
2001 return((Image *) NULL);
2003 status=XShearImage(rotate_image,shear.x,y_width,rotate_image->rows,(ssize_t)
2004 (rotate_image->columns-y_width)/2,0,exception);
2005 if (status == MagickFalse)
2007 rotate_image=DestroyImage(rotate_image);
2008 return((Image *) NULL);
2010 status=CropToFitImage(&rotate_image,shear.x,shear.y,(MagickRealType) width,
2011 (MagickRealType) height,MagickTrue,exception);
2012 if (status == MagickFalse)
2014 rotate_image=DestroyImage(rotate_image);
2015 return((Image *) NULL);
2017 rotate_image->compose=image->compose;
2018 rotate_image->page.width=0;
2019 rotate_image->page.height=0;
2020 return(rotate_image);
2024 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2028 % S h e a r I m a g e %
2032 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2034 % ShearImage() creates a new image that is a shear_image copy of an existing
2035 % one. Shearing slides one edge of an image along the X or Y axis, creating
2036 % a parallelogram. An X direction shear slides an edge along the X axis,
2037 % while a Y direction shear slides an edge along the Y axis. The amount of
2038 % the shear is controlled by a shear angle. For X direction shears, x_shear
2039 % is measured relative to the Y axis, and similarly, for Y direction shears
2040 % y_shear is measured relative to the X axis. Empty triangles left over from
2041 % shearing the image are filled with the background color defined by member
2042 % 'background_color' of the image.. ShearImage() allocates the memory
2043 % necessary for the new Image structure and returns a pointer to the new image.
2045 % ShearImage() is based on the paper "A Fast Algorithm for General Raster
2046 % Rotatation" by Alan W. Paeth.
2048 % The format of the ShearImage method is:
2050 % Image *ShearImage(const Image *image,const double x_shear,
2051 % const double y_shear,ExceptionInfo *exception)
2053 % A description of each parameter follows.
2055 % o image: the image.
2057 % o x_shear, y_shear: Specifies the number of degrees to shear the image.
2059 % o exception: return any errors or warnings in this structure.
2062 MagickExport Image *ShearImage(const Image *image,const double x_shear,
2063 const double y_shear,ExceptionInfo *exception)
2085 assert(image != (Image *) NULL);
2086 assert(image->signature == MagickSignature);
2087 if (image->debug != MagickFalse)
2088 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
2089 assert(exception != (ExceptionInfo *) NULL);
2090 assert(exception->signature == MagickSignature);
2091 if ((x_shear != 0.0) && (fmod(x_shear,90.0) == 0.0))
2092 ThrowImageException(ImageError,"AngleIsDiscontinuous");
2093 if ((y_shear != 0.0) && (fmod(y_shear,90.0) == 0.0))
2094 ThrowImageException(ImageError,"AngleIsDiscontinuous");
2096 Initialize shear angle.
2098 integral_image=CloneImage(image,0,0,MagickTrue,exception);
2099 if (integral_image == (Image *) NULL)
2100 ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
2101 shear.x=(-tan(DegreesToRadians(fmod(x_shear,360.0))));
2102 shear.y=tan(DegreesToRadians(fmod(y_shear,360.0)));
2103 if ((shear.x == 0.0) && (shear.y == 0.0))
2104 return(integral_image);
2105 if (SetImageStorageClass(integral_image,DirectClass,exception) == MagickFalse)
2107 integral_image=DestroyImage(integral_image);
2108 return(integral_image);
2110 if (integral_image->matte == MagickFalse)
2111 (void) SetImageAlphaChannel(integral_image,OpaqueAlphaChannel,exception);
2115 y_width=image->columns+(ssize_t) floor(fabs(shear.x)*image->rows+0.5);
2116 x_offset=(ssize_t) ceil((double) image->columns+((fabs(shear.x)*image->rows)-
2117 image->columns)/2.0-0.5);
2118 y_offset=(ssize_t) ceil((double) image->rows+((fabs(shear.y)*y_width)-
2119 image->rows)/2.0-0.5);
2121 Surround image with border.
2123 integral_image->border_color=integral_image->background_color;
2124 integral_image->compose=CopyCompositeOp;
2125 border_info.width=(size_t) x_offset;
2126 border_info.height=(size_t) y_offset;
2127 shear_image=BorderImage(integral_image,&border_info,image->compose,exception);
2128 integral_image=DestroyImage(integral_image);
2129 if (shear_image == (Image *) NULL)
2130 ThrowImageException(ResourceLimitError,"MemoryAllocationFailed");
2134 if (shear_image->matte == MagickFalse)
2135 (void) SetImageAlphaChannel(shear_image,OpaqueAlphaChannel,exception);
2136 status=XShearImage(shear_image,shear.x,image->columns,image->rows,x_offset,
2137 (ssize_t) (shear_image->rows-image->rows)/2,exception);
2138 if (status == MagickFalse)
2140 shear_image=DestroyImage(shear_image);
2141 return((Image *) NULL);
2143 status=YShearImage(shear_image,shear.y,y_width,image->rows,(ssize_t)
2144 (shear_image->columns-y_width)/2,y_offset,exception);
2145 if (status == MagickFalse)
2147 shear_image=DestroyImage(shear_image);
2148 return((Image *) NULL);
2150 status=CropToFitImage(&shear_image,shear.x,shear.y,(MagickRealType)
2151 image->columns,(MagickRealType) image->rows,MagickFalse,exception);
2152 if (status == MagickFalse)
2154 shear_image=DestroyImage(shear_image);
2155 return((Image *) NULL);
2157 shear_image->compose=image->compose;
2158 shear_image->page.width=0;
2159 shear_image->page.height=0;
2160 return(shear_image);