cristy | 3ed852e | 2009-09-05 21:47:34 +0000 | [diff] [blame] | 1 | /* |
| 2 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 3 | % % |
| 4 | % % |
| 5 | % % |
| 6 | % RRRR EEEEE SSSSS AAA M M PPPP L EEEEE % |
| 7 | % R R E SS A A MM MM P P L E % |
| 8 | % RRRR EEE SSS AAAAA M M M PPPP L EEE % |
| 9 | % R R E SS A A M M P L E % |
| 10 | % R R EEEEE SSSSS A A M M P LLLLL EEEEE % |
| 11 | % % |
| 12 | % % |
| 13 | % MagickCore Pixel Resampling Methods % |
| 14 | % % |
| 15 | % Software Design % |
| 16 | % John Cristy % |
| 17 | % Anthony Thyssen % |
| 18 | % August 2007 % |
| 19 | % % |
| 20 | % % |
cristy | 16af1cb | 2009-12-11 21:38:29 +0000 | [diff] [blame^] | 21 | % Copyright 1999-2010 ImageMagick Studio LLC, a non-profit organization % |
cristy | 3ed852e | 2009-09-05 21:47:34 +0000 | [diff] [blame] | 22 | % dedicated to making software imaging solutions freely available. % |
| 23 | % % |
| 24 | % You may not use this file except in compliance with the License. You may % |
| 25 | % obtain a copy of the License at % |
| 26 | % % |
| 27 | % http://www.imagemagick.org/script/license.php % |
| 28 | % % |
| 29 | % Unless required by applicable law or agreed to in writing, software % |
| 30 | % distributed under the License is distributed on an "AS IS" BASIS, % |
| 31 | % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. % |
| 32 | % See the License for the specific language governing permissions and % |
| 33 | % limitations under the License. % |
| 34 | % % |
| 35 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 36 | % |
| 37 | % |
| 38 | */ |
| 39 | |
| 40 | /* |
| 41 | Include declarations. |
| 42 | */ |
| 43 | #include "magick/studio.h" |
| 44 | #include "magick/artifact.h" |
| 45 | #include "magick/color-private.h" |
| 46 | #include "magick/cache.h" |
| 47 | #include "magick/draw.h" |
| 48 | #include "magick/exception-private.h" |
| 49 | #include "magick/gem.h" |
| 50 | #include "magick/image.h" |
| 51 | #include "magick/image-private.h" |
| 52 | #include "magick/log.h" |
| 53 | #include "magick/memory_.h" |
| 54 | #include "magick/pixel-private.h" |
| 55 | #include "magick/quantum.h" |
| 56 | #include "magick/random_.h" |
| 57 | #include "magick/resample.h" |
| 58 | #include "magick/resize.h" |
| 59 | #include "magick/resize-private.h" |
| 60 | #include "magick/transform.h" |
| 61 | #include "magick/signature-private.h" |
| 62 | /* |
| 63 | Typedef declarations. |
| 64 | */ |
| 65 | #define WLUT_WIDTH 1024 |
| 66 | struct _ResampleFilter |
| 67 | { |
| 68 | Image |
| 69 | *image; |
| 70 | |
| 71 | CacheView |
| 72 | *view; |
| 73 | |
| 74 | ExceptionInfo |
| 75 | *exception; |
| 76 | |
| 77 | MagickBooleanType |
| 78 | debug; |
| 79 | |
| 80 | /* Information about image being resampled */ |
| 81 | long |
| 82 | image_area; |
| 83 | |
| 84 | InterpolatePixelMethod |
| 85 | interpolate; |
| 86 | |
| 87 | VirtualPixelMethod |
| 88 | virtual_pixel; |
| 89 | |
| 90 | FilterTypes |
| 91 | filter; |
| 92 | |
| 93 | /* processing settings needed */ |
| 94 | MagickBooleanType |
| 95 | limit_reached, |
| 96 | do_interpolate, |
| 97 | average_defined; |
| 98 | |
| 99 | MagickPixelPacket |
| 100 | average_pixel; |
| 101 | |
| 102 | /* current ellipitical area being resampled around center point */ |
| 103 | double |
| 104 | A, B, C, |
| 105 | sqrtA, sqrtC, sqrtU, slope; |
| 106 | |
| 107 | /* LUT of weights for filtered average in elliptical area */ |
| 108 | double |
| 109 | filter_lut[WLUT_WIDTH], |
| 110 | support; |
| 111 | |
| 112 | unsigned long |
| 113 | signature; |
| 114 | }; |
| 115 | |
| 116 | /* |
| 117 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 118 | % % |
| 119 | % % |
| 120 | % % |
| 121 | % A c q u i r e R e s a m p l e I n f o % |
| 122 | % % |
| 123 | % % |
| 124 | % % |
| 125 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 126 | % |
| 127 | % AcquireResampleFilter() initializes the information resample needs do to a |
| 128 | % scaled lookup of a color from an image, using area sampling. |
| 129 | % |
| 130 | % The algorithm is based on a Elliptical Weighted Average, where the pixels |
| 131 | % found in a large elliptical area is averaged together according to a |
| 132 | % weighting (filter) function. For more details see "Fundamentals of Texture |
| 133 | % Mapping and Image Warping" a master's thesis by Paul.S.Heckbert, June 17, |
| 134 | % 1989. Available for free from, http://www.cs.cmu.edu/~ph/ |
| 135 | % |
| 136 | % As EWA resampling (or any sort of resampling) can require a lot of |
| 137 | % calculations to produce a distorted scaling of the source image for each |
| 138 | % output pixel, the ResampleFilter structure generated holds that information |
| 139 | % between individual image resampling. |
| 140 | % |
| 141 | % This function will make the appropriate AcquireCacheView() calls |
| 142 | % to view the image, calling functions do not need to open a cache view. |
| 143 | % |
| 144 | % Usage Example... |
| 145 | % resample_filter=AcquireResampleFilter(image,exception); |
| 146 | % for (y=0; y < (long) image->rows; y++) { |
| 147 | % for (x=0; x < (long) image->columns; x++) { |
| 148 | % X= ....; Y= ....; |
| 149 | % ScaleResampleFilter(resample_filter, ... scaling vectors ...); |
| 150 | % (void) ResamplePixelColor(resample_filter,X,Y,&pixel); |
| 151 | % ... assign resampled pixel value ... |
| 152 | % } |
| 153 | % } |
| 154 | % DestroyResampleFilter(resample_filter); |
| 155 | % |
| 156 | % The format of the AcquireResampleFilter method is: |
| 157 | % |
| 158 | % ResampleFilter *AcquireResampleFilter(const Image *image, |
| 159 | % ExceptionInfo *exception) |
| 160 | % |
| 161 | % A description of each parameter follows: |
| 162 | % |
| 163 | % o image: the image. |
| 164 | % |
| 165 | % o exception: return any errors or warnings in this structure. |
| 166 | % |
| 167 | */ |
| 168 | MagickExport ResampleFilter *AcquireResampleFilter(const Image *image, |
| 169 | ExceptionInfo *exception) |
| 170 | { |
| 171 | register ResampleFilter |
| 172 | *resample_filter; |
| 173 | |
| 174 | assert(image != (Image *) NULL); |
| 175 | assert(image->signature == MagickSignature); |
| 176 | if (image->debug != MagickFalse) |
| 177 | (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename); |
| 178 | assert(exception != (ExceptionInfo *) NULL); |
| 179 | assert(exception->signature == MagickSignature); |
| 180 | |
| 181 | resample_filter=(ResampleFilter *) AcquireMagickMemory( |
| 182 | sizeof(*resample_filter)); |
| 183 | if (resample_filter == (ResampleFilter *) NULL) |
| 184 | ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed"); |
| 185 | (void) ResetMagickMemory(resample_filter,0,sizeof(*resample_filter)); |
| 186 | |
| 187 | resample_filter->image=ReferenceImage((Image *) image); |
| 188 | resample_filter->view=AcquireCacheView(resample_filter->image); |
| 189 | resample_filter->exception=exception; |
| 190 | |
| 191 | resample_filter->debug=IsEventLogging(); |
| 192 | resample_filter->signature=MagickSignature; |
| 193 | |
| 194 | resample_filter->image_area = (long) resample_filter->image->columns * |
| 195 | resample_filter->image->rows; |
| 196 | resample_filter->average_defined = MagickFalse; |
| 197 | |
| 198 | /* initialise the resampling filter settings */ |
| 199 | SetResampleFilter(resample_filter, resample_filter->image->filter, |
| 200 | resample_filter->image->blur); |
| 201 | resample_filter->interpolate = resample_filter->image->interpolate; |
| 202 | resample_filter->virtual_pixel=GetImageVirtualPixelMethod(image); |
| 203 | |
| 204 | /* init scale to a default of a unit circle */ |
| 205 | ScaleResampleFilter(resample_filter, 1.0, 0.0, 0.0, 1.0); |
| 206 | |
| 207 | return(resample_filter); |
| 208 | } |
| 209 | |
| 210 | /* |
| 211 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 212 | % % |
| 213 | % % |
| 214 | % % |
| 215 | % D e s t r o y R e s a m p l e I n f o % |
| 216 | % % |
| 217 | % % |
| 218 | % % |
| 219 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 220 | % |
| 221 | % DestroyResampleFilter() finalizes and cleans up the resampling |
| 222 | % resample_filter as returned by AcquireResampleFilter(), freeing any memory |
| 223 | % or other information as needed. |
| 224 | % |
| 225 | % The format of the DestroyResampleFilter method is: |
| 226 | % |
| 227 | % ResampleFilter *DestroyResampleFilter(ResampleFilter *resample_filter) |
| 228 | % |
| 229 | % A description of each parameter follows: |
| 230 | % |
| 231 | % o resample_filter: resampling information structure |
| 232 | % |
| 233 | */ |
| 234 | MagickExport ResampleFilter *DestroyResampleFilter( |
| 235 | ResampleFilter *resample_filter) |
| 236 | { |
| 237 | assert(resample_filter != (ResampleFilter *) NULL); |
| 238 | assert(resample_filter->signature == MagickSignature); |
| 239 | assert(resample_filter->image != (Image *) NULL); |
| 240 | if (resample_filter->debug != MagickFalse) |
| 241 | (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s", |
| 242 | resample_filter->image->filename); |
| 243 | resample_filter->view=DestroyCacheView(resample_filter->view); |
| 244 | resample_filter->image=DestroyImage(resample_filter->image); |
| 245 | resample_filter->signature=(~MagickSignature); |
| 246 | resample_filter=(ResampleFilter *) RelinquishMagickMemory(resample_filter); |
| 247 | return(resample_filter); |
| 248 | } |
| 249 | |
| 250 | /* |
| 251 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 252 | % % |
| 253 | % % |
| 254 | % % |
| 255 | % I n t e r p o l a t e R e s a m p l e F i l t e r % |
| 256 | % % |
| 257 | % % |
| 258 | % % |
| 259 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 260 | % |
| 261 | % InterpolateResampleFilter() applies bi-linear or tri-linear interpolation |
| 262 | % between a floating point coordinate and the pixels surrounding that |
| 263 | % coordinate. No pixel area resampling, or scaling of the result is |
| 264 | % performed. |
| 265 | % |
| 266 | % The format of the InterpolateResampleFilter method is: |
| 267 | % |
| 268 | % MagickBooleanType InterpolateResampleFilter( |
| 269 | % ResampleInfo *resample_filter,const InterpolatePixelMethod method, |
| 270 | % const double x,const double y,MagickPixelPacket *pixel) |
| 271 | % |
| 272 | % A description of each parameter follows: |
| 273 | % |
| 274 | % o resample_filter: the resample filter. |
| 275 | % |
| 276 | % o method: the pixel clor interpolation method. |
| 277 | % |
| 278 | % o x,y: A double representing the current (x,y) position of the pixel. |
| 279 | % |
| 280 | % o pixel: return the interpolated pixel here. |
| 281 | % |
| 282 | */ |
| 283 | |
| 284 | static inline double MagickMax(const double x,const double y) |
| 285 | { |
| 286 | if (x > y) |
| 287 | return(x); |
| 288 | return(y); |
| 289 | } |
| 290 | |
| 291 | static void BicubicInterpolate(const MagickPixelPacket *pixels,const double dx, |
| 292 | MagickPixelPacket *pixel) |
| 293 | { |
| 294 | MagickRealType |
| 295 | dx2, |
| 296 | p, |
| 297 | q, |
| 298 | r, |
| 299 | s; |
| 300 | |
| 301 | dx2=dx*dx; |
| 302 | p=(pixels[3].red-pixels[2].red)-(pixels[0].red-pixels[1].red); |
| 303 | q=(pixels[0].red-pixels[1].red)-p; |
| 304 | r=pixels[2].red-pixels[0].red; |
| 305 | s=pixels[1].red; |
| 306 | pixel->red=(dx*dx2*p)+(dx2*q)+(dx*r)+s; |
| 307 | p=(pixels[3].green-pixels[2].green)-(pixels[0].green-pixels[1].green); |
| 308 | q=(pixels[0].green-pixels[1].green)-p; |
| 309 | r=pixels[2].green-pixels[0].green; |
| 310 | s=pixels[1].green; |
| 311 | pixel->green=(dx*dx2*p)+(dx2*q)+(dx*r)+s; |
| 312 | p=(pixels[3].blue-pixels[2].blue)-(pixels[0].blue-pixels[1].blue); |
| 313 | q=(pixels[0].blue-pixels[1].blue)-p; |
| 314 | r=pixels[2].blue-pixels[0].blue; |
| 315 | s=pixels[1].blue; |
| 316 | pixel->blue=(dx*dx2*p)+(dx2*q)+(dx*r)+s; |
| 317 | p=(pixels[3].opacity-pixels[2].opacity)-(pixels[0].opacity-pixels[1].opacity); |
| 318 | q=(pixels[0].opacity-pixels[1].opacity)-p; |
| 319 | r=pixels[2].opacity-pixels[0].opacity; |
| 320 | s=pixels[1].opacity; |
| 321 | pixel->opacity=(dx*dx2*p)+(dx2*q)+(dx*r)+s; |
| 322 | if (pixel->colorspace == CMYKColorspace) |
| 323 | { |
| 324 | p=(pixels[3].index-pixels[2].index)-(pixels[0].index-pixels[1].index); |
| 325 | q=(pixels[0].index-pixels[1].index)-p; |
| 326 | r=pixels[2].index-pixels[0].index; |
| 327 | s=pixels[1].index; |
| 328 | pixel->index=(dx*dx2*p)+(dx2*q)+(dx*r)+s; |
| 329 | } |
| 330 | } |
| 331 | |
| 332 | static inline MagickRealType CubicWeightingFunction(const MagickRealType x) |
| 333 | { |
| 334 | MagickRealType |
| 335 | alpha, |
| 336 | gamma; |
| 337 | |
| 338 | alpha=MagickMax(x+2.0,0.0); |
| 339 | gamma=1.0*alpha*alpha*alpha; |
| 340 | alpha=MagickMax(x+1.0,0.0); |
| 341 | gamma-=4.0*alpha*alpha*alpha; |
| 342 | alpha=MagickMax(x+0.0,0.0); |
| 343 | gamma+=6.0*alpha*alpha*alpha; |
| 344 | alpha=MagickMax(x-1.0,0.0); |
| 345 | gamma-=4.0*alpha*alpha*alpha; |
| 346 | return(gamma/6.0); |
| 347 | } |
| 348 | |
| 349 | static inline double MeshInterpolate(const PointInfo *delta,const double p, |
| 350 | const double x,const double y) |
| 351 | { |
| 352 | return(delta->x*x+delta->y*y+(1.0-delta->x-delta->y)*p); |
| 353 | } |
| 354 | |
| 355 | static inline long NearestNeighbor(MagickRealType x) |
| 356 | { |
| 357 | if (x >= 0.0) |
| 358 | return((long) (x+0.5)); |
| 359 | return((long) (x-0.5)); |
| 360 | } |
| 361 | |
| 362 | static MagickBooleanType InterpolateResampleFilter( |
| 363 | ResampleFilter *resample_filter,const InterpolatePixelMethod method, |
| 364 | const double x,const double y,MagickPixelPacket *pixel) |
| 365 | { |
| 366 | MagickBooleanType |
| 367 | status; |
| 368 | |
| 369 | register const IndexPacket |
| 370 | *indexes; |
| 371 | |
| 372 | register const PixelPacket |
| 373 | *p; |
| 374 | |
| 375 | register long |
| 376 | i; |
| 377 | |
| 378 | assert(resample_filter != (ResampleFilter *) NULL); |
| 379 | assert(resample_filter->signature == MagickSignature); |
| 380 | status=MagickTrue; |
| 381 | switch (method) |
| 382 | { |
| 383 | case AverageInterpolatePixel: |
| 384 | { |
| 385 | MagickPixelPacket |
| 386 | pixels[16]; |
| 387 | |
| 388 | MagickRealType |
| 389 | alpha[16], |
| 390 | gamma; |
| 391 | |
| 392 | p=GetCacheViewVirtualPixels(resample_filter->view,(long) floor(x)-1,(long) |
| 393 | floor(y)-1,4,4,resample_filter->exception); |
| 394 | if (p == (const PixelPacket *) NULL) |
| 395 | { |
| 396 | status=MagickFalse; |
| 397 | break; |
| 398 | } |
| 399 | indexes=GetCacheViewVirtualIndexQueue(resample_filter->view); |
| 400 | for (i=0; i < 16L; i++) |
| 401 | { |
| 402 | GetMagickPixelPacket(resample_filter->image,pixels+i); |
| 403 | SetMagickPixelPacket(resample_filter->image,p,indexes+i,pixels+i); |
| 404 | alpha[i]=1.0; |
| 405 | if (resample_filter->image->matte != MagickFalse) |
| 406 | { |
| 407 | alpha[i]=QuantumScale*((MagickRealType) QuantumRange-p->opacity); |
| 408 | pixels[i].red*=alpha[i]; |
| 409 | pixels[i].green*=alpha[i]; |
| 410 | pixels[i].blue*=alpha[i]; |
| 411 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 412 | pixels[i].index*=alpha[i]; |
| 413 | } |
| 414 | gamma=alpha[i]; |
| 415 | gamma=1.0/(fabs((double) gamma) <= MagickEpsilon ? 1.0 : gamma); |
| 416 | pixel->red+=gamma*0.0625*pixels[i].red; |
| 417 | pixel->green+=gamma*0.0625*pixels[i].green; |
| 418 | pixel->blue+=gamma*0.0625*pixels[i].blue; |
| 419 | pixel->opacity+=0.0625*pixels[i].opacity; |
| 420 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 421 | pixel->index+=gamma*0.0625*pixels[i].index; |
| 422 | p++; |
| 423 | } |
| 424 | break; |
| 425 | } |
| 426 | case BicubicInterpolatePixel: |
| 427 | { |
| 428 | MagickPixelPacket |
| 429 | pixels[16], |
| 430 | u[4]; |
| 431 | |
| 432 | MagickRealType |
| 433 | alpha[16]; |
| 434 | |
| 435 | PointInfo |
| 436 | delta; |
| 437 | |
| 438 | p=GetCacheViewVirtualPixels(resample_filter->view,(long) floor(x)-1,(long) |
| 439 | floor(y)-1,4,4,resample_filter->exception); |
| 440 | if (p == (const PixelPacket *) NULL) |
| 441 | { |
| 442 | status=MagickFalse; |
| 443 | break; |
| 444 | } |
| 445 | indexes=GetCacheViewVirtualIndexQueue(resample_filter->view); |
| 446 | for (i=0; i < 16L; i++) |
| 447 | { |
| 448 | GetMagickPixelPacket(resample_filter->image,pixels+i); |
| 449 | SetMagickPixelPacket(resample_filter->image,p,indexes+i,pixels+i); |
| 450 | alpha[i]=1.0; |
| 451 | if (resample_filter->image->matte != MagickFalse) |
| 452 | { |
| 453 | alpha[i]=QuantumScale*((MagickRealType) QuantumRange-p->opacity); |
| 454 | pixels[i].red*=alpha[i]; |
| 455 | pixels[i].green*=alpha[i]; |
| 456 | pixels[i].blue*=alpha[i]; |
| 457 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 458 | pixels[i].index*=alpha[i]; |
| 459 | } |
| 460 | p++; |
| 461 | } |
| 462 | delta.x=x-floor(x); |
| 463 | for (i=0; i < 4L; i++) |
| 464 | BicubicInterpolate(pixels+4*i,delta.x,u+i); |
| 465 | delta.y=y-floor(y); |
| 466 | BicubicInterpolate(u,delta.y,pixel); |
| 467 | break; |
| 468 | } |
| 469 | case BilinearInterpolatePixel: |
| 470 | default: |
| 471 | { |
| 472 | MagickPixelPacket |
| 473 | pixels[4]; |
| 474 | |
| 475 | MagickRealType |
| 476 | alpha[4], |
| 477 | gamma; |
| 478 | |
| 479 | PointInfo |
| 480 | delta, |
| 481 | epsilon; |
| 482 | |
| 483 | p=GetCacheViewVirtualPixels(resample_filter->view,(long) floor(x),(long) |
| 484 | floor(y),2,2,resample_filter->exception); |
| 485 | if (p == (const PixelPacket *) NULL) |
| 486 | { |
| 487 | status=MagickFalse; |
| 488 | break; |
| 489 | } |
| 490 | indexes=GetCacheViewVirtualIndexQueue(resample_filter->view); |
| 491 | for (i=0; i < 4L; i++) |
| 492 | { |
| 493 | pixels[i].red=(MagickRealType) p[i].red; |
| 494 | pixels[i].green=(MagickRealType) p[i].green; |
| 495 | pixels[i].blue=(MagickRealType) p[i].blue; |
| 496 | pixels[i].opacity=(MagickRealType) p[i].opacity; |
| 497 | alpha[i]=1.0; |
| 498 | } |
| 499 | if (resample_filter->image->matte != MagickFalse) |
| 500 | for (i=0; i < 4L; i++) |
| 501 | { |
| 502 | alpha[i]=QuantumScale*((MagickRealType) QuantumRange-p[i].opacity); |
| 503 | pixels[i].red*=alpha[i]; |
| 504 | pixels[i].green*=alpha[i]; |
| 505 | pixels[i].blue*=alpha[i]; |
| 506 | } |
| 507 | if (indexes != (IndexPacket *) NULL) |
| 508 | for (i=0; i < 4L; i++) |
| 509 | { |
| 510 | pixels[i].index=(MagickRealType) indexes[i]; |
| 511 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 512 | pixels[i].index*=alpha[i]; |
| 513 | } |
| 514 | delta.x=x-floor(x); |
| 515 | delta.y=y-floor(y); |
| 516 | epsilon.x=1.0-delta.x; |
| 517 | epsilon.y=1.0-delta.y; |
| 518 | gamma=((epsilon.y*(epsilon.x*alpha[0]+delta.x*alpha[1])+delta.y* |
| 519 | (epsilon.x*alpha[2]+delta.x*alpha[3]))); |
| 520 | gamma=1.0/(fabs((double) gamma) <= MagickEpsilon ? 1.0 : gamma); |
| 521 | pixel->red=gamma*(epsilon.y*(epsilon.x*pixels[0].red+delta.x* |
| 522 | pixels[1].red)+delta.y*(epsilon.x*pixels[2].red+delta.x*pixels[3].red)); |
| 523 | pixel->green=gamma*(epsilon.y*(epsilon.x*pixels[0].green+delta.x* |
| 524 | pixels[1].green)+delta.y*(epsilon.x*pixels[2].green+delta.x* |
| 525 | pixels[3].green)); |
| 526 | pixel->blue=gamma*(epsilon.y*(epsilon.x*pixels[0].blue+delta.x* |
| 527 | pixels[1].blue)+delta.y*(epsilon.x*pixels[2].blue+delta.x* |
| 528 | pixels[3].blue)); |
| 529 | pixel->opacity=(epsilon.y*(epsilon.x*pixels[0].opacity+delta.x* |
| 530 | pixels[1].opacity)+delta.y*(epsilon.x*pixels[2].opacity+delta.x* |
| 531 | pixels[3].opacity)); |
| 532 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 533 | pixel->index=gamma*(epsilon.y*(epsilon.x*pixels[0].index+delta.x* |
| 534 | pixels[1].index)+delta.y*(epsilon.x*pixels[2].index+delta.x* |
| 535 | pixels[3].index)); |
| 536 | break; |
| 537 | } |
| 538 | case FilterInterpolatePixel: |
| 539 | { |
| 540 | Image |
| 541 | *excerpt_image, |
| 542 | *filter_image; |
| 543 | |
| 544 | MagickPixelPacket |
| 545 | pixels[1]; |
| 546 | |
| 547 | RectangleInfo |
| 548 | geometry; |
| 549 | |
| 550 | CacheView |
| 551 | *filter_view; |
| 552 | |
| 553 | geometry.width=4L; |
| 554 | geometry.height=4L; |
| 555 | geometry.x=(long) floor(x)-1L; |
| 556 | geometry.y=(long) floor(y)-1L; |
| 557 | excerpt_image=ExcerptImage(resample_filter->image,&geometry, |
| 558 | resample_filter->exception); |
| 559 | if (excerpt_image == (Image *) NULL) |
| 560 | { |
| 561 | status=MagickFalse; |
| 562 | break; |
| 563 | } |
| 564 | filter_image=ResizeImage(excerpt_image,1,1,resample_filter->image->filter, |
| 565 | resample_filter->image->blur,resample_filter->exception); |
| 566 | excerpt_image=DestroyImage(excerpt_image); |
| 567 | if (filter_image == (Image *) NULL) |
| 568 | break; |
| 569 | filter_view=AcquireCacheView(filter_image); |
| 570 | p=GetCacheViewVirtualPixels(filter_view,0,0,1,1, |
| 571 | resample_filter->exception); |
| 572 | if (p != (const PixelPacket *) NULL) |
| 573 | { |
| 574 | indexes=GetVirtualIndexQueue(filter_image); |
| 575 | GetMagickPixelPacket(resample_filter->image,pixels); |
| 576 | SetMagickPixelPacket(resample_filter->image,p,indexes,pixel); |
| 577 | } |
| 578 | filter_view=DestroyCacheView(filter_view); |
| 579 | filter_image=DestroyImage(filter_image); |
| 580 | break; |
| 581 | } |
| 582 | case IntegerInterpolatePixel: |
| 583 | { |
| 584 | MagickPixelPacket |
| 585 | pixels[1]; |
| 586 | |
| 587 | p=GetCacheViewVirtualPixels(resample_filter->view,(long) floor(x),(long) |
| 588 | floor(y),1,1,resample_filter->exception); |
| 589 | if (p == (const PixelPacket *) NULL) |
| 590 | { |
| 591 | status=MagickFalse; |
| 592 | break; |
| 593 | } |
| 594 | indexes=GetCacheViewVirtualIndexQueue(resample_filter->view); |
| 595 | GetMagickPixelPacket(resample_filter->image,pixels); |
| 596 | SetMagickPixelPacket(resample_filter->image,p,indexes,pixel); |
| 597 | break; |
| 598 | } |
| 599 | case MeshInterpolatePixel: |
| 600 | { |
| 601 | MagickPixelPacket |
| 602 | pixels[4]; |
| 603 | |
| 604 | MagickRealType |
| 605 | alpha[4], |
| 606 | gamma; |
| 607 | |
| 608 | PointInfo |
| 609 | delta, |
| 610 | luminance; |
| 611 | |
| 612 | p=GetCacheViewVirtualPixels(resample_filter->view,(long) floor(x),(long) |
| 613 | floor(y),2,2,resample_filter->exception); |
| 614 | if (p == (const PixelPacket *) NULL) |
| 615 | { |
| 616 | status=MagickFalse; |
| 617 | break; |
| 618 | } |
| 619 | indexes=GetCacheViewVirtualIndexQueue(resample_filter->view); |
| 620 | for (i=0; i < 4L; i++) |
| 621 | { |
| 622 | GetMagickPixelPacket(resample_filter->image,pixels+i); |
| 623 | SetMagickPixelPacket(resample_filter->image,p,indexes+i,pixels+i); |
| 624 | alpha[i]=1.0; |
| 625 | if (resample_filter->image->matte != MagickFalse) |
| 626 | { |
| 627 | alpha[i]=QuantumScale*((MagickRealType) QuantumRange-p->opacity); |
| 628 | pixels[i].red*=alpha[i]; |
| 629 | pixels[i].green*=alpha[i]; |
| 630 | pixels[i].blue*=alpha[i]; |
| 631 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 632 | pixels[i].index*=alpha[i]; |
| 633 | } |
| 634 | p++; |
| 635 | } |
| 636 | delta.x=x-floor(x); |
| 637 | delta.y=y-floor(y); |
| 638 | luminance.x=MagickPixelLuminance(pixels+0)-MagickPixelLuminance(pixels+3); |
| 639 | luminance.y=MagickPixelLuminance(pixels+1)-MagickPixelLuminance(pixels+2); |
| 640 | if (fabs(luminance.x) < fabs(luminance.y)) |
| 641 | { |
| 642 | /* |
| 643 | Diagonal 0-3 NW-SE. |
| 644 | */ |
| 645 | if (delta.x <= delta.y) |
| 646 | { |
| 647 | /* |
| 648 | Bottom-left triangle (pixel:2, diagonal: 0-3). |
| 649 | */ |
| 650 | delta.y=1.0-delta.y; |
| 651 | gamma=MeshInterpolate(&delta,alpha[2],alpha[3],alpha[0]); |
| 652 | gamma=1.0/(fabs((double) gamma) <= MagickEpsilon ? 1.0 : gamma); |
| 653 | pixel->red=gamma*MeshInterpolate(&delta,pixels[2].red, |
| 654 | pixels[3].red,pixels[0].red); |
| 655 | pixel->green=gamma*MeshInterpolate(&delta,pixels[2].green, |
| 656 | pixels[3].green,pixels[0].green); |
| 657 | pixel->blue=gamma*MeshInterpolate(&delta,pixels[2].blue, |
| 658 | pixels[3].blue,pixels[0].blue); |
| 659 | pixel->opacity=gamma*MeshInterpolate(&delta,pixels[2].opacity, |
| 660 | pixels[3].opacity,pixels[0].opacity); |
| 661 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 662 | pixel->index=gamma*MeshInterpolate(&delta,pixels[2].index, |
| 663 | pixels[3].index,pixels[0].index); |
| 664 | } |
| 665 | else |
| 666 | { |
| 667 | /* |
| 668 | Top-right triangle (pixel:1, diagonal: 0-3). |
| 669 | */ |
| 670 | delta.x=1.0-delta.x; |
| 671 | gamma=MeshInterpolate(&delta,alpha[1],alpha[0],alpha[3]); |
| 672 | gamma=1.0/(fabs((double) gamma) <= MagickEpsilon ? 1.0 : gamma); |
| 673 | pixel->red=gamma*MeshInterpolate(&delta,pixels[1].red, |
| 674 | pixels[0].red,pixels[3].red); |
| 675 | pixel->green=gamma*MeshInterpolate(&delta,pixels[1].green, |
| 676 | pixels[0].green,pixels[3].green); |
| 677 | pixel->blue=gamma*MeshInterpolate(&delta,pixels[1].blue, |
| 678 | pixels[0].blue,pixels[3].blue); |
| 679 | pixel->opacity=gamma*MeshInterpolate(&delta,pixels[1].opacity, |
| 680 | pixels[0].opacity,pixels[3].opacity); |
| 681 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 682 | pixel->index=gamma*MeshInterpolate(&delta,pixels[1].index, |
| 683 | pixels[0].index,pixels[3].index); |
| 684 | } |
| 685 | } |
| 686 | else |
| 687 | { |
| 688 | /* |
| 689 | Diagonal 1-2 NE-SW. |
| 690 | */ |
| 691 | if (delta.x <= (1.0-delta.y)) |
| 692 | { |
| 693 | /* |
| 694 | Top-left triangle (pixel 0, diagonal: 1-2). |
| 695 | */ |
| 696 | gamma=MeshInterpolate(&delta,alpha[0],alpha[1],alpha[2]); |
| 697 | gamma=1.0/(fabs((double) gamma) <= MagickEpsilon ? 1.0 : gamma); |
| 698 | pixel->red=gamma*MeshInterpolate(&delta,pixels[0].red, |
| 699 | pixels[1].red,pixels[2].red); |
| 700 | pixel->green=gamma*MeshInterpolate(&delta,pixels[0].green, |
| 701 | pixels[1].green,pixels[2].green); |
| 702 | pixel->blue=gamma*MeshInterpolate(&delta,pixels[0].blue, |
| 703 | pixels[1].blue,pixels[2].blue); |
| 704 | pixel->opacity=gamma*MeshInterpolate(&delta,pixels[0].opacity, |
| 705 | pixels[1].opacity,pixels[2].opacity); |
| 706 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 707 | pixel->index=gamma*MeshInterpolate(&delta,pixels[0].index, |
| 708 | pixels[1].index,pixels[2].index); |
| 709 | } |
| 710 | else |
| 711 | { |
| 712 | /* |
| 713 | Bottom-right triangle (pixel: 3, diagonal: 1-2). |
| 714 | */ |
| 715 | delta.x=1.0-delta.x; |
| 716 | delta.y=1.0-delta.y; |
| 717 | gamma=MeshInterpolate(&delta,alpha[3],alpha[2],alpha[1]); |
| 718 | gamma=1.0/(fabs((double) gamma) <= MagickEpsilon ? 1.0 : gamma); |
| 719 | pixel->red=gamma*MeshInterpolate(&delta,pixels[3].red, |
| 720 | pixels[2].red,pixels[1].red); |
| 721 | pixel->green=gamma*MeshInterpolate(&delta,pixels[3].green, |
| 722 | pixels[2].green,pixels[1].green); |
| 723 | pixel->blue=gamma*MeshInterpolate(&delta,pixels[3].blue, |
| 724 | pixels[2].blue,pixels[1].blue); |
| 725 | pixel->opacity=gamma*MeshInterpolate(&delta,pixels[3].opacity, |
| 726 | pixels[2].opacity,pixels[1].opacity); |
| 727 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 728 | pixel->index=gamma*MeshInterpolate(&delta,pixels[3].index, |
| 729 | pixels[2].index,pixels[1].index); |
| 730 | } |
| 731 | } |
| 732 | break; |
| 733 | } |
| 734 | case NearestNeighborInterpolatePixel: |
| 735 | { |
| 736 | MagickPixelPacket |
| 737 | pixels[1]; |
| 738 | |
| 739 | p=GetCacheViewVirtualPixels(resample_filter->view,NearestNeighbor(x), |
| 740 | NearestNeighbor(y),1,1,resample_filter->exception); |
| 741 | if (p == (const PixelPacket *) NULL) |
| 742 | { |
| 743 | status=MagickFalse; |
| 744 | break; |
| 745 | } |
| 746 | indexes=GetCacheViewVirtualIndexQueue(resample_filter->view); |
| 747 | GetMagickPixelPacket(resample_filter->image,pixels); |
| 748 | SetMagickPixelPacket(resample_filter->image,p,indexes,pixel); |
| 749 | break; |
| 750 | } |
| 751 | case SplineInterpolatePixel: |
| 752 | { |
| 753 | long |
| 754 | j, |
| 755 | n; |
| 756 | |
| 757 | MagickPixelPacket |
| 758 | pixels[16]; |
| 759 | |
| 760 | MagickRealType |
| 761 | alpha[16], |
| 762 | dx, |
| 763 | dy, |
| 764 | gamma; |
| 765 | |
| 766 | PointInfo |
| 767 | delta; |
| 768 | |
| 769 | p=GetCacheViewVirtualPixels(resample_filter->view,(long) floor(x)-1,(long) |
| 770 | floor(y)-1,4,4,resample_filter->exception); |
| 771 | if (p == (const PixelPacket *) NULL) |
| 772 | { |
| 773 | status=MagickFalse; |
| 774 | break; |
| 775 | } |
| 776 | indexes=GetCacheViewVirtualIndexQueue(resample_filter->view); |
| 777 | n=0; |
| 778 | delta.x=x-floor(x); |
| 779 | delta.y=y-floor(y); |
| 780 | for (i=(-1); i < 3L; i++) |
| 781 | { |
| 782 | dy=CubicWeightingFunction((MagickRealType) i-delta.y); |
| 783 | for (j=(-1); j < 3L; j++) |
| 784 | { |
| 785 | GetMagickPixelPacket(resample_filter->image,pixels+n); |
| 786 | SetMagickPixelPacket(resample_filter->image,p,indexes+n,pixels+n); |
| 787 | alpha[n]=1.0; |
| 788 | if (resample_filter->image->matte != MagickFalse) |
| 789 | { |
| 790 | alpha[n]=QuantumScale*((MagickRealType) QuantumRange-p->opacity); |
| 791 | pixels[n].red*=alpha[n]; |
| 792 | pixels[n].green*=alpha[n]; |
| 793 | pixels[n].blue*=alpha[n]; |
| 794 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 795 | pixels[n].index*=alpha[n]; |
| 796 | } |
| 797 | dx=CubicWeightingFunction(delta.x-(MagickRealType) j); |
| 798 | gamma=alpha[n]; |
| 799 | gamma=1.0/(fabs((double) gamma) <= MagickEpsilon ? 1.0 : gamma); |
| 800 | pixel->red+=gamma*dx*dy*pixels[n].red; |
| 801 | pixel->green+=gamma*dx*dy*pixels[n].green; |
| 802 | pixel->blue+=gamma*dx*dy*pixels[n].blue; |
| 803 | if (resample_filter->image->matte != MagickFalse) |
| 804 | pixel->opacity+=dx*dy*pixels[n].opacity; |
| 805 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 806 | pixel->index+=gamma*dx*dy*pixels[n].index; |
| 807 | n++; |
| 808 | p++; |
| 809 | } |
| 810 | } |
| 811 | break; |
| 812 | } |
| 813 | } |
| 814 | return(status); |
| 815 | } |
| 816 | |
| 817 | /* |
| 818 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 819 | % % |
| 820 | % % |
| 821 | % % |
| 822 | % R e s a m p l e P i x e l C o l o r % |
| 823 | % % |
| 824 | % % |
| 825 | % % |
| 826 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 827 | % |
| 828 | % ResamplePixelColor() samples the pixel values surrounding the location |
| 829 | % given using an elliptical weighted average, at the scale previously |
| 830 | % calculated, and in the most efficent manner possible for the |
| 831 | % VirtualPixelMethod setting. |
| 832 | % |
| 833 | % The format of the ResamplePixelColor method is: |
| 834 | % |
| 835 | % MagickBooleanType ResamplePixelColor(ResampleFilter *resample_filter, |
| 836 | % const double u0,const double v0,MagickPixelPacket *pixel) |
| 837 | % |
| 838 | % A description of each parameter follows: |
| 839 | % |
| 840 | % o resample_filter: the resample filter. |
| 841 | % |
| 842 | % o u0,v0: A double representing the center of the area to resample, |
| 843 | % The distortion transformed transformed x,y coordinate. |
| 844 | % |
| 845 | % o pixel: the resampled pixel is returned here. |
| 846 | % |
| 847 | */ |
| 848 | MagickExport MagickBooleanType ResamplePixelColor( |
| 849 | ResampleFilter *resample_filter,const double u0,const double v0, |
| 850 | MagickPixelPacket *pixel) |
| 851 | { |
| 852 | MagickBooleanType |
| 853 | status; |
| 854 | |
| 855 | long u,v, uw,v1,v2, hit; |
| 856 | double u1; |
| 857 | double U,V,Q,DQ,DDQ; |
| 858 | double divisor_c,divisor_m; |
| 859 | register double weight; |
| 860 | register const PixelPacket *pixels; |
| 861 | register const IndexPacket *indexes; |
| 862 | assert(resample_filter != (ResampleFilter *) NULL); |
| 863 | assert(resample_filter->signature == MagickSignature); |
| 864 | |
| 865 | status=MagickTrue; |
| 866 | GetMagickPixelPacket(resample_filter->image,pixel); |
| 867 | if ( resample_filter->do_interpolate ) { |
| 868 | status=InterpolateResampleFilter(resample_filter, |
| 869 | resample_filter->interpolate,u0,v0,pixel); |
| 870 | return(status); |
| 871 | } |
| 872 | |
| 873 | /* |
| 874 | Does resample area Miss the image? |
| 875 | And is that area a simple solid color - then return that color |
| 876 | */ |
| 877 | hit = 0; |
| 878 | switch ( resample_filter->virtual_pixel ) { |
| 879 | case BackgroundVirtualPixelMethod: |
| 880 | case ConstantVirtualPixelMethod: |
| 881 | case TransparentVirtualPixelMethod: |
| 882 | case BlackVirtualPixelMethod: |
| 883 | case GrayVirtualPixelMethod: |
| 884 | case WhiteVirtualPixelMethod: |
| 885 | case MaskVirtualPixelMethod: |
| 886 | if ( resample_filter->limit_reached |
| 887 | || u0 + resample_filter->sqrtC < 0.0 |
| 888 | || u0 - resample_filter->sqrtC > (double) resample_filter->image->columns |
| 889 | || v0 + resample_filter->sqrtA < 0.0 |
| 890 | || v0 - resample_filter->sqrtA > (double) resample_filter->image->rows |
| 891 | ) |
| 892 | hit++; |
| 893 | break; |
| 894 | |
| 895 | case UndefinedVirtualPixelMethod: |
| 896 | case EdgeVirtualPixelMethod: |
| 897 | if ( ( u0 + resample_filter->sqrtC < 0.0 && v0 + resample_filter->sqrtA < 0.0 ) |
| 898 | || ( u0 + resample_filter->sqrtC < 0.0 |
| 899 | && v0 - resample_filter->sqrtA > (double) resample_filter->image->rows ) |
| 900 | || ( u0 - resample_filter->sqrtC > (double) resample_filter->image->columns |
| 901 | && v0 + resample_filter->sqrtA < 0.0 ) |
| 902 | || ( u0 - resample_filter->sqrtC > (double) resample_filter->image->columns |
| 903 | && v0 - resample_filter->sqrtA > (double) resample_filter->image->rows ) |
| 904 | ) |
| 905 | hit++; |
| 906 | break; |
| 907 | case HorizontalTileVirtualPixelMethod: |
| 908 | if ( v0 + resample_filter->sqrtA < 0.0 |
| 909 | || v0 - resample_filter->sqrtA > (double) resample_filter->image->rows |
| 910 | ) |
| 911 | hit++; /* outside the horizontally tiled images. */ |
| 912 | break; |
| 913 | case VerticalTileVirtualPixelMethod: |
| 914 | if ( u0 + resample_filter->sqrtC < 0.0 |
| 915 | || u0 - resample_filter->sqrtC > (double) resample_filter->image->columns |
| 916 | ) |
| 917 | hit++; /* outside the vertically tiled images. */ |
| 918 | break; |
| 919 | case DitherVirtualPixelMethod: |
| 920 | if ( ( u0 + resample_filter->sqrtC < -32.0 && v0 + resample_filter->sqrtA < -32.0 ) |
| 921 | || ( u0 + resample_filter->sqrtC < -32.0 |
| 922 | && v0 - resample_filter->sqrtA > (double) resample_filter->image->rows+32.0 ) |
| 923 | || ( u0 - resample_filter->sqrtC > (double) resample_filter->image->columns+32.0 |
| 924 | && v0 + resample_filter->sqrtA < -32.0 ) |
| 925 | || ( u0 - resample_filter->sqrtC > (double) resample_filter->image->columns+32.0 |
| 926 | && v0 - resample_filter->sqrtA > (double) resample_filter->image->rows+32.0 ) |
| 927 | ) |
| 928 | hit++; |
| 929 | break; |
| 930 | case TileVirtualPixelMethod: |
| 931 | case MirrorVirtualPixelMethod: |
| 932 | case RandomVirtualPixelMethod: |
| 933 | case HorizontalTileEdgeVirtualPixelMethod: |
| 934 | case VerticalTileEdgeVirtualPixelMethod: |
| 935 | case CheckerTileVirtualPixelMethod: |
| 936 | /* resampling of area is always needed - no VP limits */ |
| 937 | break; |
| 938 | } |
| 939 | if ( hit ) { |
| 940 | /* whole area is a solid color -- just return that color */ |
| 941 | status=InterpolateResampleFilter(resample_filter,IntegerInterpolatePixel, |
| 942 | u0,v0,pixel); |
| 943 | return(status); |
| 944 | } |
| 945 | |
| 946 | /* |
| 947 | Scaling limits reached, return an 'averaged' result. |
| 948 | */ |
| 949 | if ( resample_filter->limit_reached ) { |
| 950 | switch ( resample_filter->virtual_pixel ) { |
| 951 | /* This is always handled by the above, so no need. |
| 952 | case BackgroundVirtualPixelMethod: |
| 953 | case ConstantVirtualPixelMethod: |
| 954 | case TransparentVirtualPixelMethod: |
| 955 | case GrayVirtualPixelMethod, |
| 956 | case WhiteVirtualPixelMethod |
| 957 | case MaskVirtualPixelMethod: |
| 958 | */ |
| 959 | case UndefinedVirtualPixelMethod: |
| 960 | case EdgeVirtualPixelMethod: |
| 961 | case DitherVirtualPixelMethod: |
| 962 | case HorizontalTileEdgeVirtualPixelMethod: |
| 963 | case VerticalTileEdgeVirtualPixelMethod: |
| 964 | /* We need an average edge pixel, for the right edge! |
| 965 | How should I calculate an average edge color? |
| 966 | Just returning an averaged neighbourhood, |
| 967 | works well in general, but falls down for TileEdge methods. |
| 968 | This needs to be done properly!!!!!! |
| 969 | */ |
| 970 | status=InterpolateResampleFilter(resample_filter, |
| 971 | AverageInterpolatePixel,u0,v0,pixel); |
| 972 | break; |
| 973 | case HorizontalTileVirtualPixelMethod: |
| 974 | case VerticalTileVirtualPixelMethod: |
| 975 | /* just return the background pixel - Is there more direct way? */ |
| 976 | status=InterpolateResampleFilter(resample_filter, |
| 977 | IntegerInterpolatePixel,(double)-1,(double)-1,pixel); |
| 978 | break; |
| 979 | case TileVirtualPixelMethod: |
| 980 | case MirrorVirtualPixelMethod: |
| 981 | case RandomVirtualPixelMethod: |
| 982 | case CheckerTileVirtualPixelMethod: |
| 983 | default: |
| 984 | /* generate a average color of the WHOLE image */ |
| 985 | if ( resample_filter->average_defined == MagickFalse ) { |
| 986 | Image |
| 987 | *average_image; |
| 988 | |
| 989 | CacheView |
| 990 | *average_view; |
| 991 | |
| 992 | GetMagickPixelPacket(resample_filter->image, |
| 993 | (MagickPixelPacket *)&(resample_filter->average_pixel)); |
| 994 | resample_filter->average_defined = MagickTrue; |
| 995 | |
| 996 | /* Try to get an averaged pixel color of whole image */ |
| 997 | average_image=ResizeImage(resample_filter->image,1,1,BoxFilter,1.0, |
| 998 | resample_filter->exception); |
| 999 | if (average_image == (Image *) NULL) |
| 1000 | { |
| 1001 | *pixel=resample_filter->average_pixel; /* FAILED */ |
| 1002 | break; |
| 1003 | } |
| 1004 | average_view=AcquireCacheView(average_image); |
| 1005 | pixels=(PixelPacket *)GetCacheViewVirtualPixels(average_view,0,0,1,1, |
| 1006 | resample_filter->exception); |
| 1007 | if (pixels == (const PixelPacket *) NULL) { |
| 1008 | average_view=DestroyCacheView(average_view); |
| 1009 | average_image=DestroyImage(average_image); |
| 1010 | *pixel=resample_filter->average_pixel; /* FAILED */ |
| 1011 | break; |
| 1012 | } |
| 1013 | indexes=(IndexPacket *) GetCacheViewAuthenticIndexQueue(average_view); |
| 1014 | SetMagickPixelPacket(resample_filter->image,pixels,indexes, |
| 1015 | &(resample_filter->average_pixel)); |
| 1016 | average_view=DestroyCacheView(average_view); |
| 1017 | average_image=DestroyImage(average_image); |
| 1018 | #if 0 |
| 1019 | /* CheckerTile should average the image with background color */ |
| 1020 | //if ( resample_filter->virtual_pixel == CheckerTileVirtualPixelMethod ) { |
| 1021 | #if 0 |
| 1022 | resample_filter->average_pixel.red = |
| 1023 | ( resample_filter->average_pixel.red + |
| 1024 | resample_filter->image->background_color.red ) /2; |
| 1025 | resample_filter->average_pixel.green = |
| 1026 | ( resample_filter->average_pixel.green + |
| 1027 | resample_filter->image->background_color.green ) /2; |
| 1028 | resample_filter->average_pixel.blue = |
| 1029 | ( resample_filter->average_pixel.blue + |
| 1030 | resample_filter->image->background_color.blue ) /2; |
| 1031 | resample_filter->average_pixel.matte = |
| 1032 | ( resample_filter->average_pixel.matte + |
| 1033 | resample_filter->image->background_color.matte ) /2; |
| 1034 | resample_filter->average_pixel.black = |
| 1035 | ( resample_filter->average_pixel.black + |
| 1036 | resample_filter->image->background_color.black ) /2; |
| 1037 | #else |
| 1038 | resample_filter->average_pixel = |
| 1039 | resample_filter->image->background_color; |
| 1040 | #endif |
| 1041 | } |
| 1042 | #endif |
| 1043 | } |
| 1044 | *pixel=resample_filter->average_pixel; |
| 1045 | break; |
| 1046 | } |
| 1047 | return(status); |
| 1048 | } |
| 1049 | |
| 1050 | /* |
| 1051 | Initialize weighted average data collection |
| 1052 | */ |
| 1053 | hit = 0; |
| 1054 | divisor_c = 0.0; |
| 1055 | divisor_m = 0.0; |
| 1056 | pixel->red = pixel->green = pixel->blue = 0.0; |
| 1057 | if (resample_filter->image->matte != MagickFalse) pixel->opacity = 0.0; |
| 1058 | if (resample_filter->image->colorspace == CMYKColorspace) pixel->index = 0.0; |
| 1059 | |
| 1060 | /* |
| 1061 | Determine the parellelogram bounding box fitted to the ellipse |
| 1062 | centered at u0,v0. This area is bounding by the lines... |
| 1063 | v = +/- sqrt(A) |
| 1064 | u = -By/2A +/- sqrt(F/A) |
| 1065 | Which has been pre-calculated above. |
| 1066 | */ |
| 1067 | v1 = (long)(v0 - resample_filter->sqrtA); /* range of scan lines */ |
| 1068 | v2 = (long)(v0 + resample_filter->sqrtA + 1); |
| 1069 | |
| 1070 | u1 = u0 + (v1-v0)*resample_filter->slope - resample_filter->sqrtU; /* start of scanline for v=v1 */ |
| 1071 | uw = (long)(2*resample_filter->sqrtU)+1; /* width of parallelogram */ |
| 1072 | |
| 1073 | /* |
| 1074 | Do weighted resampling of all pixels, within the scaled ellipse, |
| 1075 | bound by a Parellelogram fitted to the ellipse. |
| 1076 | */ |
| 1077 | DDQ = 2*resample_filter->A; |
| 1078 | for( v=v1; v<=v2; v++, u1+=resample_filter->slope ) { |
| 1079 | u = (long)u1; /* first pixel in scanline ( floor(u1) ) */ |
| 1080 | U = (double)u-u0; /* location of that pixel, relative to u0,v0 */ |
| 1081 | V = (double)v-v0; |
| 1082 | |
| 1083 | /* Q = ellipse quotent ( if Q<F then pixel is inside ellipse) */ |
| 1084 | Q = U*(resample_filter->A*U + resample_filter->B*V) + resample_filter->C*V*V; |
| 1085 | DQ = resample_filter->A*(2.0*U+1) + resample_filter->B*V; |
| 1086 | |
| 1087 | /* get the scanline of pixels for this v */ |
| 1088 | pixels=GetCacheViewVirtualPixels(resample_filter->view,u,v,(unsigned long) uw, |
| 1089 | 1,resample_filter->exception); |
| 1090 | if (pixels == (const PixelPacket *) NULL) |
| 1091 | return(MagickFalse); |
| 1092 | indexes=GetCacheViewVirtualIndexQueue(resample_filter->view); |
| 1093 | |
| 1094 | /* count up the weighted pixel colors */ |
| 1095 | for( u=0; u<uw; u++ ) { |
| 1096 | /* Note that the ellipse has been pre-scaled so F = WLUT_WIDTH */ |
| 1097 | if ( Q < (double)WLUT_WIDTH ) { |
| 1098 | weight = resample_filter->filter_lut[(int)Q]; |
| 1099 | |
| 1100 | pixel->opacity += weight*pixels->opacity; |
| 1101 | divisor_m += weight; |
| 1102 | |
| 1103 | if (resample_filter->image->matte != MagickFalse) |
| 1104 | weight *= QuantumScale*((MagickRealType)(QuantumRange-pixels->opacity)); |
| 1105 | pixel->red += weight*pixels->red; |
| 1106 | pixel->green += weight*pixels->green; |
| 1107 | pixel->blue += weight*pixels->blue; |
| 1108 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 1109 | pixel->index += weight*(*indexes); |
| 1110 | divisor_c += weight; |
| 1111 | |
| 1112 | hit++; |
| 1113 | } |
| 1114 | pixels++; |
| 1115 | indexes++; |
| 1116 | Q += DQ; |
| 1117 | DQ += DDQ; |
| 1118 | } |
| 1119 | } |
| 1120 | |
| 1121 | /* |
| 1122 | Result sanity check -- this should NOT happen |
| 1123 | */ |
| 1124 | if ( hit < 4 || divisor_c < 1.0 ) { |
| 1125 | /* not enough pixels in resampling, resort to direct interpolation */ |
| 1126 | status=InterpolateResampleFilter(resample_filter, |
| 1127 | resample_filter->interpolate,u0,v0,pixel); |
| 1128 | return status; |
| 1129 | } |
| 1130 | |
| 1131 | /* |
| 1132 | Finialize results of resampling |
| 1133 | */ |
| 1134 | divisor_m = 1.0/divisor_m; |
| 1135 | pixel->opacity = (MagickRealType) RoundToQuantum(divisor_m*pixel->opacity); |
| 1136 | divisor_c = 1.0/divisor_c; |
| 1137 | pixel->red = (MagickRealType) RoundToQuantum(divisor_c*pixel->red); |
| 1138 | pixel->green = (MagickRealType) RoundToQuantum(divisor_c*pixel->green); |
| 1139 | pixel->blue = (MagickRealType) RoundToQuantum(divisor_c*pixel->blue); |
| 1140 | if (resample_filter->image->colorspace == CMYKColorspace) |
| 1141 | pixel->index = (MagickRealType) RoundToQuantum(divisor_c*pixel->index); |
| 1142 | return(MagickTrue); |
| 1143 | } |
| 1144 | |
| 1145 | /* |
| 1146 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 1147 | % % |
| 1148 | % % |
| 1149 | % % |
| 1150 | % S c a l e R e s a m p l e F i l t e r % |
| 1151 | % % |
| 1152 | % % |
| 1153 | % % |
| 1154 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 1155 | % |
| 1156 | % ScaleResampleFilter() does all the calculations needed to resample an image |
| 1157 | % at a specific scale, defined by two scaling vectors. This not using |
| 1158 | % a orthogonal scaling, but two distorted scaling vectors, to allow the |
| 1159 | % generation of a angled ellipse. |
| 1160 | % |
| 1161 | % As only two deritive scaling vectors are used the center of the ellipse |
| 1162 | % must be the center of the lookup. That is any curvature that the |
| 1163 | % distortion may produce is discounted. |
| 1164 | % |
| 1165 | % The input vectors are produced by either finding the derivitives of the |
| 1166 | % distortion function, or the partial derivitives from a distortion mapping. |
| 1167 | % They do not need to be the orthogonal dx,dy scaling vectors, but can be |
| 1168 | % calculated from other derivatives. For example you could use dr,da/r |
| 1169 | % polar coordinate vector scaling vectors |
| 1170 | % |
| 1171 | % If u,v = DistortEquation(x,y) |
| 1172 | % Then the scaling vectors dx,dy (in u,v space) are the derivitives... |
| 1173 | % du/dx, dv/dx and du/dy, dv/dy |
| 1174 | % If the scaling is only othogonally aligned then... |
| 1175 | % dv/dx = 0 and du/dy = 0 |
| 1176 | % Producing an othogonally alligned ellipse for the area to be resampled. |
| 1177 | % |
| 1178 | % Note that scaling vectors are different to argument order. Argument order |
| 1179 | % is the general order the deritives are extracted from the distortion |
| 1180 | % equations, EG: U(x,y), V(x,y). Caution is advised if you are trying to |
| 1181 | % define the ellipse directly from scaling vectors. |
| 1182 | % |
| 1183 | % The format of the ScaleResampleFilter method is: |
| 1184 | % |
| 1185 | % void ScaleResampleFilter(const ResampleFilter *resample_filter, |
| 1186 | % const double dux,const double duy,const double dvx,const double dvy) |
| 1187 | % |
| 1188 | % A description of each parameter follows: |
| 1189 | % |
| 1190 | % o resample_filter: the resampling resample_filterrmation defining the |
| 1191 | % image being resampled |
| 1192 | % |
| 1193 | % o dux,duy,dvx,dvy: |
| 1194 | % The partial derivitives or scaling vectors for resampling. |
| 1195 | % dx = du/dx, dv/dx and dy = du/dy, dv/dy |
| 1196 | % |
| 1197 | % The values are used to define the size and angle of the |
| 1198 | % elliptical resampling area, centered on the lookup point. |
| 1199 | % |
| 1200 | */ |
| 1201 | MagickExport void ScaleResampleFilter(ResampleFilter *resample_filter, |
| 1202 | const double dux,const double duy,const double dvx,const double dvy) |
| 1203 | { |
| 1204 | double A,B,C,F, area; |
| 1205 | |
| 1206 | assert(resample_filter != (ResampleFilter *) NULL); |
| 1207 | assert(resample_filter->signature == MagickSignature); |
| 1208 | |
| 1209 | resample_filter->limit_reached = MagickFalse; |
| 1210 | resample_filter->do_interpolate = MagickFalse; |
| 1211 | |
| 1212 | /* A 'point' filter forces use of interpolation instead of area sampling */ |
| 1213 | if ( resample_filter->filter == PointFilter ) { |
| 1214 | resample_filter->do_interpolate = MagickTrue; |
| 1215 | return; |
| 1216 | } |
| 1217 | |
| 1218 | /* Find Ellipse Coefficents such that |
| 1219 | A*u^2 + B*u*v + C*v^2 = F |
| 1220 | With u,v relative to point around which we are resampling. |
| 1221 | And the given scaling dx,dy vectors in u,v space |
| 1222 | du/dx,dv/dx and du/dy,dv/dy |
| 1223 | */ |
| 1224 | #if 0 |
| 1225 | /* Direct conversions of derivatives to elliptical coefficients |
| 1226 | No scaling will result in F == 1.0 and a unit circle. |
| 1227 | */ |
| 1228 | A = dvx*dvx+dvy*dvy; |
| 1229 | B = (dux*dvx+duy*dvy)*-2.0; |
| 1230 | C = dux*dux+duy*duy; |
| 1231 | F = dux*dvy+duy*dvx; |
| 1232 | F *= F; |
| 1233 | #define F_UNITY 1.0 |
| 1234 | #else |
| 1235 | /* This Paul Heckbert's recomended "Higher Quality EWA" formula, from page |
| 1236 | 60 in his thesis, which adds a unit circle to the elliptical area so are |
| 1237 | to do both Reconstruction and Prefiltering of the pixels in the |
| 1238 | resampling. It also means it is likely to have at least 4 pixels within |
| 1239 | the area of the ellipse, for weighted averaging. |
| 1240 | No scaling will result if F == 4.0 and a circle of radius 2.0 |
| 1241 | */ |
| 1242 | A = dvx*dvx+dvy*dvy+1; |
| 1243 | B = (dux*dvx+duy*dvy)*-2.0; |
| 1244 | C = dux*dux+duy*duy+1; |
| 1245 | F = A*C - B*B/4; |
| 1246 | #define F_UNITY 4.0 |
| 1247 | #endif |
| 1248 | |
| 1249 | /* DEBUGGING OUTPUT */ |
| 1250 | #if 0 |
| 1251 | fprintf(stderr, "dux=%lf; dvx=%lf; duy=%lf; dvy%lf;\n", |
| 1252 | dux, dvx, duy, dvy); |
| 1253 | fprintf(stderr, "A=%lf; B=%lf; C=%lf; F=%lf\n", A,B,C,F); |
| 1254 | #endif |
| 1255 | |
| 1256 | #if 0 |
| 1257 | /* Figure out the Ellipses Major and Minor Axis, and other info. |
| 1258 | This information currently not needed at this time, but may be |
| 1259 | needed later for better limit determination. |
| 1260 | */ |
| 1261 | { double alpha, beta, gamma, Major, Minor; |
| 1262 | double Eccentricity, Ellipse_Area, Ellipse_angle; |
| 1263 | double max_horizontal_cross_section, max_vertical_cross_section; |
| 1264 | alpha = A+C; |
| 1265 | beta = A-C; |
| 1266 | gamma = sqrt(beta*beta + B*B ); |
| 1267 | |
| 1268 | if ( alpha - gamma <= MagickEpsilon ) |
| 1269 | Major = MagickHuge; |
| 1270 | else |
| 1271 | Major = sqrt(2*F/(alpha - gamma)); |
| 1272 | Minor = sqrt(2*F/(alpha + gamma)); |
| 1273 | |
| 1274 | fprintf(stderr, "\tMajor=%lf; Minor=%lf\n", |
| 1275 | Major, Minor ); |
| 1276 | |
| 1277 | /* other information about ellipse include... */ |
| 1278 | Eccentricity = Major/Minor; |
| 1279 | Ellipse_Area = MagickPI*Major*Minor; |
| 1280 | Ellipse_angle = atan2(B, A-C); |
| 1281 | |
| 1282 | fprintf(stderr, "\tAngle=%lf Area=%lf\n", |
| 1283 | RadiansToDegrees(Ellipse_angle), Ellipse_Area ); |
| 1284 | |
| 1285 | /* Ellipse limits */ |
| 1286 | |
| 1287 | /* orthogonal rectangle - improved ellipse */ |
| 1288 | max_horizontal_orthogonal = sqrt(A); /* = sqrt(4*A*F/(4*A*C-B*B)) */ |
| 1289 | max_vertical_orthogonal = sqrt(C); /* = sqrt(4*C*F/(4*A*C-B*B)) */ |
| 1290 | |
| 1291 | /* parallelogram bounds -- what we are using */ |
| 1292 | max_horizontal_cross_section = sqrt(F/A); |
| 1293 | max_vertical_cross_section = sqrt(F/C); |
| 1294 | } |
| 1295 | #endif |
| 1296 | |
| 1297 | /* Is default elliptical area, too small? Image being magnified? |
| 1298 | Switch to doing pure 'point' interpolation of the pixel. |
| 1299 | That is turn off EWA Resampling. |
| 1300 | */ |
| 1301 | if ( F <= F_UNITY ) { |
| 1302 | resample_filter->do_interpolate = MagickTrue; |
| 1303 | return; |
| 1304 | } |
| 1305 | |
| 1306 | |
| 1307 | /* If F is impossibly large, we may as well not bother doing any |
| 1308 | * form of resampling, as you risk an infinite resampled area. |
| 1309 | */ |
| 1310 | if ( F > MagickHuge ) { |
| 1311 | resample_filter->limit_reached = MagickTrue; |
| 1312 | return; |
| 1313 | } |
| 1314 | |
| 1315 | /* Othogonal bounds of the ellipse */ |
| 1316 | resample_filter->sqrtA = sqrt(A)+1.0; /* Vertical Orthogonal Limit */ |
| 1317 | resample_filter->sqrtC = sqrt(C)+1.0; /* Horizontal Orthogonal Limit */ |
| 1318 | |
| 1319 | /* Horizontally aligned Parallelogram fitted to ellipse */ |
| 1320 | resample_filter->sqrtU = sqrt(F/A)+1.0; /* Parallelogram Width */ |
| 1321 | resample_filter->slope = -B/(2*A); /* Slope of the parallelogram */ |
| 1322 | |
| 1323 | /* The size of the area of the parallelogram we will be sampling */ |
| 1324 | area = 4 * resample_filter->sqrtA * resample_filter->sqrtU; |
| 1325 | |
| 1326 | /* Absolute limit on the area to be resampled |
| 1327 | * This limit needs more work, as it gets too slow for |
| 1328 | * larger images involved with tiled views of the horizon. */ |
| 1329 | if ( area > 20.0*resample_filter->image_area ) { |
| 1330 | resample_filter->limit_reached = MagickTrue; |
| 1331 | return; |
| 1332 | } |
| 1333 | |
| 1334 | /* Scale ellipse formula to directly fit the Filter Lookup Table */ |
| 1335 | { register double scale; |
| 1336 | scale = (double)WLUT_WIDTH/F; |
| 1337 | resample_filter->A = A*scale; |
| 1338 | resample_filter->B = B*scale; |
| 1339 | resample_filter->C = C*scale; |
| 1340 | /* ..ple_filter->F = WLUT_WIDTH; -- hardcoded */ |
| 1341 | } |
| 1342 | } |
| 1343 | |
| 1344 | /* |
| 1345 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 1346 | % % |
| 1347 | % % |
| 1348 | % % |
| 1349 | % S e t R e s a m p l e F i l t e r % |
| 1350 | % % |
| 1351 | % % |
| 1352 | % % |
| 1353 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 1354 | % |
| 1355 | % SetResampleFilter() set the resampling filter lookup table based on a |
| 1356 | % specific filter. Note that the filter is used as a radial filter not as a |
| 1357 | % two pass othogonally aligned resampling filter. |
| 1358 | % |
| 1359 | % The default Filter, is Gaussian, which is the standard filter used by the |
| 1360 | % original paper on the Elliptical Weighted Everage Algorithm. However other |
| 1361 | % filters can also be used. |
| 1362 | % |
| 1363 | % The format of the SetResampleFilter method is: |
| 1364 | % |
| 1365 | % void SetResampleFilter(ResampleFilter *resample_filter, |
| 1366 | % const FilterTypes filter,const double blur) |
| 1367 | % |
| 1368 | % A description of each parameter follows: |
| 1369 | % |
| 1370 | % o resample_filter: resampling resample_filterrmation structure |
| 1371 | % |
| 1372 | % o filter: the resize filter for elliptical weighting LUT |
| 1373 | % |
| 1374 | % o blur: filter blur factor (radial scaling) for elliptical weighting LUT |
| 1375 | % |
| 1376 | */ |
| 1377 | MagickExport void SetResampleFilter(ResampleFilter *resample_filter, |
| 1378 | const FilterTypes filter,const double blur) |
| 1379 | { |
| 1380 | register int |
| 1381 | Q; |
| 1382 | |
| 1383 | double |
| 1384 | r_scale; |
| 1385 | |
| 1386 | ResizeFilter |
| 1387 | *resize_filter; |
| 1388 | |
| 1389 | assert(resample_filter != (ResampleFilter *) NULL); |
| 1390 | assert(resample_filter->signature == MagickSignature); |
| 1391 | |
| 1392 | resample_filter->filter = filter; |
| 1393 | |
| 1394 | /* Scale radius so it equals 1.0, at edge of ellipse when a |
| 1395 | default blurring factor of 1.0 is used. |
| 1396 | |
| 1397 | Note that these filters are being used as a radial filter, not as |
| 1398 | an othoginally alligned filter. How this effects results is still |
| 1399 | being worked out. |
| 1400 | |
| 1401 | Future: Direct use of teh resize filters in "resize.c" to set the lookup |
| 1402 | table, based on the filters working support window. |
| 1403 | */ |
| 1404 | r_scale = sqrt(1.0/(double)WLUT_WIDTH)/blur; |
| 1405 | r_scale *= 2; /* for 2 pixel radius of Improved Elliptical Formula */ |
| 1406 | |
| 1407 | switch ( filter ) { |
| 1408 | case PointFilter: |
| 1409 | /* This equivelent to turning off the EWA algroithm. |
| 1410 | Only Interpolated lookup will be used. */ |
| 1411 | break; |
| 1412 | default: |
| 1413 | /* |
| 1414 | Fill the LUT with a 1D resize filter function |
| 1415 | But make the Sinc/Bessel tapered window 2.0 |
| 1416 | I also normalize the result so the filter is 1.0 |
| 1417 | */ |
| 1418 | resize_filter = AcquireResizeFilter(resample_filter->image,filter, |
| 1419 | (MagickRealType)1.0,MagickTrue,resample_filter->exception); |
| 1420 | if (resize_filter != (ResizeFilter *) NULL) { |
| 1421 | resample_filter->support = GetResizeFilterSupport(resize_filter); |
| 1422 | resample_filter->support /= blur; /* taken into account above */ |
| 1423 | resample_filter->support *= resample_filter->support; |
| 1424 | resample_filter->support *= (double)WLUT_WIDTH/4; |
| 1425 | if ( resample_filter->support >= (double)WLUT_WIDTH ) |
| 1426 | resample_filter->support = (double)WLUT_WIDTH; /* hack */ |
| 1427 | for(Q=0; Q<WLUT_WIDTH; Q++) |
| 1428 | if ( (double) Q < resample_filter->support ) |
| 1429 | resample_filter->filter_lut[Q] = (double) |
| 1430 | GetResizeFilterWeight(resize_filter,sqrt((double)Q)*r_scale); |
| 1431 | else |
| 1432 | resample_filter->filter_lut[Q] = 0.0; |
| 1433 | resize_filter = DestroyResizeFilter(resize_filter); |
| 1434 | break; |
| 1435 | } |
| 1436 | else { |
| 1437 | (void) ThrowMagickException(resample_filter->exception,GetMagickModule(), |
| 1438 | ModuleError, "UnableToSetFilteringValue", |
| 1439 | "Fall back to default EWA gaussian filter"); |
| 1440 | } |
| 1441 | /* FALLTHRU - on exception */ |
| 1442 | /*case GaussianFilter:*/ |
| 1443 | case UndefinedFilter: |
| 1444 | /* |
| 1445 | Create Normal Gaussian 2D Filter Weighted Lookup Table. |
| 1446 | A normal EWA guassual lookup would use exp(Q*ALPHA) |
| 1447 | where Q = distantce squared from 0.0 (center) to 1.0 (edge) |
| 1448 | and ALPHA = -4.0*ln(2.0) ==> -2.77258872223978123767 |
| 1449 | However the table is of length 1024, and equates to a radius of 2px |
| 1450 | thus needs to be scaled by ALPHA*4/1024 and any blur factor squared |
| 1451 | */ |
| 1452 | /*r_scale = -2.77258872223978123767*4/WLUT_WIDTH/blur/blur;*/ |
| 1453 | r_scale = -2.77258872223978123767/WLUT_WIDTH/blur/blur; |
| 1454 | for(Q=0; Q<WLUT_WIDTH; Q++) |
| 1455 | resample_filter->filter_lut[Q] = exp((double)Q*r_scale); |
| 1456 | resample_filter->support = WLUT_WIDTH; |
| 1457 | break; |
| 1458 | } |
| 1459 | if (GetImageArtifact(resample_filter->image,"resample:verbose") |
| 1460 | != (const char *) NULL) |
| 1461 | /* Debug output of the filter weighting LUT |
| 1462 | Gnuplot the LUT with hoizontal adjusted to 'r' using... |
| 1463 | plot [0:2][-.2:1] "lut.dat" using (sqrt($0/1024)*2):1 with lines |
| 1464 | THe filter values is normalized for comparision |
| 1465 | */ |
| 1466 | for(Q=0; Q<WLUT_WIDTH; Q++) |
| 1467 | printf("%lf\n", resample_filter->filter_lut[Q] |
| 1468 | /resample_filter->filter_lut[0] ); |
| 1469 | return; |
| 1470 | } |
| 1471 | |
| 1472 | /* |
| 1473 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 1474 | % % |
| 1475 | % % |
| 1476 | % % |
| 1477 | % S e t R e s a m p l e F i l t e r I n t e r p o l a t e M e t h o d % |
| 1478 | % % |
| 1479 | % % |
| 1480 | % % |
| 1481 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 1482 | % |
| 1483 | % SetResampleFilterInterpolateMethod() changes the interpolation method |
| 1484 | % associated with the specified resample filter. |
| 1485 | % |
| 1486 | % The format of the SetResampleFilterInterpolateMethod method is: |
| 1487 | % |
| 1488 | % MagickBooleanType SetResampleFilterInterpolateMethod( |
| 1489 | % ResampleFilter *resample_filter,const InterpolateMethod method) |
| 1490 | % |
| 1491 | % A description of each parameter follows: |
| 1492 | % |
| 1493 | % o resample_filter: the resample filter. |
| 1494 | % |
| 1495 | % o method: the interpolation method. |
| 1496 | % |
| 1497 | */ |
| 1498 | MagickExport MagickBooleanType SetResampleFilterInterpolateMethod( |
| 1499 | ResampleFilter *resample_filter,const InterpolatePixelMethod method) |
| 1500 | { |
| 1501 | assert(resample_filter != (ResampleFilter *) NULL); |
| 1502 | assert(resample_filter->signature == MagickSignature); |
| 1503 | assert(resample_filter->image != (Image *) NULL); |
| 1504 | if (resample_filter->debug != MagickFalse) |
| 1505 | (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s", |
| 1506 | resample_filter->image->filename); |
| 1507 | resample_filter->interpolate=method; |
| 1508 | return(MagickTrue); |
| 1509 | } |
| 1510 | |
| 1511 | /* |
| 1512 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 1513 | % % |
| 1514 | % % |
| 1515 | % % |
| 1516 | % S e t R e s a m p l e F i l t e r V i r t u a l P i x e l M e t h o d % |
| 1517 | % % |
| 1518 | % % |
| 1519 | % % |
| 1520 | %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
| 1521 | % |
| 1522 | % SetResampleFilterVirtualPixelMethod() changes the virtual pixel method |
| 1523 | % associated with the specified resample filter. |
| 1524 | % |
| 1525 | % The format of the SetResampleFilterVirtualPixelMethod method is: |
| 1526 | % |
| 1527 | % MagickBooleanType SetResampleFilterVirtualPixelMethod( |
| 1528 | % ResampleFilter *resample_filter,const VirtualPixelMethod method) |
| 1529 | % |
| 1530 | % A description of each parameter follows: |
| 1531 | % |
| 1532 | % o resample_filter: the resample filter. |
| 1533 | % |
| 1534 | % o method: the virtual pixel method. |
| 1535 | % |
| 1536 | */ |
| 1537 | MagickExport MagickBooleanType SetResampleFilterVirtualPixelMethod( |
| 1538 | ResampleFilter *resample_filter,const VirtualPixelMethod method) |
| 1539 | { |
| 1540 | assert(resample_filter != (ResampleFilter *) NULL); |
| 1541 | assert(resample_filter->signature == MagickSignature); |
| 1542 | assert(resample_filter->image != (Image *) NULL); |
| 1543 | if (resample_filter->debug != MagickFalse) |
| 1544 | (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s", |
| 1545 | resample_filter->image->filename); |
| 1546 | resample_filter->virtual_pixel=method; |
| 1547 | (void) SetCacheViewVirtualPixelMethod(resample_filter->view,method); |
| 1548 | return(MagickTrue); |
| 1549 | } |