| 1 | |
| 2 | /* pngrtran.c - transforms the data in a row for PNG readers |
| 3 | * |
| 4 | * libpng 1.0.3 - January 14, 1999 |
| 5 | * For conditions of distribution and use, see copyright notice in png.h |
| 6 | * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| 7 | * Copyright (c) 1996, 1997 Andreas Dilger |
| 8 | * Copyright (c) 1998, 1999 Glenn Randers-Pehrson |
| 9 | * |
| 10 | * This file contains functions optionally called by an application |
| 11 | * in order to tell libpng how to handle data when reading a PNG. |
| 12 | * Transformations that are used in both reading and writing are |
| 13 | * in pngtrans.c. |
| 14 | */ |
| 15 | |
| 16 | #define PNG_INTERNAL |
| 17 | #include "png.h" |
| 18 | |
| 19 | #if defined(_MSC_VER) && !defined(__MWERKS__) |
| 20 | #define __VISUALC__ _MSC_VER |
| 21 | #endif |
| 22 | #ifdef __VISUALC__ |
| 23 | #ifndef WIN32 |
| 24 | #pragma warning(disable:4135) |
| 25 | #endif |
| 26 | #endif |
| 27 | |
| 28 | /* Set the action on getting a CRC error for an ancillary or critical chunk. */ |
| 29 | void |
| 30 | png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) |
| 31 | { |
| 32 | png_debug(1, "in png_set_crc_action\n"); |
| 33 | /* Tell libpng how we react to CRC errors in critical chunks */ |
| 34 | switch (crit_action) |
| 35 | { |
| 36 | case PNG_CRC_NO_CHANGE: /* leave setting as is */ |
| 37 | break; |
| 38 | case PNG_CRC_WARN_USE: /* warn/use data */ |
| 39 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
| 40 | png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; |
| 41 | break; |
| 42 | case PNG_CRC_QUIET_USE: /* quiet/use data */ |
| 43 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
| 44 | png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | |
| 45 | PNG_FLAG_CRC_CRITICAL_IGNORE; |
| 46 | break; |
| 47 | case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */ |
| 48 | png_warning(png_ptr, "Can't discard critical data on CRC error."); |
| 49 | case PNG_CRC_ERROR_QUIT: /* error/quit */ |
| 50 | case PNG_CRC_DEFAULT: |
| 51 | default: |
| 52 | png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
| 53 | break; |
| 54 | } |
| 55 | |
| 56 | switch (ancil_action) |
| 57 | { |
| 58 | case PNG_CRC_NO_CHANGE: /* leave setting as is */ |
| 59 | break; |
| 60 | case PNG_CRC_WARN_USE: /* warn/use data */ |
| 61 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
| 62 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; |
| 63 | break; |
| 64 | case PNG_CRC_QUIET_USE: /* quiet/use data */ |
| 65 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
| 66 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | |
| 67 | PNG_FLAG_CRC_ANCILLARY_NOWARN; |
| 68 | break; |
| 69 | case PNG_CRC_ERROR_QUIT: /* error/quit */ |
| 70 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
| 71 | png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; |
| 72 | break; |
| 73 | case PNG_CRC_WARN_DISCARD: /* warn/discard data */ |
| 74 | case PNG_CRC_DEFAULT: |
| 75 | default: |
| 76 | png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
| 77 | break; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 82 | /* handle alpha and tRNS via a background color */ |
| 83 | void |
| 84 | png_set_background(png_structp png_ptr, |
| 85 | png_color_16p background_color, int background_gamma_code, |
| 86 | int need_expand, double background_gamma) |
| 87 | { |
| 88 | png_debug(1, "in png_set_background\n"); |
| 89 | if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) |
| 90 | { |
| 91 | png_warning(png_ptr, "Application must supply a known background gamma"); |
| 92 | return; |
| 93 | } |
| 94 | |
| 95 | png_ptr->transformations |= PNG_BACKGROUND; |
| 96 | png_memcpy(&(png_ptr->background), background_color, sizeof(png_color_16)); |
| 97 | png_ptr->background_gamma = (float)background_gamma; |
| 98 | png_ptr->background_gamma_type = (png_byte)(background_gamma_code); |
| 99 | png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); |
| 100 | |
| 101 | /* Note: if need_expand is set and color_type is either RGB or RGB_ALPHA |
| 102 | * (in which case need_expand is superfluous anyway), the background color |
| 103 | * might actually be gray yet not be flagged as such. This is not a problem |
| 104 | * for the current code, which uses PNG_FLAG_BACKGROUND_IS_GRAY only to |
| 105 | * decide when to do the png_do_gray_to_rgb() transformation. |
| 106 | */ |
| 107 | if ((need_expand && !(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) || |
| 108 | (!need_expand && background_color->red == background_color->green && |
| 109 | background_color->red == background_color->blue)) |
| 110 | png_ptr->flags |= PNG_FLAG_BACKGROUND_IS_GRAY; |
| 111 | } |
| 112 | #endif |
| 113 | |
| 114 | #if defined(PNG_READ_16_TO_8_SUPPORTED) |
| 115 | /* strip 16 bit depth files to 8 bit depth */ |
| 116 | void |
| 117 | png_set_strip_16(png_structp png_ptr) |
| 118 | { |
| 119 | png_debug(1, "in png_set_strip_16\n"); |
| 120 | png_ptr->transformations |= PNG_16_TO_8; |
| 121 | } |
| 122 | #endif |
| 123 | |
| 124 | #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
| 125 | void |
| 126 | png_set_strip_alpha(png_structp png_ptr) |
| 127 | { |
| 128 | png_debug(1, "in png_set_strip_alpha\n"); |
| 129 | png_ptr->transformations |= PNG_STRIP_ALPHA; |
| 130 | } |
| 131 | #endif |
| 132 | |
| 133 | #if defined(PNG_READ_DITHER_SUPPORTED) |
| 134 | /* Dither file to 8 bit. Supply a palette, the current number |
| 135 | * of elements in the palette, the maximum number of elements |
| 136 | * allowed, and a histogram if possible. If the current number |
| 137 | * of colors is greater then the maximum number, the palette will be |
| 138 | * modified to fit in the maximum number. "full_dither" indicates |
| 139 | * whether we need a dithering cube set up for RGB images, or if we |
| 140 | * simply are reducing the number of colors in a paletted image. |
| 141 | */ |
| 142 | |
| 143 | typedef struct png_dsort_struct |
| 144 | { |
| 145 | struct png_dsort_struct FAR * next; |
| 146 | png_byte left; |
| 147 | png_byte right; |
| 148 | } png_dsort; |
| 149 | typedef png_dsort FAR * png_dsortp; |
| 150 | typedef png_dsort FAR * FAR * png_dsortpp; |
| 151 | |
| 152 | void |
| 153 | png_set_dither(png_structp png_ptr, png_colorp palette, |
| 154 | int num_palette, int maximum_colors, png_uint_16p histogram, |
| 155 | int full_dither) |
| 156 | { |
| 157 | png_debug(1, "in png_set_dither\n"); |
| 158 | png_ptr->transformations |= PNG_DITHER; |
| 159 | |
| 160 | if (!full_dither) |
| 161 | { |
| 162 | int i; |
| 163 | |
| 164 | png_ptr->dither_index = (png_bytep)png_malloc(png_ptr, |
| 165 | (png_uint_32)(num_palette * sizeof (png_byte))); |
| 166 | for (i = 0; i < num_palette; i++) |
| 167 | png_ptr->dither_index[i] = (png_byte)i; |
| 168 | } |
| 169 | |
| 170 | if (num_palette > maximum_colors) |
| 171 | { |
| 172 | if (histogram != NULL) |
| 173 | { |
| 174 | /* This is easy enough, just throw out the least used colors. |
| 175 | Perhaps not the best solution, but good enough. */ |
| 176 | |
| 177 | int i; |
| 178 | png_bytep sort; |
| 179 | |
| 180 | /* initialize an array to sort colors */ |
| 181 | sort = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_palette |
| 182 | * sizeof (png_byte))); |
| 183 | |
| 184 | /* initialize the sort array */ |
| 185 | for (i = 0; i < num_palette; i++) |
| 186 | sort[i] = (png_byte)i; |
| 187 | |
| 188 | /* Find the least used palette entries by starting a |
| 189 | bubble sort, and running it until we have sorted |
| 190 | out enough colors. Note that we don't care about |
| 191 | sorting all the colors, just finding which are |
| 192 | least used. */ |
| 193 | |
| 194 | for (i = num_palette - 1; i >= maximum_colors; i--) |
| 195 | { |
| 196 | int done; /* to stop early if the list is pre-sorted */ |
| 197 | int j; |
| 198 | |
| 199 | done = 1; |
| 200 | for (j = 0; j < i; j++) |
| 201 | { |
| 202 | if (histogram[sort[j]] < histogram[sort[j + 1]]) |
| 203 | { |
| 204 | png_byte t; |
| 205 | |
| 206 | t = sort[j]; |
| 207 | sort[j] = sort[j + 1]; |
| 208 | sort[j + 1] = t; |
| 209 | done = 0; |
| 210 | } |
| 211 | } |
| 212 | if (done) |
| 213 | break; |
| 214 | } |
| 215 | |
| 216 | /* swap the palette around, and set up a table, if necessary */ |
| 217 | if (full_dither) |
| 218 | { |
| 219 | int j = num_palette; |
| 220 | |
| 221 | /* put all the useful colors within the max, but don't |
| 222 | move the others */ |
| 223 | for (i = 0; i < maximum_colors; i++) |
| 224 | { |
| 225 | if ((int)sort[i] >= maximum_colors) |
| 226 | { |
| 227 | do |
| 228 | j--; |
| 229 | while ((int)sort[j] >= maximum_colors); |
| 230 | palette[i] = palette[j]; |
| 231 | } |
| 232 | } |
| 233 | } |
| 234 | else |
| 235 | { |
| 236 | int j = num_palette; |
| 237 | |
| 238 | /* move all the used colors inside the max limit, and |
| 239 | develop a translation table */ |
| 240 | for (i = 0; i < maximum_colors; i++) |
| 241 | { |
| 242 | /* only move the colors we need to */ |
| 243 | if ((int)sort[i] >= maximum_colors) |
| 244 | { |
| 245 | png_color tmp_color; |
| 246 | |
| 247 | do |
| 248 | j--; |
| 249 | while ((int)sort[j] >= maximum_colors); |
| 250 | |
| 251 | tmp_color = palette[j]; |
| 252 | palette[j] = palette[i]; |
| 253 | palette[i] = tmp_color; |
| 254 | /* indicate where the color went */ |
| 255 | png_ptr->dither_index[j] = (png_byte)i; |
| 256 | png_ptr->dither_index[i] = (png_byte)j; |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | /* find closest color for those colors we are not using */ |
| 261 | for (i = 0; i < num_palette; i++) |
| 262 | { |
| 263 | if ((int)png_ptr->dither_index[i] >= maximum_colors) |
| 264 | { |
| 265 | int min_d, k, min_k, d_index; |
| 266 | |
| 267 | /* find the closest color to one we threw out */ |
| 268 | d_index = png_ptr->dither_index[i]; |
| 269 | min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); |
| 270 | for (k = 1, min_k = 0; k < maximum_colors; k++) |
| 271 | { |
| 272 | int d; |
| 273 | |
| 274 | d = PNG_COLOR_DIST(palette[d_index], palette[k]); |
| 275 | |
| 276 | if (d < min_d) |
| 277 | { |
| 278 | min_d = d; |
| 279 | min_k = k; |
| 280 | } |
| 281 | } |
| 282 | /* point to closest color */ |
| 283 | png_ptr->dither_index[i] = (png_byte)min_k; |
| 284 | } |
| 285 | } |
| 286 | } |
| 287 | png_free(png_ptr, sort); |
| 288 | } |
| 289 | else |
| 290 | { |
| 291 | /* This is much harder to do simply (and quickly). Perhaps |
| 292 | we need to go through a median cut routine, but those |
| 293 | don't always behave themselves with only a few colors |
| 294 | as input. So we will just find the closest two colors, |
| 295 | and throw out one of them (chosen somewhat randomly). |
| 296 | [We don't understand this at all, so if someone wants to |
| 297 | work on improving it, be our guest - AED, GRP] |
| 298 | */ |
| 299 | int i; |
| 300 | int max_d; |
| 301 | int num_new_palette; |
| 302 | png_dsortpp hash; |
| 303 | png_bytep index_to_palette; |
| 304 | /* where the original index currently is in the palette */ |
| 305 | png_bytep palette_to_index; |
| 306 | /* which original index points to this palette color */ |
| 307 | |
| 308 | /* initialize palette index arrays */ |
| 309 | index_to_palette = (png_bytep)png_malloc(png_ptr, |
| 310 | (png_uint_32)(num_palette * sizeof (png_byte))); |
| 311 | palette_to_index = (png_bytep)png_malloc(png_ptr, |
| 312 | (png_uint_32)(num_palette * sizeof (png_byte))); |
| 313 | |
| 314 | /* initialize the sort array */ |
| 315 | for (i = 0; i < num_palette; i++) |
| 316 | { |
| 317 | index_to_palette[i] = (png_byte)i; |
| 318 | palette_to_index[i] = (png_byte)i; |
| 319 | } |
| 320 | |
| 321 | hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * |
| 322 | sizeof (png_dsortp))); |
| 323 | for (i = 0; i < 769; i++) |
| 324 | hash[i] = NULL; |
| 325 | /* png_memset(hash, 0, 769 * sizeof (png_dsortp)); */ |
| 326 | |
| 327 | num_new_palette = num_palette; |
| 328 | |
| 329 | /* initial wild guess at how far apart the farthest pixel |
| 330 | pair we will be eliminating will be. Larger |
| 331 | numbers mean more areas will be allocated, Smaller |
| 332 | numbers run the risk of not saving enough data, and |
| 333 | having to do this all over again. |
| 334 | |
| 335 | I have not done extensive checking on this number. |
| 336 | */ |
| 337 | max_d = 96; |
| 338 | |
| 339 | while (num_new_palette > maximum_colors) |
| 340 | { |
| 341 | for (i = 0; i < num_new_palette - 1; i++) |
| 342 | { |
| 343 | int j; |
| 344 | |
| 345 | for (j = i + 1; j < num_new_palette; j++) |
| 346 | { |
| 347 | int d; |
| 348 | |
| 349 | d = PNG_COLOR_DIST(palette[i], palette[j]); |
| 350 | |
| 351 | if (d <= max_d) |
| 352 | { |
| 353 | png_dsortp t; |
| 354 | |
| 355 | t = (png_dsortp)png_malloc(png_ptr, (png_uint_32)(sizeof |
| 356 | (png_dsort))); |
| 357 | t->next = hash[d]; |
| 358 | t->left = (png_byte)i; |
| 359 | t->right = (png_byte)j; |
| 360 | hash[d] = t; |
| 361 | } |
| 362 | } |
| 363 | } |
| 364 | |
| 365 | for (i = 0; i <= max_d; i++) |
| 366 | { |
| 367 | if (hash[i] != NULL) |
| 368 | { |
| 369 | png_dsortp p; |
| 370 | |
| 371 | for (p = hash[i]; p; p = p->next) |
| 372 | { |
| 373 | if ((int)index_to_palette[p->left] < num_new_palette && |
| 374 | (int)index_to_palette[p->right] < num_new_palette) |
| 375 | { |
| 376 | int j, next_j; |
| 377 | |
| 378 | if (num_new_palette & 1) |
| 379 | { |
| 380 | j = p->left; |
| 381 | next_j = p->right; |
| 382 | } |
| 383 | else |
| 384 | { |
| 385 | j = p->right; |
| 386 | next_j = p->left; |
| 387 | } |
| 388 | |
| 389 | num_new_palette--; |
| 390 | palette[index_to_palette[j]] = palette[num_new_palette]; |
| 391 | if (!full_dither) |
| 392 | { |
| 393 | int k; |
| 394 | |
| 395 | for (k = 0; k < num_palette; k++) |
| 396 | { |
| 397 | if (png_ptr->dither_index[k] == |
| 398 | index_to_palette[j]) |
| 399 | png_ptr->dither_index[k] = |
| 400 | index_to_palette[next_j]; |
| 401 | if ((int)png_ptr->dither_index[k] == |
| 402 | num_new_palette) |
| 403 | png_ptr->dither_index[k] = |
| 404 | index_to_palette[j]; |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | index_to_palette[palette_to_index[num_new_palette]] = |
| 409 | index_to_palette[j]; |
| 410 | palette_to_index[index_to_palette[j]] = |
| 411 | palette_to_index[num_new_palette]; |
| 412 | |
| 413 | index_to_palette[j] = (png_byte)num_new_palette; |
| 414 | palette_to_index[num_new_palette] = (png_byte)j; |
| 415 | } |
| 416 | if (num_new_palette <= maximum_colors) |
| 417 | break; |
| 418 | } |
| 419 | if (num_new_palette <= maximum_colors) |
| 420 | break; |
| 421 | } |
| 422 | } |
| 423 | |
| 424 | for (i = 0; i < 769; i++) |
| 425 | { |
| 426 | if (hash[i] != NULL) |
| 427 | { |
| 428 | png_dsortp p = hash[i]; |
| 429 | while (p) |
| 430 | { |
| 431 | png_dsortp t; |
| 432 | |
| 433 | t = p->next; |
| 434 | png_free(png_ptr, p); |
| 435 | p = t; |
| 436 | } |
| 437 | } |
| 438 | hash[i] = 0; |
| 439 | } |
| 440 | max_d += 96; |
| 441 | } |
| 442 | png_free(png_ptr, hash); |
| 443 | png_free(png_ptr, palette_to_index); |
| 444 | png_free(png_ptr, index_to_palette); |
| 445 | } |
| 446 | num_palette = maximum_colors; |
| 447 | } |
| 448 | if (png_ptr->palette == NULL) |
| 449 | { |
| 450 | png_ptr->palette = palette; |
| 451 | } |
| 452 | png_ptr->num_palette = (png_uint_16)num_palette; |
| 453 | |
| 454 | if (full_dither) |
| 455 | { |
| 456 | int i; |
| 457 | png_bytep distance; |
| 458 | int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS + |
| 459 | PNG_DITHER_BLUE_BITS; |
| 460 | int num_red = (1 << PNG_DITHER_RED_BITS); |
| 461 | int num_green = (1 << PNG_DITHER_GREEN_BITS); |
| 462 | int num_blue = (1 << PNG_DITHER_BLUE_BITS); |
| 463 | png_size_t num_entries = ((png_size_t)1 << total_bits); |
| 464 | |
| 465 | png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr, |
| 466 | (png_uint_32)(num_entries * sizeof (png_byte))); |
| 467 | |
| 468 | png_memset(png_ptr->palette_lookup, 0, num_entries * sizeof (png_byte)); |
| 469 | |
| 470 | distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * |
| 471 | sizeof(png_byte))); |
| 472 | |
| 473 | png_memset(distance, 0xff, num_entries * sizeof(png_byte)); |
| 474 | |
| 475 | for (i = 0; i < num_palette; i++) |
| 476 | { |
| 477 | int ir, ig, ib; |
| 478 | int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS)); |
| 479 | int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS)); |
| 480 | int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS)); |
| 481 | |
| 482 | for (ir = 0; ir < num_red; ir++) |
| 483 | { |
| 484 | int dr = abs(ir - r); |
| 485 | int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS)); |
| 486 | |
| 487 | for (ig = 0; ig < num_green; ig++) |
| 488 | { |
| 489 | int dg = abs(ig - g); |
| 490 | int dt = dr + dg; |
| 491 | int dm = ((dr > dg) ? dr : dg); |
| 492 | int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS); |
| 493 | |
| 494 | for (ib = 0; ib < num_blue; ib++) |
| 495 | { |
| 496 | int d_index = index_g | ib; |
| 497 | int db = abs(ib - b); |
| 498 | int dmax = ((dm > db) ? dm : db); |
| 499 | int d = dmax + dt + db; |
| 500 | |
| 501 | if (d < (int)distance[d_index]) |
| 502 | { |
| 503 | distance[d_index] = (png_byte)d; |
| 504 | png_ptr->palette_lookup[d_index] = (png_byte)i; |
| 505 | } |
| 506 | } |
| 507 | } |
| 508 | } |
| 509 | } |
| 510 | |
| 511 | png_free(png_ptr, distance); |
| 512 | } |
| 513 | } |
| 514 | #endif |
| 515 | |
| 516 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 517 | /* Transform the image from the file_gamma to the screen_gamma. We |
| 518 | * only do transformations on images where the file_gamma and screen_gamma |
| 519 | * are not close reciprocals, otherwise it slows things down slightly, and |
| 520 | * also needlessly introduces small errors. |
| 521 | */ |
| 522 | void |
| 523 | png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) |
| 524 | { |
| 525 | png_debug(1, "in png_set_gamma\n"); |
| 526 | if (fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) |
| 527 | png_ptr->transformations |= PNG_GAMMA; |
| 528 | png_ptr->gamma = (float)file_gamma; |
| 529 | png_ptr->screen_gamma = (float)scrn_gamma; |
| 530 | } |
| 531 | #endif |
| 532 | |
| 533 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
| 534 | /* Expand paletted images to rgb, expand grayscale images of |
| 535 | * less than 8 bit depth to 8 bit depth, and expand tRNS chunks |
| 536 | * to alpha channels. |
| 537 | */ |
| 538 | void |
| 539 | png_set_expand(png_structp png_ptr) |
| 540 | { |
| 541 | png_debug(1, "in png_set_expand\n"); |
| 542 | png_ptr->transformations |= PNG_EXPAND; |
| 543 | } |
| 544 | #endif |
| 545 | |
| 546 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| 547 | void |
| 548 | png_set_gray_to_rgb(png_structp png_ptr) |
| 549 | { |
| 550 | png_debug(1, "in png_set_gray_to_rgb\n"); |
| 551 | png_ptr->transformations |= PNG_GRAY_TO_RGB; |
| 552 | } |
| 553 | #endif |
| 554 | |
| 555 | #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
| 556 | /* Convert a RGB image to a grayscale of the same width. This allows us, |
| 557 | * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. |
| 558 | */ |
| 559 | void |
| 560 | png_set_rgb_to_gray(png_structp png_ptr, int error_action, float red, |
| 561 | float green) |
| 562 | { |
| 563 | png_debug(1, "in png_set_rgb_to_gray\n"); |
| 564 | switch(error_action) |
| 565 | { |
| 566 | case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY; |
| 567 | break; |
| 568 | case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; |
| 569 | break; |
| 570 | case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; |
| 571 | } |
| 572 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 573 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
| 574 | png_ptr->transformations |= PNG_EXPAND; |
| 575 | #else |
| 576 | { |
| 577 | png_warning(png_ptr, "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED."); |
| 578 | png_ptr->transformations &= ~PNG_RGB_TO_GRAY; |
| 579 | } |
| 580 | #endif |
| 581 | { |
| 582 | png_byte red_byte = (png_byte)(red*255.0 + 0.5); |
| 583 | png_byte green_byte = (png_byte)(green*255.0 + 0.5); |
| 584 | if(red < 0.0 || green < 0.0) |
| 585 | { |
| 586 | red_byte = 54; |
| 587 | green_byte = 183; |
| 588 | } |
| 589 | else if(red_byte + green_byte > 255) |
| 590 | { |
| 591 | png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); |
| 592 | red_byte = 54; |
| 593 | green_byte = 183; |
| 594 | } |
| 595 | png_ptr->rgb_to_gray_red_coeff = red_byte; |
| 596 | png_ptr->rgb_to_gray_green_coeff = green_byte; |
| 597 | png_ptr->rgb_to_gray_blue_coeff = 255 - red_byte - green_byte; |
| 598 | } |
| 599 | } |
| 600 | #endif |
| 601 | |
| 602 | #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
| 603 | void |
| 604 | png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr |
| 605 | read_user_transform_fn) |
| 606 | { |
| 607 | png_debug(1, "in png_set_read_user_transform_fn\n"); |
| 608 | png_ptr->transformations |= PNG_USER_TRANSFORM; |
| 609 | png_ptr->read_user_transform_fn = read_user_transform_fn; |
| 610 | } |
| 611 | #endif |
| 612 | |
| 613 | /* Initialize everything needed for the read. This includes modifying |
| 614 | * the palette. |
| 615 | */ |
| 616 | void |
| 617 | png_init_read_transformations(png_structp png_ptr) |
| 618 | { |
| 619 | png_debug(1, "in png_init_read_transformations\n"); |
| 620 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 621 | if(png_ptr != NULL) |
| 622 | #endif |
| 623 | { |
| 624 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \ |
| 625 | || defined(PNG_READ_GAMMA_SUPPORTED) |
| 626 | int color_type = png_ptr->color_type; |
| 627 | #endif |
| 628 | |
| 629 | #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 630 | if (png_ptr->transformations & PNG_BACKGROUND_EXPAND) |
| 631 | { |
| 632 | if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */ |
| 633 | { |
| 634 | /* expand background chunk. */ |
| 635 | switch (png_ptr->bit_depth) |
| 636 | { |
| 637 | case 1: |
| 638 | png_ptr->background.gray *= (png_uint_16)0xff; |
| 639 | png_ptr->background.red = png_ptr->background.green = |
| 640 | png_ptr->background.blue = png_ptr->background.gray; |
| 641 | break; |
| 642 | case 2: |
| 643 | png_ptr->background.gray *= (png_uint_16)0x55; |
| 644 | png_ptr->background.red = png_ptr->background.green = |
| 645 | png_ptr->background.blue = png_ptr->background.gray; |
| 646 | break; |
| 647 | case 4: |
| 648 | png_ptr->background.gray *= (png_uint_16)0x11; |
| 649 | png_ptr->background.red = png_ptr->background.green = |
| 650 | png_ptr->background.blue = png_ptr->background.gray; |
| 651 | break; |
| 652 | case 8: |
| 653 | case 16: |
| 654 | png_ptr->background.red = png_ptr->background.green = |
| 655 | png_ptr->background.blue = png_ptr->background.gray; |
| 656 | break; |
| 657 | } |
| 658 | } |
| 659 | else if (color_type == PNG_COLOR_TYPE_PALETTE) |
| 660 | { |
| 661 | png_ptr->background.red = |
| 662 | png_ptr->palette[png_ptr->background.index].red; |
| 663 | png_ptr->background.green = |
| 664 | png_ptr->palette[png_ptr->background.index].green; |
| 665 | png_ptr->background.blue = |
| 666 | png_ptr->palette[png_ptr->background.index].blue; |
| 667 | |
| 668 | #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
| 669 | if (png_ptr->transformations & PNG_INVERT_ALPHA) |
| 670 | { |
| 671 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
| 672 | if (!(png_ptr->transformations & PNG_EXPAND)) |
| 673 | #endif |
| 674 | { |
| 675 | /* invert the alpha channel (in tRNS) unless the pixels are |
| 676 | going to be expanded, in which case leave it for later */ |
| 677 | int i,istop; |
| 678 | istop=(int)png_ptr->num_trans; |
| 679 | for (i=0; i<istop; i++) |
| 680 | png_ptr->trans[i] = 255 - png_ptr->trans[i]; |
| 681 | } |
| 682 | } |
| 683 | #endif |
| 684 | |
| 685 | } |
| 686 | } |
| 687 | #endif |
| 688 | |
| 689 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 690 | png_ptr->background_1 = png_ptr->background; |
| 691 | #endif |
| 692 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 693 | if (png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) |
| 694 | { |
| 695 | png_build_gamma_table(png_ptr); |
| 696 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 697 | if (png_ptr->transformations & PNG_BACKGROUND) |
| 698 | { |
| 699 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
| 700 | { |
| 701 | png_color back, back_1; |
| 702 | png_colorp palette = png_ptr->palette; |
| 703 | int num_palette = png_ptr->num_palette; |
| 704 | int i; |
| 705 | |
| 706 | if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
| 707 | { |
| 708 | back.red = png_ptr->gamma_table[png_ptr->background.red]; |
| 709 | back.green = png_ptr->gamma_table[png_ptr->background.green]; |
| 710 | back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
| 711 | |
| 712 | back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
| 713 | back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
| 714 | back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
| 715 | } |
| 716 | else |
| 717 | { |
| 718 | double g, gs; |
| 719 | |
| 720 | switch (png_ptr->background_gamma_type) |
| 721 | { |
| 722 | case PNG_BACKGROUND_GAMMA_SCREEN: |
| 723 | g = (png_ptr->screen_gamma); |
| 724 | gs = 1.0; |
| 725 | break; |
| 726 | case PNG_BACKGROUND_GAMMA_FILE: |
| 727 | g = 1.0 / (png_ptr->gamma); |
| 728 | gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
| 729 | break; |
| 730 | case PNG_BACKGROUND_GAMMA_UNIQUE: |
| 731 | g = 1.0 / (png_ptr->background_gamma); |
| 732 | gs = 1.0 / (png_ptr->background_gamma * |
| 733 | png_ptr->screen_gamma); |
| 734 | break; |
| 735 | default: |
| 736 | g = 1.0; /* back_1 */ |
| 737 | gs = 1.0; /* back */ |
| 738 | } |
| 739 | |
| 740 | if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD) |
| 741 | { |
| 742 | back.red = (png_byte)png_ptr->background.red; |
| 743 | back.green = (png_byte)png_ptr->background.green; |
| 744 | back.blue = (png_byte)png_ptr->background.blue; |
| 745 | } |
| 746 | else |
| 747 | { |
| 748 | back.red = (png_byte)(pow( |
| 749 | (double)png_ptr->background.red/255, gs) * 255.0 + .5); |
| 750 | back.green = (png_byte)(pow( |
| 751 | (double)png_ptr->background.green/255, gs) * 255.0 + .5); |
| 752 | back.blue = (png_byte)(pow( |
| 753 | (double)png_ptr->background.blue/255, gs) * 255.0 + .5); |
| 754 | } |
| 755 | |
| 756 | back_1.red = (png_byte)(pow( |
| 757 | (double)png_ptr->background.red/255, g) * 255.0 + .5); |
| 758 | back_1.green = (png_byte)(pow( |
| 759 | (double)png_ptr->background.green/255, g) * 255.0 + .5); |
| 760 | back_1.blue = (png_byte)(pow( |
| 761 | (double)png_ptr->background.blue/255, g) * 255.0 + .5); |
| 762 | } |
| 763 | |
| 764 | for (i = 0; i < num_palette; i++) |
| 765 | { |
| 766 | if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
| 767 | { |
| 768 | if (png_ptr->trans[i] == 0) |
| 769 | { |
| 770 | palette[i] = back; |
| 771 | } |
| 772 | else /* if (png_ptr->trans[i] != 0xff) */ |
| 773 | { |
| 774 | png_byte v, w; |
| 775 | |
| 776 | v = png_ptr->gamma_to_1[palette[i].red]; |
| 777 | png_composite(w, v, png_ptr->trans[i], back_1.red); |
| 778 | palette[i].red = png_ptr->gamma_from_1[w]; |
| 779 | |
| 780 | v = png_ptr->gamma_to_1[palette[i].green]; |
| 781 | png_composite(w, v, png_ptr->trans[i], back_1.green); |
| 782 | palette[i].green = png_ptr->gamma_from_1[w]; |
| 783 | |
| 784 | v = png_ptr->gamma_to_1[palette[i].blue]; |
| 785 | png_composite(w, v, png_ptr->trans[i], back_1.blue); |
| 786 | palette[i].blue = png_ptr->gamma_from_1[w]; |
| 787 | } |
| 788 | } |
| 789 | else |
| 790 | { |
| 791 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| 792 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| 793 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| 794 | } |
| 795 | } |
| 796 | } |
| 797 | /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN)*/ |
| 798 | else |
| 799 | /* color_type != PNG_COLOR_TYPE_PALETTE */ |
| 800 | { |
| 801 | double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1); |
| 802 | double g = 1.0; |
| 803 | double gs = 1.0; |
| 804 | |
| 805 | switch (png_ptr->background_gamma_type) |
| 806 | { |
| 807 | case PNG_BACKGROUND_GAMMA_SCREEN: |
| 808 | g = (png_ptr->screen_gamma); |
| 809 | gs = 1.0; |
| 810 | break; |
| 811 | case PNG_BACKGROUND_GAMMA_FILE: |
| 812 | g = 1.0 / (png_ptr->gamma); |
| 813 | gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
| 814 | break; |
| 815 | case PNG_BACKGROUND_GAMMA_UNIQUE: |
| 816 | g = 1.0 / (png_ptr->background_gamma); |
| 817 | gs = 1.0 / (png_ptr->background_gamma * |
| 818 | png_ptr->screen_gamma); |
| 819 | break; |
| 820 | } |
| 821 | |
| 822 | if (color_type & PNG_COLOR_MASK_COLOR) |
| 823 | { |
| 824 | /* RGB or RGBA */ |
| 825 | png_ptr->background_1.red = (png_uint_16)(pow( |
| 826 | (double)png_ptr->background.red / m, g) * m + .5); |
| 827 | png_ptr->background_1.green = (png_uint_16)(pow( |
| 828 | (double)png_ptr->background.green / m, g) * m + .5); |
| 829 | png_ptr->background_1.blue = (png_uint_16)(pow( |
| 830 | (double)png_ptr->background.blue / m, g) * m + .5); |
| 831 | png_ptr->background.red = (png_uint_16)(pow( |
| 832 | (double)png_ptr->background.red / m, gs) * m + .5); |
| 833 | png_ptr->background.green = (png_uint_16)(pow( |
| 834 | (double)png_ptr->background.green / m, gs) * m + .5); |
| 835 | png_ptr->background.blue = (png_uint_16)(pow( |
| 836 | (double)png_ptr->background.blue / m, gs) * m + .5); |
| 837 | } |
| 838 | else |
| 839 | { |
| 840 | /* GRAY or GRAY ALPHA */ |
| 841 | png_ptr->background_1.gray = (png_uint_16)(pow( |
| 842 | (double)png_ptr->background.gray / m, g) * m + .5); |
| 843 | png_ptr->background.gray = (png_uint_16)(pow( |
| 844 | (double)png_ptr->background.gray / m, gs) * m + .5); |
| 845 | } |
| 846 | } |
| 847 | } |
| 848 | else |
| 849 | /* transformation does not include PNG_BACKGROUND */ |
| 850 | #endif |
| 851 | if (color_type == PNG_COLOR_TYPE_PALETTE) |
| 852 | { |
| 853 | png_colorp palette = png_ptr->palette; |
| 854 | int num_palette = png_ptr->num_palette; |
| 855 | int i; |
| 856 | |
| 857 | for (i = 0; i < num_palette; i++) |
| 858 | { |
| 859 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| 860 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| 861 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| 862 | } |
| 863 | } |
| 864 | } |
| 865 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 866 | else |
| 867 | #endif |
| 868 | #endif |
| 869 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 870 | /* No GAMMA transformation */ |
| 871 | if (png_ptr->transformations & PNG_BACKGROUND && |
| 872 | color_type == PNG_COLOR_TYPE_PALETTE) |
| 873 | { |
| 874 | int i; |
| 875 | int istop = (int)png_ptr->num_trans; |
| 876 | png_color back; |
| 877 | png_colorp palette = png_ptr->palette; |
| 878 | |
| 879 | back.red = (png_byte)png_ptr->background.red; |
| 880 | back.green = (png_byte)png_ptr->background.green; |
| 881 | back.blue = (png_byte)png_ptr->background.blue; |
| 882 | |
| 883 | for (i = 0; i < istop; i++) |
| 884 | { |
| 885 | if (png_ptr->trans[i] == 0) |
| 886 | { |
| 887 | palette[i] = back; |
| 888 | } |
| 889 | else if (png_ptr->trans[i] != 0xff) |
| 890 | { |
| 891 | /* The png_composite() macro is defined in png.h */ |
| 892 | png_composite(palette[i].red, palette[i].red, |
| 893 | png_ptr->trans[i], back.red); |
| 894 | png_composite(palette[i].green, palette[i].green, |
| 895 | png_ptr->trans[i], back.green); |
| 896 | png_composite(palette[i].blue, palette[i].blue, |
| 897 | png_ptr->trans[i], back.blue); |
| 898 | } |
| 899 | } |
| 900 | } |
| 901 | #endif |
| 902 | |
| 903 | #if defined(PNG_READ_SHIFT_SUPPORTED) |
| 904 | if ((png_ptr->transformations & PNG_SHIFT) && |
| 905 | color_type == PNG_COLOR_TYPE_PALETTE) |
| 906 | { |
| 907 | png_uint_16 i; |
| 908 | png_uint_16 istop = png_ptr->num_palette; |
| 909 | int sr = 8 - png_ptr->sig_bit.red; |
| 910 | int sg = 8 - png_ptr->sig_bit.green; |
| 911 | int sb = 8 - png_ptr->sig_bit.blue; |
| 912 | |
| 913 | if (sr < 0 || sr > 8) |
| 914 | sr = 0; |
| 915 | if (sg < 0 || sg > 8) |
| 916 | sg = 0; |
| 917 | if (sb < 0 || sb > 8) |
| 918 | sb = 0; |
| 919 | for (i = 0; i < istop; i++) |
| 920 | { |
| 921 | png_ptr->palette[i].red >>= sr; |
| 922 | png_ptr->palette[i].green >>= sg; |
| 923 | png_ptr->palette[i].blue >>= sb; |
| 924 | } |
| 925 | } |
| 926 | #endif |
| 927 | } |
| 928 | } |
| 929 | |
| 930 | /* Modify the info structure to reflect the transformations. The |
| 931 | * info should be updated so a PNG file could be written with it, |
| 932 | * assuming the transformations result in valid PNG data. |
| 933 | */ |
| 934 | void |
| 935 | png_read_transform_info(png_structp png_ptr, png_infop info_ptr) |
| 936 | { |
| 937 | png_debug(1, "in png_read_transform_info\n"); |
| 938 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
| 939 | if (png_ptr->transformations & PNG_EXPAND) |
| 940 | { |
| 941 | if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 942 | { |
| 943 | if (png_ptr->num_trans) |
| 944 | info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
| 945 | else |
| 946 | info_ptr->color_type = PNG_COLOR_TYPE_RGB; |
| 947 | info_ptr->bit_depth = 8; |
| 948 | info_ptr->num_trans = 0; |
| 949 | } |
| 950 | else |
| 951 | { |
| 952 | if (png_ptr->num_trans) |
| 953 | info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
| 954 | if (info_ptr->bit_depth < 8) |
| 955 | info_ptr->bit_depth = 8; |
| 956 | info_ptr->num_trans = 0; |
| 957 | } |
| 958 | } |
| 959 | #endif |
| 960 | |
| 961 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 962 | if (png_ptr->transformations & PNG_BACKGROUND) |
| 963 | { |
| 964 | info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
| 965 | info_ptr->num_trans = 0; |
| 966 | info_ptr->background = png_ptr->background; |
| 967 | } |
| 968 | #endif |
| 969 | |
| 970 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 971 | if (png_ptr->transformations & PNG_GAMMA) |
| 972 | info_ptr->gamma = png_ptr->gamma; |
| 973 | #endif |
| 974 | |
| 975 | #if defined(PNG_READ_16_TO_8_SUPPORTED) |
| 976 | if ((png_ptr->transformations & PNG_16_TO_8) && info_ptr->bit_depth == 16) |
| 977 | info_ptr->bit_depth = 8; |
| 978 | #endif |
| 979 | |
| 980 | #if defined(PNG_READ_DITHER_SUPPORTED) |
| 981 | if (png_ptr->transformations & PNG_DITHER) |
| 982 | { |
| 983 | if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
| 984 | (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && |
| 985 | png_ptr->palette_lookup && info_ptr->bit_depth == 8) |
| 986 | { |
| 987 | info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; |
| 988 | } |
| 989 | } |
| 990 | #endif |
| 991 | |
| 992 | #if defined(PNG_READ_PACK_SUPPORTED) |
| 993 | if ((png_ptr->transformations & PNG_PACK) && info_ptr->bit_depth < 8) |
| 994 | info_ptr->bit_depth = 8; |
| 995 | #endif |
| 996 | |
| 997 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| 998 | if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
| 999 | info_ptr->color_type |= PNG_COLOR_MASK_COLOR; |
| 1000 | #endif |
| 1001 | |
| 1002 | #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
| 1003 | if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
| 1004 | info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; |
| 1005 | #endif |
| 1006 | |
| 1007 | if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 1008 | info_ptr->channels = 1; |
| 1009 | else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) |
| 1010 | info_ptr->channels = 3; |
| 1011 | else |
| 1012 | info_ptr->channels = 1; |
| 1013 | |
| 1014 | #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
| 1015 | if (png_ptr->transformations & PNG_STRIP_ALPHA) |
| 1016 | info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
| 1017 | #endif |
| 1018 | |
| 1019 | if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) |
| 1020 | info_ptr->channels++; |
| 1021 | |
| 1022 | #if defined(PNG_READ_FILLER_SUPPORTED) |
| 1023 | /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ |
| 1024 | if (png_ptr->transformations & PNG_FILLER && |
| 1025 | (info_ptr->color_type == PNG_COLOR_TYPE_RGB || |
| 1026 | info_ptr->color_type == PNG_COLOR_TYPE_GRAY)) |
| 1027 | ++info_ptr->channels; |
| 1028 | #endif |
| 1029 | |
| 1030 | info_ptr->pixel_depth = (png_byte)(info_ptr->channels * |
| 1031 | info_ptr->bit_depth); |
| 1032 | info_ptr->rowbytes = ((info_ptr->width * info_ptr->pixel_depth + 7) >> 3); |
| 1033 | } |
| 1034 | |
| 1035 | /* Transform the row. The order of transformations is significant, |
| 1036 | * and is very touchy. If you add a transformation, take care to |
| 1037 | * decide how it fits in with the other transformations here. |
| 1038 | */ |
| 1039 | void |
| 1040 | png_do_read_transformations(png_structp png_ptr) |
| 1041 | { |
| 1042 | png_debug(1, "in png_do_read_transformations\n"); |
| 1043 | #if !defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1044 | if (png_ptr->row_buf == NULL) |
| 1045 | { |
| 1046 | #if !defined(PNG_NO_STDIO) |
| 1047 | char msg[50]; |
| 1048 | |
| 1049 | sprintf(msg, "NULL row buffer for row %ld, pass %d", png_ptr->row_number, |
| 1050 | png_ptr->pass); |
| 1051 | png_error(png_ptr, msg); |
| 1052 | #else |
| 1053 | png_error(png_ptr, "NULL row buffer"); |
| 1054 | #endif |
| 1055 | } |
| 1056 | #endif |
| 1057 | |
| 1058 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
| 1059 | if (png_ptr->transformations & PNG_EXPAND) |
| 1060 | { |
| 1061 | if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) |
| 1062 | { |
| 1063 | png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1064 | png_ptr->palette, png_ptr->trans, png_ptr->num_trans); |
| 1065 | } |
| 1066 | else |
| 1067 | { |
| 1068 | if (png_ptr->num_trans) |
| 1069 | png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1070 | &(png_ptr->trans_values)); |
| 1071 | else |
| 1072 | png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1073 | NULL); |
| 1074 | } |
| 1075 | } |
| 1076 | #endif |
| 1077 | |
| 1078 | #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
| 1079 | if (png_ptr->transformations & PNG_STRIP_ALPHA) |
| 1080 | png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1081 | PNG_FLAG_FILLER_AFTER); |
| 1082 | #endif |
| 1083 | |
| 1084 | #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
| 1085 | if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
| 1086 | { |
| 1087 | int rgb_error = |
| 1088 | png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1089 | if(rgb_error) |
| 1090 | { |
| 1091 | png_ptr->rgb_to_gray_status=1; |
| 1092 | if(png_ptr->transformations == PNG_RGB_TO_GRAY_WARN) |
| 1093 | png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
| 1094 | if(png_ptr->transformations == PNG_RGB_TO_GRAY_ERR) |
| 1095 | png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
| 1096 | } |
| 1097 | } |
| 1098 | #endif |
| 1099 | |
| 1100 | /* |
| 1101 | From Andreas Dilger e-mail to png-implement, 26 March 1998: |
| 1102 | |
| 1103 | In most cases, the "simple transparency" should be done prior to doing |
| 1104 | gray-to-RGB, or you will have to test 3x as many bytes to check if a |
| 1105 | pixel is transparent. You would also need to make sure that the |
| 1106 | transparency information is upgraded to RGB. |
| 1107 | |
| 1108 | To summarize, the current flow is: |
| 1109 | - Gray + simple transparency -> compare 1 or 2 gray bytes and composite |
| 1110 | with background "in place" if transparent, |
| 1111 | convert to RGB if necessary |
| 1112 | - Gray + alpha -> composite with gray background and remove alpha bytes, |
| 1113 | convert to RGB if necessary |
| 1114 | |
| 1115 | To support RGB backgrounds for gray images we need: |
| 1116 | - Gray + simple transparency -> convert to RGB + simple transparency, compare |
| 1117 | 3 or 6 bytes and composite with background |
| 1118 | "in place" if transparent (3x compare/pixel |
| 1119 | compared to doing composite with gray bkgrnd) |
| 1120 | - Gray + alpha -> convert to RGB + alpha, composite with background and |
| 1121 | remove alpha bytes (3x float operations/pixel |
| 1122 | compared with composite on gray background) |
| 1123 | |
| 1124 | Greg's change will do this. The reason it wasn't done before is for |
| 1125 | performance, as this increases the per-pixel operations. If we would check |
| 1126 | in advance if the background was gray or RGB, and position the gray-to-RGB |
| 1127 | transform appropriately, then it would save a lot of work/time. |
| 1128 | */ |
| 1129 | |
| 1130 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| 1131 | /* if gray -> RGB, do so now only if background is non-gray; else do later |
| 1132 | * for performance reasons */ |
| 1133 | if (png_ptr->transformations & PNG_GRAY_TO_RGB && |
| 1134 | !(png_ptr->flags & PNG_FLAG_BACKGROUND_IS_GRAY)) |
| 1135 | png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1136 | #endif |
| 1137 | |
| 1138 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 1139 | if ((png_ptr->transformations & PNG_BACKGROUND) && |
| 1140 | ((png_ptr->num_trans != 0 ) || |
| 1141 | (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) |
| 1142 | png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1143 | &(png_ptr->trans_values), &(png_ptr->background), |
| 1144 | &(png_ptr->background_1), |
| 1145 | png_ptr->gamma_table, png_ptr->gamma_from_1, |
| 1146 | png_ptr->gamma_to_1, png_ptr->gamma_16_table, |
| 1147 | png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, |
| 1148 | png_ptr->gamma_shift); |
| 1149 | #endif |
| 1150 | |
| 1151 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 1152 | if ((png_ptr->transformations & PNG_GAMMA) && |
| 1153 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 1154 | !((png_ptr->transformations & PNG_BACKGROUND) && |
| 1155 | ((png_ptr->num_trans != 0) || |
| 1156 | (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && |
| 1157 | #endif |
| 1158 | (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) |
| 1159 | png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1160 | png_ptr->gamma_table, png_ptr->gamma_16_table, |
| 1161 | png_ptr->gamma_shift); |
| 1162 | #endif |
| 1163 | |
| 1164 | #if defined(PNG_READ_16_TO_8_SUPPORTED) |
| 1165 | if (png_ptr->transformations & PNG_16_TO_8) |
| 1166 | png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1167 | #endif |
| 1168 | |
| 1169 | #if defined(PNG_READ_DITHER_SUPPORTED) |
| 1170 | if (png_ptr->transformations & PNG_DITHER) |
| 1171 | { |
| 1172 | png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1173 | png_ptr->palette_lookup, png_ptr->dither_index); |
| 1174 | if(png_ptr->row_info.rowbytes == (png_uint_32)0) |
| 1175 | png_error(png_ptr, "png_do_dither returned rowbytes=0"); |
| 1176 | } |
| 1177 | #endif |
| 1178 | |
| 1179 | #if defined(PNG_READ_INVERT_SUPPORTED) |
| 1180 | if (png_ptr->transformations & PNG_INVERT_MONO) |
| 1181 | png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1182 | #endif |
| 1183 | |
| 1184 | #if defined(PNG_READ_SHIFT_SUPPORTED) |
| 1185 | if (png_ptr->transformations & PNG_SHIFT) |
| 1186 | png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1187 | &(png_ptr->shift)); |
| 1188 | #endif |
| 1189 | |
| 1190 | #if defined(PNG_READ_PACK_SUPPORTED) |
| 1191 | if (png_ptr->transformations & PNG_PACK) |
| 1192 | png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1193 | #endif |
| 1194 | |
| 1195 | #if defined(PNG_READ_BGR_SUPPORTED) |
| 1196 | if (png_ptr->transformations & PNG_BGR) |
| 1197 | png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1198 | #endif |
| 1199 | |
| 1200 | #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
| 1201 | if (png_ptr->transformations & PNG_PACKSWAP) |
| 1202 | png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1203 | #endif |
| 1204 | |
| 1205 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| 1206 | /* if gray -> RGB, do so now only if we did not do so above */ |
| 1207 | if (png_ptr->transformations & PNG_GRAY_TO_RGB && |
| 1208 | png_ptr->flags & PNG_FLAG_BACKGROUND_IS_GRAY) |
| 1209 | png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1210 | #endif |
| 1211 | |
| 1212 | #if defined(PNG_READ_FILLER_SUPPORTED) |
| 1213 | if (png_ptr->transformations & PNG_FILLER) |
| 1214 | png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
| 1215 | (png_uint_32)png_ptr->filler, png_ptr->flags); |
| 1216 | #endif |
| 1217 | |
| 1218 | #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
| 1219 | if (png_ptr->transformations & PNG_INVERT_ALPHA) |
| 1220 | png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1221 | #endif |
| 1222 | |
| 1223 | #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) |
| 1224 | if (png_ptr->transformations & PNG_SWAP_ALPHA) |
| 1225 | png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1226 | #endif |
| 1227 | |
| 1228 | #if defined(PNG_READ_SWAP_SUPPORTED) |
| 1229 | if (png_ptr->transformations & PNG_SWAP_BYTES) |
| 1230 | png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
| 1231 | #endif |
| 1232 | |
| 1233 | #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
| 1234 | if (png_ptr->transformations & PNG_USER_TRANSFORM) |
| 1235 | if(png_ptr->read_user_transform_fn != NULL) |
| 1236 | (*(png_ptr->read_user_transform_fn)) /* user read transform function */ |
| 1237 | (png_ptr, /* png_ptr */ |
| 1238 | &(png_ptr->row_info), /* row_info: */ |
| 1239 | /* png_uint_32 width; width of row */ |
| 1240 | /* png_uint_32 rowbytes; number of bytes in row */ |
| 1241 | /* png_byte color_type; color type of pixels */ |
| 1242 | /* png_byte bit_depth; bit depth of samples */ |
| 1243 | /* png_byte channels; number of channels (1-4) */ |
| 1244 | /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
| 1245 | png_ptr->row_buf + 1); /* start of pixel data for row */ |
| 1246 | #endif |
| 1247 | |
| 1248 | } |
| 1249 | |
| 1250 | #if defined(PNG_READ_PACK_SUPPORTED) |
| 1251 | /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, |
| 1252 | * without changing the actual values. Thus, if you had a row with |
| 1253 | * a bit depth of 1, you would end up with bytes that only contained |
| 1254 | * the numbers 0 or 1. If you would rather they contain 0 and 255, use |
| 1255 | * png_do_shift() after this. |
| 1256 | */ |
| 1257 | void |
| 1258 | png_do_unpack(png_row_infop row_info, png_bytep row) |
| 1259 | { |
| 1260 | png_debug(1, "in png_do_unpack\n"); |
| 1261 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1262 | if (row != NULL && row_info != NULL && row_info->bit_depth < 8) |
| 1263 | #else |
| 1264 | if (row_info->bit_depth < 8) |
| 1265 | #endif |
| 1266 | { |
| 1267 | png_uint_32 i; |
| 1268 | png_uint_32 row_width=row_info->width; |
| 1269 | |
| 1270 | switch (row_info->bit_depth) |
| 1271 | { |
| 1272 | case 1: |
| 1273 | { |
| 1274 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); |
| 1275 | png_bytep dp = row + (png_size_t)row_width - 1; |
| 1276 | png_uint_32 shift = 7 - (int)((row_width + 7) & 7); |
| 1277 | for (i = 0; i < row_width; i++) |
| 1278 | { |
| 1279 | *dp = (png_byte)((*sp >> shift) & 0x1); |
| 1280 | if (shift == 7) |
| 1281 | { |
| 1282 | shift = 0; |
| 1283 | sp--; |
| 1284 | } |
| 1285 | else |
| 1286 | shift++; |
| 1287 | |
| 1288 | dp--; |
| 1289 | } |
| 1290 | break; |
| 1291 | } |
| 1292 | case 2: |
| 1293 | { |
| 1294 | |
| 1295 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); |
| 1296 | png_bytep dp = row + (png_size_t)row_width - 1; |
| 1297 | png_uint_32 shift = (int)((3 - ((row_width + 3) & 3)) << 1); |
| 1298 | for (i = 0; i < row_width; i++) |
| 1299 | { |
| 1300 | *dp = (png_byte)((*sp >> shift) & 0x3); |
| 1301 | if (shift == 6) |
| 1302 | { |
| 1303 | shift = 0; |
| 1304 | sp--; |
| 1305 | } |
| 1306 | else |
| 1307 | shift += 2; |
| 1308 | |
| 1309 | dp--; |
| 1310 | } |
| 1311 | break; |
| 1312 | } |
| 1313 | case 4: |
| 1314 | { |
| 1315 | png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); |
| 1316 | png_bytep dp = row + (png_size_t)row_width - 1; |
| 1317 | png_uint_32 shift = (int)((1 - ((row_width + 1) & 1)) << 2); |
| 1318 | for (i = 0; i < row_width; i++) |
| 1319 | { |
| 1320 | *dp = (png_byte)((*sp >> shift) & 0xf); |
| 1321 | if (shift == 4) |
| 1322 | { |
| 1323 | shift = 0; |
| 1324 | sp--; |
| 1325 | } |
| 1326 | else |
| 1327 | shift = 4; |
| 1328 | |
| 1329 | dp--; |
| 1330 | } |
| 1331 | break; |
| 1332 | } |
| 1333 | } |
| 1334 | row_info->bit_depth = 8; |
| 1335 | row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
| 1336 | row_info->rowbytes = row_width * row_info->channels; |
| 1337 | } |
| 1338 | } |
| 1339 | #endif |
| 1340 | |
| 1341 | #if defined(PNG_READ_SHIFT_SUPPORTED) |
| 1342 | /* Reverse the effects of png_do_shift. This routine merely shifts the |
| 1343 | * pixels back to their significant bits values. Thus, if you have |
| 1344 | * a row of bit depth 8, but only 5 are significant, this will shift |
| 1345 | * the values back to 0 through 31. |
| 1346 | */ |
| 1347 | void |
| 1348 | png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits) |
| 1349 | { |
| 1350 | png_debug(1, "in png_do_unshift\n"); |
| 1351 | if ( |
| 1352 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1353 | row != NULL && row_info != NULL && sig_bits != NULL && |
| 1354 | #endif |
| 1355 | row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
| 1356 | { |
| 1357 | int shift[4]; |
| 1358 | int channels = 0; |
| 1359 | int c; |
| 1360 | png_uint_16 value = 0; |
| 1361 | png_uint_32 row_width = row_info->width; |
| 1362 | |
| 1363 | if (row_info->color_type & PNG_COLOR_MASK_COLOR) |
| 1364 | { |
| 1365 | shift[channels++] = row_info->bit_depth - sig_bits->red; |
| 1366 | shift[channels++] = row_info->bit_depth - sig_bits->green; |
| 1367 | shift[channels++] = row_info->bit_depth - sig_bits->blue; |
| 1368 | } |
| 1369 | else |
| 1370 | { |
| 1371 | shift[channels++] = row_info->bit_depth - sig_bits->gray; |
| 1372 | } |
| 1373 | if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
| 1374 | { |
| 1375 | shift[channels++] = row_info->bit_depth - sig_bits->alpha; |
| 1376 | } |
| 1377 | |
| 1378 | for (c = 0; c < channels; c++) |
| 1379 | { |
| 1380 | if (shift[c] <= 0) |
| 1381 | shift[c] = 0; |
| 1382 | else |
| 1383 | value = 1; |
| 1384 | } |
| 1385 | |
| 1386 | if (!value) |
| 1387 | return; |
| 1388 | |
| 1389 | switch (row_info->bit_depth) |
| 1390 | { |
| 1391 | case 2: |
| 1392 | { |
| 1393 | png_bytep bp; |
| 1394 | png_uint_32 i; |
| 1395 | png_uint_32 istop = row_info->rowbytes; |
| 1396 | |
| 1397 | for (bp = row, i = 0; i < istop; i++) |
| 1398 | { |
| 1399 | *bp >>= 1; |
| 1400 | *bp++ &= 0x55; |
| 1401 | } |
| 1402 | break; |
| 1403 | } |
| 1404 | case 4: |
| 1405 | { |
| 1406 | png_bytep bp = row; |
| 1407 | png_uint_32 i; |
| 1408 | png_uint_32 istop = row_info->rowbytes; |
| 1409 | png_byte mask = (png_byte)(((int)0xf0 >> shift[0]) & (int)0xf0) | |
| 1410 | (png_byte)((int)0xf >> shift[0]); |
| 1411 | |
| 1412 | for (i = 0; i < istop; i++) |
| 1413 | { |
| 1414 | *bp >>= shift[0]; |
| 1415 | *bp++ &= mask; |
| 1416 | } |
| 1417 | break; |
| 1418 | } |
| 1419 | case 8: |
| 1420 | { |
| 1421 | png_bytep bp = row; |
| 1422 | png_uint_32 i; |
| 1423 | png_uint_32 istop = row_width * channels; |
| 1424 | |
| 1425 | for (i = 0; i < istop; i++) |
| 1426 | { |
| 1427 | *bp++ >>= shift[i%channels]; |
| 1428 | } |
| 1429 | break; |
| 1430 | } |
| 1431 | case 16: |
| 1432 | { |
| 1433 | png_bytep bp = row; |
| 1434 | png_uint_32 i; |
| 1435 | png_uint_32 istop = channels * row_width; |
| 1436 | |
| 1437 | for (i = 0; i < istop; i++) |
| 1438 | { |
| 1439 | value = (png_uint_16)((*bp << 8) + *(bp + 1)); |
| 1440 | value >>= shift[i%channels]; |
| 1441 | *bp++ = (png_byte)(value >> 8); |
| 1442 | *bp++ = (png_byte)(value & 0xff); |
| 1443 | } |
| 1444 | break; |
| 1445 | } |
| 1446 | } |
| 1447 | } |
| 1448 | } |
| 1449 | #endif |
| 1450 | |
| 1451 | #if defined(PNG_READ_16_TO_8_SUPPORTED) |
| 1452 | /* chop rows of bit depth 16 down to 8 */ |
| 1453 | void |
| 1454 | png_do_chop(png_row_infop row_info, png_bytep row) |
| 1455 | { |
| 1456 | png_debug(1, "in png_do_chop\n"); |
| 1457 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1458 | if (row != NULL && row_info != NULL && row_info->bit_depth == 16) |
| 1459 | #else |
| 1460 | if (row_info->bit_depth == 16) |
| 1461 | #endif |
| 1462 | { |
| 1463 | png_bytep sp = row; |
| 1464 | png_bytep dp = row; |
| 1465 | png_uint_32 i; |
| 1466 | png_uint_32 istop = row_info->width * row_info->channels; |
| 1467 | |
| 1468 | for (i = 0; i<istop; i++, sp += 2, dp++) |
| 1469 | { |
| 1470 | #if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED) |
| 1471 | /* This does a more accurate scaling of the 16-bit color |
| 1472 | * value, rather than a simple low-byte truncation. |
| 1473 | * |
| 1474 | * What the ideal calculation should be: |
| 1475 | * *dp = (((((png_uint_32)(*sp) << 8) | |
| 1476 | * (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L; |
| 1477 | * |
| 1478 | * GRR: no, I think this is what it really should be: |
| 1479 | * *dp = (((((png_uint_32)(*sp) << 8) | |
| 1480 | * (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L; |
| 1481 | * |
| 1482 | * GRR: here's the exact calculation with shifts: |
| 1483 | * temp = (((png_uint_32)(*sp) << 8) | (png_uint_32)(*(sp + 1))) + 128L; |
| 1484 | * *dp = (temp - (temp >> 8)) >> 8; |
| 1485 | * |
| 1486 | * Approximate calculation with shift/add instead of multiply/divide: |
| 1487 | * *dp = ((((png_uint_32)(*sp) << 8) | |
| 1488 | * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8; |
| 1489 | * |
| 1490 | * What we actually do to avoid extra shifting and conversion: |
| 1491 | */ |
| 1492 | |
| 1493 | *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0); |
| 1494 | #else |
| 1495 | /* Simply discard the low order byte */ |
| 1496 | *dp = *sp; |
| 1497 | #endif |
| 1498 | } |
| 1499 | row_info->bit_depth = 8; |
| 1500 | row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
| 1501 | row_info->rowbytes = row_info->width * row_info->channels; |
| 1502 | } |
| 1503 | } |
| 1504 | #endif |
| 1505 | |
| 1506 | #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) |
| 1507 | void |
| 1508 | png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) |
| 1509 | { |
| 1510 | png_debug(1, "in png_do_read_swap_alpha\n"); |
| 1511 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1512 | if (row != NULL && row_info != NULL) |
| 1513 | #endif |
| 1514 | { |
| 1515 | png_uint_32 row_width = row_info->width; |
| 1516 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| 1517 | { |
| 1518 | /* This converts from RGBA to ARGB */ |
| 1519 | if (row_info->bit_depth == 8) |
| 1520 | { |
| 1521 | png_bytep sp = row + row_info->rowbytes; |
| 1522 | png_bytep dp = sp; |
| 1523 | png_byte save; |
| 1524 | png_uint_32 i; |
| 1525 | |
| 1526 | for (i = 0; i < row_width; i++) |
| 1527 | { |
| 1528 | save = *(--sp); |
| 1529 | *(--dp) = *(--sp); |
| 1530 | *(--dp) = *(--sp); |
| 1531 | *(--dp) = *(--sp); |
| 1532 | *(--dp) = save; |
| 1533 | } |
| 1534 | } |
| 1535 | /* This converts from RRGGBBAA to AARRGGBB */ |
| 1536 | else |
| 1537 | { |
| 1538 | png_bytep sp = row + row_info->rowbytes; |
| 1539 | png_bytep dp = sp; |
| 1540 | png_byte save[2]; |
| 1541 | png_uint_32 i; |
| 1542 | |
| 1543 | for (i = 0; i < row_width; i++) |
| 1544 | { |
| 1545 | save[0] = *(--sp); |
| 1546 | save[1] = *(--sp); |
| 1547 | *(--dp) = *(--sp); |
| 1548 | *(--dp) = *(--sp); |
| 1549 | *(--dp) = *(--sp); |
| 1550 | *(--dp) = *(--sp); |
| 1551 | *(--dp) = *(--sp); |
| 1552 | *(--dp) = *(--sp); |
| 1553 | *(--dp) = save[0]; |
| 1554 | *(--dp) = save[1]; |
| 1555 | } |
| 1556 | } |
| 1557 | } |
| 1558 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| 1559 | { |
| 1560 | /* This converts from GA to AG */ |
| 1561 | if (row_info->bit_depth == 8) |
| 1562 | { |
| 1563 | png_bytep sp = row + row_info->rowbytes; |
| 1564 | png_bytep dp = sp; |
| 1565 | png_byte save; |
| 1566 | png_uint_32 i; |
| 1567 | |
| 1568 | for (i = 0; i < row_width; i++) |
| 1569 | { |
| 1570 | save = *(--sp); |
| 1571 | *(--dp) = *(--sp); |
| 1572 | *(--dp) = save; |
| 1573 | } |
| 1574 | } |
| 1575 | /* This converts from GGAA to AAGG */ |
| 1576 | else |
| 1577 | { |
| 1578 | png_bytep sp = row + row_info->rowbytes; |
| 1579 | png_bytep dp = sp; |
| 1580 | png_byte save[2]; |
| 1581 | png_uint_32 i; |
| 1582 | |
| 1583 | for (i = 0; i < row_width; i++) |
| 1584 | { |
| 1585 | save[0] = *(--sp); |
| 1586 | save[1] = *(--sp); |
| 1587 | *(--dp) = *(--sp); |
| 1588 | *(--dp) = *(--sp); |
| 1589 | *(--dp) = save[0]; |
| 1590 | *(--dp) = save[1]; |
| 1591 | } |
| 1592 | } |
| 1593 | } |
| 1594 | } |
| 1595 | } |
| 1596 | #endif |
| 1597 | |
| 1598 | #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
| 1599 | void |
| 1600 | png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) |
| 1601 | { |
| 1602 | png_debug(1, "in png_do_read_invert_alpha\n"); |
| 1603 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1604 | if (row != NULL && row_info != NULL) |
| 1605 | #endif |
| 1606 | { |
| 1607 | png_uint_32 row_width = row_info->width; |
| 1608 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| 1609 | { |
| 1610 | /* This inverts the alpha channel in RGBA */ |
| 1611 | if (row_info->bit_depth == 8) |
| 1612 | { |
| 1613 | png_bytep sp = row + row_info->rowbytes; |
| 1614 | png_bytep dp = sp; |
| 1615 | png_uint_32 i; |
| 1616 | |
| 1617 | for (i = 0; i < row_width; i++) |
| 1618 | { |
| 1619 | *(--dp) = 255 - *(--sp); |
| 1620 | *(--dp) = *(--sp); |
| 1621 | *(--dp) = *(--sp); |
| 1622 | *(--dp) = *(--sp); |
| 1623 | } |
| 1624 | } |
| 1625 | /* This inverts the alpha channel in RRGGBBAA */ |
| 1626 | else |
| 1627 | { |
| 1628 | png_bytep sp = row + row_info->rowbytes; |
| 1629 | png_bytep dp = sp; |
| 1630 | png_uint_32 i; |
| 1631 | |
| 1632 | for (i = 0; i < row_width; i++) |
| 1633 | { |
| 1634 | *(--dp) = 255 - *(--sp); |
| 1635 | *(--dp) = 255 - *(--sp); |
| 1636 | *(--dp) = *(--sp); |
| 1637 | *(--dp) = *(--sp); |
| 1638 | *(--dp) = *(--sp); |
| 1639 | *(--dp) = *(--sp); |
| 1640 | *(--dp) = *(--sp); |
| 1641 | *(--dp) = *(--sp); |
| 1642 | } |
| 1643 | } |
| 1644 | } |
| 1645 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| 1646 | { |
| 1647 | /* This inverts the alpha channel in GA */ |
| 1648 | if (row_info->bit_depth == 8) |
| 1649 | { |
| 1650 | png_bytep sp = row + row_info->rowbytes; |
| 1651 | png_bytep dp = sp; |
| 1652 | png_uint_32 i; |
| 1653 | |
| 1654 | for (i = 0; i < row_width; i++) |
| 1655 | { |
| 1656 | *(--dp) = 255 - *(--sp); |
| 1657 | *(--dp) = *(--sp); |
| 1658 | } |
| 1659 | } |
| 1660 | /* This inverts the alpha channel in GGAA */ |
| 1661 | else |
| 1662 | { |
| 1663 | png_bytep sp = row + row_info->rowbytes; |
| 1664 | png_bytep dp = sp; |
| 1665 | png_uint_32 i; |
| 1666 | |
| 1667 | for (i = 0; i < row_width; i++) |
| 1668 | { |
| 1669 | *(--dp) = 255 - *(--sp); |
| 1670 | *(--dp) = 255 - *(--sp); |
| 1671 | *(--dp) = *(--sp); |
| 1672 | *(--dp) = *(--sp); |
| 1673 | } |
| 1674 | } |
| 1675 | } |
| 1676 | } |
| 1677 | } |
| 1678 | #endif |
| 1679 | |
| 1680 | #if defined(PNG_READ_FILLER_SUPPORTED) |
| 1681 | /* Add filler channel if we have RGB color */ |
| 1682 | void |
| 1683 | png_do_read_filler(png_row_infop row_info, png_bytep row, |
| 1684 | png_uint_32 filler, png_uint_32 flags) |
| 1685 | { |
| 1686 | png_uint_32 i; |
| 1687 | png_uint_32 row_width = row_info->width; |
| 1688 | |
| 1689 | png_byte hi_filler = (png_byte)((filler>>8) & 0xff); |
| 1690 | png_byte lo_filler = (png_byte)(filler & 0xff); |
| 1691 | |
| 1692 | png_debug(1, "in png_do_read_filler\n"); |
| 1693 | if ( |
| 1694 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1695 | row != NULL && row_info != NULL && |
| 1696 | #endif |
| 1697 | row_info->color_type == PNG_COLOR_TYPE_GRAY) |
| 1698 | { |
| 1699 | if(row_info->bit_depth == 8) |
| 1700 | { |
| 1701 | /* This changes the data from G to GX */ |
| 1702 | if (flags & PNG_FLAG_FILLER_AFTER) |
| 1703 | { |
| 1704 | png_bytep sp = row + (png_size_t)row_width; |
| 1705 | png_bytep dp = sp + (png_size_t)row_width; |
| 1706 | for (i = 1; i < row_width; i++) |
| 1707 | { |
| 1708 | *(--dp) = lo_filler; |
| 1709 | *(--dp) = *(--sp); |
| 1710 | } |
| 1711 | *(--dp) = lo_filler; |
| 1712 | row_info->channels = 2; |
| 1713 | row_info->pixel_depth = 16; |
| 1714 | row_info->rowbytes = row_width * 2; |
| 1715 | } |
| 1716 | /* This changes the data from G to XG */ |
| 1717 | else |
| 1718 | { |
| 1719 | png_bytep sp = row + (png_size_t)row_width; |
| 1720 | png_bytep dp = sp + (png_size_t)row_width; |
| 1721 | for (i = 0; i < row_width; i++) |
| 1722 | { |
| 1723 | *(--dp) = *(--sp); |
| 1724 | *(--dp) = lo_filler; |
| 1725 | } |
| 1726 | row_info->channels = 2; |
| 1727 | row_info->pixel_depth = 16; |
| 1728 | row_info->rowbytes = row_width * 2; |
| 1729 | } |
| 1730 | } |
| 1731 | else if(row_info->bit_depth == 16) |
| 1732 | { |
| 1733 | /* This changes the data from GG to GGXX */ |
| 1734 | if (flags & PNG_FLAG_FILLER_AFTER) |
| 1735 | { |
| 1736 | png_bytep sp = row + (png_size_t)row_width; |
| 1737 | png_bytep dp = sp + (png_size_t)row_width; |
| 1738 | for (i = 1; i < row_width; i++) |
| 1739 | { |
| 1740 | *(--dp) = hi_filler; |
| 1741 | *(--dp) = lo_filler; |
| 1742 | *(--dp) = *(--sp); |
| 1743 | *(--dp) = *(--sp); |
| 1744 | } |
| 1745 | *(--dp) = hi_filler; |
| 1746 | *(--dp) = lo_filler; |
| 1747 | row_info->channels = 2; |
| 1748 | row_info->pixel_depth = 32; |
| 1749 | row_info->rowbytes = row_width * 2; |
| 1750 | } |
| 1751 | /* This changes the data from GG to XXGG */ |
| 1752 | else |
| 1753 | { |
| 1754 | png_bytep sp = row + (png_size_t)row_width; |
| 1755 | png_bytep dp = sp + (png_size_t)row_width; |
| 1756 | for (i = 0; i < row_width; i++) |
| 1757 | { |
| 1758 | *(--dp) = *(--sp); |
| 1759 | *(--dp) = *(--sp); |
| 1760 | *(--dp) = hi_filler; |
| 1761 | *(--dp) = lo_filler; |
| 1762 | } |
| 1763 | row_info->channels = 2; |
| 1764 | row_info->pixel_depth = 16; |
| 1765 | row_info->rowbytes = row_width * 2; |
| 1766 | } |
| 1767 | } |
| 1768 | } /* COLOR_TYPE == GRAY */ |
| 1769 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
| 1770 | { |
| 1771 | if(row_info->bit_depth == 8) |
| 1772 | { |
| 1773 | /* This changes the data from RGB to RGBX */ |
| 1774 | if (flags & PNG_FLAG_FILLER_AFTER) |
| 1775 | { |
| 1776 | png_bytep sp = row + (png_size_t)row_width * 3; |
| 1777 | png_bytep dp = sp + (png_size_t)row_width; |
| 1778 | for (i = 1; i < row_width; i++) |
| 1779 | { |
| 1780 | *(--dp) = lo_filler; |
| 1781 | *(--dp) = *(--sp); |
| 1782 | *(--dp) = *(--sp); |
| 1783 | *(--dp) = *(--sp); |
| 1784 | } |
| 1785 | *(--dp) = lo_filler; |
| 1786 | row_info->channels = 4; |
| 1787 | row_info->pixel_depth = 32; |
| 1788 | row_info->rowbytes = row_width * 4; |
| 1789 | } |
| 1790 | /* This changes the data from RGB to XRGB */ |
| 1791 | else |
| 1792 | { |
| 1793 | png_bytep sp = row + (png_size_t)row_width * 3; |
| 1794 | png_bytep dp = sp + (png_size_t)row_width; |
| 1795 | for (i = 0; i < row_width; i++) |
| 1796 | { |
| 1797 | *(--dp) = *(--sp); |
| 1798 | *(--dp) = *(--sp); |
| 1799 | *(--dp) = *(--sp); |
| 1800 | *(--dp) = lo_filler; |
| 1801 | } |
| 1802 | row_info->channels = 4; |
| 1803 | row_info->pixel_depth = 32; |
| 1804 | row_info->rowbytes = row_width * 4; |
| 1805 | } |
| 1806 | } |
| 1807 | else if(row_info->bit_depth == 16) |
| 1808 | { |
| 1809 | /* This changes the data from RRGGBB to RRGGBBXX */ |
| 1810 | if (flags & PNG_FLAG_FILLER_AFTER) |
| 1811 | { |
| 1812 | png_bytep sp = row + (png_size_t)row_width * 3; |
| 1813 | png_bytep dp = sp + (png_size_t)row_width; |
| 1814 | for (i = 1; i < row_width; i++) |
| 1815 | { |
| 1816 | *(--dp) = hi_filler; |
| 1817 | *(--dp) = lo_filler; |
| 1818 | *(--dp) = *(--sp); |
| 1819 | *(--dp) = *(--sp); |
| 1820 | *(--dp) = *(--sp); |
| 1821 | *(--dp) = *(--sp); |
| 1822 | *(--dp) = *(--sp); |
| 1823 | *(--dp) = *(--sp); |
| 1824 | } |
| 1825 | *(--dp) = hi_filler; |
| 1826 | *(--dp) = lo_filler; |
| 1827 | row_info->channels = 4; |
| 1828 | row_info->pixel_depth = 64; |
| 1829 | row_info->rowbytes = row_width * 4; |
| 1830 | } |
| 1831 | /* This changes the data from RRGGBB to XXRRGGBB */ |
| 1832 | else |
| 1833 | { |
| 1834 | png_bytep sp = row + (png_size_t)row_width * 3; |
| 1835 | png_bytep dp = sp + (png_size_t)row_width; |
| 1836 | for (i = 0; i < row_width; i++) |
| 1837 | { |
| 1838 | *(--dp) = *(--sp); |
| 1839 | *(--dp) = *(--sp); |
| 1840 | *(--dp) = *(--sp); |
| 1841 | *(--dp) = *(--sp); |
| 1842 | *(--dp) = *(--sp); |
| 1843 | *(--dp) = *(--sp); |
| 1844 | *(--dp) = hi_filler; |
| 1845 | *(--dp) = lo_filler; |
| 1846 | } |
| 1847 | row_info->channels = 4; |
| 1848 | row_info->pixel_depth = 64; |
| 1849 | row_info->rowbytes = row_width * 4; |
| 1850 | } |
| 1851 | } |
| 1852 | } /* COLOR_TYPE == RGB */ |
| 1853 | } |
| 1854 | #endif |
| 1855 | |
| 1856 | #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
| 1857 | /* expand grayscale files to RGB, with or without alpha */ |
| 1858 | void |
| 1859 | png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) |
| 1860 | { |
| 1861 | png_uint_32 i; |
| 1862 | png_uint_32 row_width = row_info->width; |
| 1863 | |
| 1864 | png_debug(1, "in png_do_gray_to_rgb\n"); |
| 1865 | if (row_info->bit_depth >= 8 && |
| 1866 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1867 | row != NULL && row_info != NULL && |
| 1868 | #endif |
| 1869 | !(row_info->color_type & PNG_COLOR_MASK_COLOR)) |
| 1870 | { |
| 1871 | if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
| 1872 | { |
| 1873 | if (row_info->bit_depth == 8) |
| 1874 | { |
| 1875 | png_bytep sp = row + (png_size_t)row_width - 1; |
| 1876 | png_bytep dp = sp + (png_size_t)row_width * 2; |
| 1877 | for (i = 0; i < row_width; i++) |
| 1878 | { |
| 1879 | *(dp--) = *sp; |
| 1880 | *(dp--) = *sp; |
| 1881 | *(dp--) = *sp; |
| 1882 | sp--; |
| 1883 | } |
| 1884 | } |
| 1885 | else |
| 1886 | { |
| 1887 | png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
| 1888 | png_bytep dp = sp + (png_size_t)row_width * 4; |
| 1889 | for (i = 0; i < row_width; i++) |
| 1890 | { |
| 1891 | *(dp--) = *sp; |
| 1892 | *(dp--) = *(sp - 1); |
| 1893 | *(dp--) = *sp; |
| 1894 | *(dp--) = *(sp - 1); |
| 1895 | *(dp--) = *sp; |
| 1896 | *(dp--) = *(sp - 1); |
| 1897 | sp--; |
| 1898 | sp--; |
| 1899 | } |
| 1900 | } |
| 1901 | } |
| 1902 | else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
| 1903 | { |
| 1904 | if (row_info->bit_depth == 8) |
| 1905 | { |
| 1906 | png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
| 1907 | png_bytep dp = sp + (png_size_t)row_width * 2; |
| 1908 | for (i = 0; i < row_width; i++) |
| 1909 | { |
| 1910 | *(dp--) = *(sp--); |
| 1911 | *(dp--) = *sp; |
| 1912 | *(dp--) = *sp; |
| 1913 | *(dp--) = *sp; |
| 1914 | sp--; |
| 1915 | } |
| 1916 | } |
| 1917 | else |
| 1918 | { |
| 1919 | png_bytep sp = row + (png_size_t)row_width * 4 - 1; |
| 1920 | png_bytep dp = sp + (png_size_t)row_width * 4; |
| 1921 | for (i = 0; i < row_width; i++) |
| 1922 | { |
| 1923 | *(dp--) = *(sp--); |
| 1924 | *(dp--) = *(sp--); |
| 1925 | *(dp--) = *sp; |
| 1926 | *(dp--) = *(sp - 1); |
| 1927 | *(dp--) = *sp; |
| 1928 | *(dp--) = *(sp - 1); |
| 1929 | *(dp--) = *sp; |
| 1930 | *(dp--) = *(sp - 1); |
| 1931 | sp--; |
| 1932 | sp--; |
| 1933 | } |
| 1934 | } |
| 1935 | } |
| 1936 | row_info->channels += (png_byte)2; |
| 1937 | row_info->color_type |= PNG_COLOR_MASK_COLOR; |
| 1938 | row_info->pixel_depth = (png_byte)(row_info->channels * |
| 1939 | row_info->bit_depth); |
| 1940 | row_info->rowbytes = ((row_width * |
| 1941 | row_info->pixel_depth + 7) >> 3); |
| 1942 | } |
| 1943 | } |
| 1944 | #endif |
| 1945 | |
| 1946 | #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
| 1947 | /* reduce RGB files to grayscale, with or without alpha |
| 1948 | * using the equation given in Poynton's ColorFAQ at |
| 1949 | * <http://www.inforamp.net/~poynton/> |
| 1950 | * Copyright (c) 1998-01-04 Charles Poynton poynton@inforamp.net |
| 1951 | * |
| 1952 | * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B |
| 1953 | * |
| 1954 | * We approximate this with |
| 1955 | * |
| 1956 | * Y = 0.211 * R + 0.715 * G + 0.074 * B |
| 1957 | * |
| 1958 | * which can be expressed with integers as |
| 1959 | * |
| 1960 | * Y = (54 * R + 183 * G + 19 * B)/256 |
| 1961 | * |
| 1962 | * The calculation is to be done in a linear colorspace. |
| 1963 | * |
| 1964 | * Other integer coefficents can be used via png_set_rgb_to_gray(). |
| 1965 | */ |
| 1966 | int |
| 1967 | png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) |
| 1968 | |
| 1969 | { |
| 1970 | png_uint_32 i; |
| 1971 | |
| 1972 | png_uint_32 row_width = row_info->width; |
| 1973 | int rgb_error = 0; |
| 1974 | |
| 1975 | png_debug(1, "in png_do_rgb_to_gray\n"); |
| 1976 | if ( |
| 1977 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 1978 | row != NULL && row_info != NULL && |
| 1979 | #endif |
| 1980 | (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
| 1981 | { |
| 1982 | png_byte rc = png_ptr->rgb_to_gray_red_coeff; |
| 1983 | png_byte gc = png_ptr->rgb_to_gray_green_coeff; |
| 1984 | png_byte bc = png_ptr->rgb_to_gray_blue_coeff; |
| 1985 | |
| 1986 | if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
| 1987 | { |
| 1988 | if (row_info->bit_depth == 8) |
| 1989 | { |
| 1990 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 1991 | if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
| 1992 | { |
| 1993 | png_bytep sp = row; |
| 1994 | png_bytep dp = row; |
| 1995 | |
| 1996 | for (i = 0; i < row_width; i++) |
| 1997 | { |
| 1998 | png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
| 1999 | png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
| 2000 | png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
| 2001 | if(red != green || red != blue) |
| 2002 | { |
| 2003 | rgb_error |= 1; |
| 2004 | *(dp++) = png_ptr->gamma_from_1[ |
| 2005 | (rc*red+gc*green+bc*blue)>>8]; |
| 2006 | } |
| 2007 | else |
| 2008 | *(dp++) = *(sp-1); |
| 2009 | } |
| 2010 | } |
| 2011 | else |
| 2012 | #endif |
| 2013 | { |
| 2014 | png_bytep sp = row; |
| 2015 | png_bytep dp = row; |
| 2016 | for (i = 0; i < row_width; i++) |
| 2017 | { |
| 2018 | png_byte red = *(sp++); |
| 2019 | png_byte green = *(sp++); |
| 2020 | png_byte blue = *(sp++); |
| 2021 | if(red != green || red != blue) |
| 2022 | { |
| 2023 | rgb_error |= 1; |
| 2024 | *(dp++) = (rc*red+gc*green+bc*blue)>>8; |
| 2025 | } |
| 2026 | else |
| 2027 | *(dp++) = *(sp-1); |
| 2028 | } |
| 2029 | } |
| 2030 | } |
| 2031 | |
| 2032 | else /* RGB bit_depth == 16 */ |
| 2033 | { |
| 2034 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 2035 | if (png_ptr->gamma_16_to_1 != NULL && |
| 2036 | png_ptr->gamma_16_from_1 != NULL) |
| 2037 | { |
| 2038 | png_bytep sp = row; |
| 2039 | png_bytep dp = row; |
| 2040 | for (i = 0; i < row_width; i++) |
| 2041 | { |
| 2042 | png_uint_16 red, green, blue, w; |
| 2043 | |
| 2044 | red = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2045 | green = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2046 | blue = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2047 | |
| 2048 | if(red == green && red == blue) |
| 2049 | w = red; |
| 2050 | else |
| 2051 | { |
| 2052 | png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
| 2053 | png_ptr->gamma_shift][red>>8]; |
| 2054 | png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >> |
| 2055 | png_ptr->gamma_shift][green>>8]; |
| 2056 | png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
| 2057 | png_ptr->gamma_shift][blue>>8]; |
| 2058 | png_uint_16 gray16 = (rc * red_1 + gc * green_1 |
| 2059 | + bc * blue_1)>>8; |
| 2060 | w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
| 2061 | png_ptr->gamma_shift][gray16 >> 8]; |
| 2062 | rgb_error |= 1; |
| 2063 | } |
| 2064 | |
| 2065 | *(dp++) = (w>>8) & 0xff; |
| 2066 | *(dp++) = w & 0xff; |
| 2067 | } |
| 2068 | } |
| 2069 | else |
| 2070 | #endif |
| 2071 | { |
| 2072 | png_bytep sp = row; |
| 2073 | png_bytep dp = row; |
| 2074 | for (i = 0; i < row_width; i++) |
| 2075 | { |
| 2076 | png_uint_16 red, green, blue, gray16; |
| 2077 | |
| 2078 | red = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2079 | green = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2080 | blue = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2081 | |
| 2082 | if(red != green || red != blue) |
| 2083 | rgb_error |= 1; |
| 2084 | gray16 = (rc * red + gc * green + bc * blue)>>8; |
| 2085 | *(dp++) = (gray16>>8) & 0xff; |
| 2086 | *(dp++) = gray16 & 0xff; |
| 2087 | } |
| 2088 | } |
| 2089 | } |
| 2090 | } |
| 2091 | if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
| 2092 | { |
| 2093 | if (row_info->bit_depth == 8) |
| 2094 | { |
| 2095 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 2096 | if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
| 2097 | { |
| 2098 | png_bytep sp = row; |
| 2099 | png_bytep dp = row; |
| 2100 | for (i = 0; i < row_width; i++) |
| 2101 | { |
| 2102 | png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
| 2103 | png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
| 2104 | png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
| 2105 | if(red != green || red != blue) |
| 2106 | rgb_error |= 1; |
| 2107 | *(dp++) = png_ptr->gamma_from_1 |
| 2108 | [(rc*red + gc*green + bc*blue)>>8]; |
| 2109 | *(dp++) = *(sp++); /* alpha */ |
| 2110 | } |
| 2111 | } |
| 2112 | else |
| 2113 | #endif |
| 2114 | { |
| 2115 | png_bytep sp = row; |
| 2116 | png_bytep dp = row; |
| 2117 | for (i = 0; i < row_width; i++) |
| 2118 | { |
| 2119 | png_byte red = *(sp++); |
| 2120 | png_byte green = *(sp++); |
| 2121 | png_byte blue = *(sp++); |
| 2122 | if(red != green || red != blue) |
| 2123 | rgb_error |= 1; |
| 2124 | *(dp++) = (gc*red + gc*green + bc*blue)>>8; |
| 2125 | *(dp++) = *(sp++); /* alpha */ |
| 2126 | } |
| 2127 | } |
| 2128 | } |
| 2129 | else /* RGBA bit_depth == 16 */ |
| 2130 | { |
| 2131 | #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 2132 | if (png_ptr->gamma_16_to_1 != NULL && |
| 2133 | png_ptr->gamma_16_from_1 != NULL) |
| 2134 | { |
| 2135 | png_bytep sp = row; |
| 2136 | png_bytep dp = row; |
| 2137 | for (i = 0; i < row_width; i++) |
| 2138 | { |
| 2139 | png_uint_16 red, green, blue, w; |
| 2140 | |
| 2141 | red = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2142 | green = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2143 | blue = ((*(sp))<<8) | *(sp+1); sp+=2; |
| 2144 | |
| 2145 | if(red == green && red == blue) |
| 2146 | w = red; |
| 2147 | else |
| 2148 | { |
| 2149 | png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
| 2150 | png_ptr->gamma_shift][red>>8]; |
| 2151 | png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >> |
| 2152 | png_ptr->gamma_shift][green>>8]; |
| 2153 | png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
| 2154 | png_ptr->gamma_shift][blue>>8]; |
| 2155 | png_uint_16 gray16 = (rc * red_1 + gc * green_1 |
| 2156 | + bc * blue_1)>>8; |
| 2157 | w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
| 2158 | png_ptr->gamma_shift][gray16 >> 8]; |
| 2159 | rgb_error |= 1; |
| 2160 | } |
| 2161 | |
| 2162 | *(dp++) = (w>>8) & 0xff; |
| 2163 | *(dp++) = w & 0xff; |
| 2164 | *(dp++) = *(sp++); /* alpha */ |
| 2165 | *(dp++) = *(sp++); |
| 2166 | } |
| 2167 | } |
| 2168 | else |
| 2169 | #endif |
| 2170 | { |
| 2171 | png_bytep sp = row; |
| 2172 | png_bytep dp = row; |
| 2173 | for (i = 0; i < row_width; i++) |
| 2174 | { |
| 2175 | png_uint_16 red, green, blue, gray16; |
| 2176 | red = (*(sp)<<8) | *(sp+1); sp+=2; |
| 2177 | green = (*(sp)<<8) | *(sp+1); sp+=2; |
| 2178 | blue = (*(sp)<<8) | *(sp+1); sp+=2; |
| 2179 | if(red != green || red != blue) |
| 2180 | rgb_error |= 1; |
| 2181 | gray16 = (rc * red + gc * green + bc * blue)>>8; |
| 2182 | *(dp++) = (gray16>>8) & 0xff; |
| 2183 | *(dp++) = gray16 & 0xff; |
| 2184 | *(dp++) = *(sp++); /* alpha */ |
| 2185 | *(dp++) = *(sp++); |
| 2186 | } |
| 2187 | } |
| 2188 | } |
| 2189 | } |
| 2190 | row_info->channels -= (png_byte)2; |
| 2191 | row_info->color_type &= ~PNG_COLOR_MASK_COLOR; |
| 2192 | row_info->pixel_depth = (png_byte)(row_info->channels * |
| 2193 | row_info->bit_depth); |
| 2194 | row_info->rowbytes = ((row_width * |
| 2195 | row_info->pixel_depth + 7) >> 3); |
| 2196 | } |
| 2197 | return rgb_error; |
| 2198 | } |
| 2199 | #endif |
| 2200 | |
| 2201 | /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth |
| 2202 | * large of png_color. This lets grayscale images be treated as |
| 2203 | * paletted. Most useful for gamma correction and simplification |
| 2204 | * of code. |
| 2205 | */ |
| 2206 | void |
| 2207 | png_build_grayscale_palette(int bit_depth, png_colorp palette) |
| 2208 | { |
| 2209 | int num_palette; |
| 2210 | int color_inc; |
| 2211 | int i; |
| 2212 | int v; |
| 2213 | |
| 2214 | png_debug(1, "in png_do_build_grayscale_palette\n"); |
| 2215 | if (palette == NULL) |
| 2216 | return; |
| 2217 | |
| 2218 | switch (bit_depth) |
| 2219 | { |
| 2220 | case 1: |
| 2221 | num_palette = 2; |
| 2222 | color_inc = 0xff; |
| 2223 | break; |
| 2224 | case 2: |
| 2225 | num_palette = 4; |
| 2226 | color_inc = 0x55; |
| 2227 | break; |
| 2228 | case 4: |
| 2229 | num_palette = 16; |
| 2230 | color_inc = 0x11; |
| 2231 | break; |
| 2232 | case 8: |
| 2233 | num_palette = 256; |
| 2234 | color_inc = 1; |
| 2235 | break; |
| 2236 | default: |
| 2237 | num_palette = 0; |
| 2238 | color_inc = 0; |
| 2239 | break; |
| 2240 | } |
| 2241 | |
| 2242 | for (i = 0, v = 0; i < num_palette; i++, v += color_inc) |
| 2243 | { |
| 2244 | palette[i].red = (png_byte)v; |
| 2245 | palette[i].green = (png_byte)v; |
| 2246 | palette[i].blue = (png_byte)v; |
| 2247 | } |
| 2248 | } |
| 2249 | |
| 2250 | /* This function is currently unused. Do we really need it? */ |
| 2251 | #if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED) |
| 2252 | void |
| 2253 | png_correct_palette(png_structp png_ptr, png_colorp palette, |
| 2254 | int num_palette) |
| 2255 | { |
| 2256 | png_debug(1, "in png_correct_palette\n"); |
| 2257 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) |
| 2258 | if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND)) |
| 2259 | { |
| 2260 | png_color back, back_1; |
| 2261 | |
| 2262 | if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
| 2263 | { |
| 2264 | back.red = png_ptr->gamma_table[png_ptr->background.red]; |
| 2265 | back.green = png_ptr->gamma_table[png_ptr->background.green]; |
| 2266 | back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
| 2267 | |
| 2268 | back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
| 2269 | back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
| 2270 | back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
| 2271 | } |
| 2272 | else |
| 2273 | { |
| 2274 | double g; |
| 2275 | |
| 2276 | g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma); |
| 2277 | |
| 2278 | if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN || |
| 2279 | fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) |
| 2280 | { |
| 2281 | back.red = png_ptr->background.red; |
| 2282 | back.green = png_ptr->background.green; |
| 2283 | back.blue = png_ptr->background.blue; |
| 2284 | } |
| 2285 | else |
| 2286 | { |
| 2287 | back.red = |
| 2288 | (png_byte)(pow((double)png_ptr->background.red/255, g) * |
| 2289 | 255.0 + 0.5); |
| 2290 | back.green = |
| 2291 | (png_byte)(pow((double)png_ptr->background.green/255, g) * |
| 2292 | 255.0 + 0.5); |
| 2293 | back.blue = |
| 2294 | (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
| 2295 | 255.0 + 0.5); |
| 2296 | } |
| 2297 | |
| 2298 | g = 1.0 / png_ptr->background_gamma; |
| 2299 | |
| 2300 | back_1.red = |
| 2301 | (png_byte)(pow((double)png_ptr->background.red/255, g) * |
| 2302 | 255.0 + 0.5); |
| 2303 | back_1.green = |
| 2304 | (png_byte)(pow((double)png_ptr->background.green/255, g) * |
| 2305 | 255.0 + 0.5); |
| 2306 | back_1.blue = |
| 2307 | (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
| 2308 | 255.0 + 0.5); |
| 2309 | } |
| 2310 | |
| 2311 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 2312 | { |
| 2313 | png_uint_32 i; |
| 2314 | |
| 2315 | for (i = 0; i < (png_uint_32)num_palette; i++) |
| 2316 | { |
| 2317 | if (i < png_ptr->num_trans && png_ptr->trans[i] == 0) |
| 2318 | { |
| 2319 | palette[i] = back; |
| 2320 | } |
| 2321 | else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
| 2322 | { |
| 2323 | png_byte v, w; |
| 2324 | |
| 2325 | v = png_ptr->gamma_to_1[png_ptr->palette[i].red]; |
| 2326 | png_composite(w, v, png_ptr->trans[i], back_1.red); |
| 2327 | palette[i].red = png_ptr->gamma_from_1[w]; |
| 2328 | |
| 2329 | v = png_ptr->gamma_to_1[png_ptr->palette[i].green]; |
| 2330 | png_composite(w, v, png_ptr->trans[i], back_1.green); |
| 2331 | palette[i].green = png_ptr->gamma_from_1[w]; |
| 2332 | |
| 2333 | v = png_ptr->gamma_to_1[png_ptr->palette[i].blue]; |
| 2334 | png_composite(w, v, png_ptr->trans[i], back_1.blue); |
| 2335 | palette[i].blue = png_ptr->gamma_from_1[w]; |
| 2336 | } |
| 2337 | else |
| 2338 | { |
| 2339 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| 2340 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| 2341 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| 2342 | } |
| 2343 | } |
| 2344 | } |
| 2345 | else |
| 2346 | { |
| 2347 | int i; |
| 2348 | |
| 2349 | for (i = 0; i < num_palette; i++) |
| 2350 | { |
| 2351 | if (palette[i].red == (png_byte)png_ptr->trans_values.gray) |
| 2352 | { |
| 2353 | palette[i] = back; |
| 2354 | } |
| 2355 | else |
| 2356 | { |
| 2357 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| 2358 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| 2359 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| 2360 | } |
| 2361 | } |
| 2362 | } |
| 2363 | } |
| 2364 | else |
| 2365 | #endif |
| 2366 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2367 | if (png_ptr->transformations & PNG_GAMMA) |
| 2368 | { |
| 2369 | int i; |
| 2370 | |
| 2371 | for (i = 0; i < num_palette; i++) |
| 2372 | { |
| 2373 | palette[i].red = png_ptr->gamma_table[palette[i].red]; |
| 2374 | palette[i].green = png_ptr->gamma_table[palette[i].green]; |
| 2375 | palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
| 2376 | } |
| 2377 | } |
| 2378 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 2379 | else |
| 2380 | #endif |
| 2381 | #endif |
| 2382 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 2383 | if (png_ptr->transformations & PNG_BACKGROUND) |
| 2384 | { |
| 2385 | if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
| 2386 | { |
| 2387 | png_color back; |
| 2388 | |
| 2389 | back.red = (png_byte)png_ptr->background.red; |
| 2390 | back.green = (png_byte)png_ptr->background.green; |
| 2391 | back.blue = (png_byte)png_ptr->background.blue; |
| 2392 | |
| 2393 | for (i = 0; i < (int)png_ptr->num_trans; i++) |
| 2394 | { |
| 2395 | if (png_ptr->trans[i] == 0) |
| 2396 | { |
| 2397 | palette[i].red = back.red; |
| 2398 | palette[i].green = back.green; |
| 2399 | palette[i].blue = back.blue; |
| 2400 | } |
| 2401 | else if (png_ptr->trans[i] != 0xff) |
| 2402 | { |
| 2403 | png_composite(palette[i].red, png_ptr->palette[i].red, |
| 2404 | png_ptr->trans[i], back.red); |
| 2405 | png_composite(palette[i].green, png_ptr->palette[i].green, |
| 2406 | png_ptr->trans[i], back.green); |
| 2407 | png_composite(palette[i].blue, png_ptr->palette[i].blue, |
| 2408 | png_ptr->trans[i], back.blue); |
| 2409 | } |
| 2410 | } |
| 2411 | } |
| 2412 | else /* assume grayscale palette (what else could it be?) */ |
| 2413 | { |
| 2414 | int i; |
| 2415 | |
| 2416 | for (i = 0; i < num_palette; i++) |
| 2417 | { |
| 2418 | if (i == (png_byte)png_ptr->trans_values.gray) |
| 2419 | { |
| 2420 | palette[i].red = (png_byte)png_ptr->background.red; |
| 2421 | palette[i].green = (png_byte)png_ptr->background.green; |
| 2422 | palette[i].blue = (png_byte)png_ptr->background.blue; |
| 2423 | } |
| 2424 | } |
| 2425 | } |
| 2426 | } |
| 2427 | #endif |
| 2428 | } |
| 2429 | #endif |
| 2430 | |
| 2431 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
| 2432 | /* Replace any alpha or transparency with the supplied background color. |
| 2433 | * "background" is already in the screen gamma, while "background_1" is |
| 2434 | * at a gamma of 1.0. Paletted files have already been taken care of. |
| 2435 | */ |
| 2436 | void |
| 2437 | png_do_background(png_row_infop row_info, png_bytep row, |
| 2438 | png_color_16p trans_values, png_color_16p background, |
| 2439 | png_color_16p background_1, |
| 2440 | png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1, |
| 2441 | png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1, |
| 2442 | png_uint_16pp gamma_16_to_1, int gamma_shift) |
| 2443 | { |
| 2444 | png_bytep sp, dp; |
| 2445 | png_uint_32 i; |
| 2446 | png_uint_32 row_width=row_info->width; |
| 2447 | int shift; |
| 2448 | |
| 2449 | png_debug(1, "in png_do_background\n"); |
| 2450 | if (background != NULL && |
| 2451 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 2452 | row != NULL && row_info != NULL && |
| 2453 | #endif |
| 2454 | (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) || |
| 2455 | (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values))) |
| 2456 | { |
| 2457 | switch (row_info->color_type) |
| 2458 | { |
| 2459 | case PNG_COLOR_TYPE_GRAY: |
| 2460 | { |
| 2461 | switch (row_info->bit_depth) |
| 2462 | { |
| 2463 | case 1: |
| 2464 | { |
| 2465 | sp = row; |
| 2466 | shift = 7; |
| 2467 | for (i = 0; i < row_width; i++) |
| 2468 | { |
| 2469 | if ((png_uint_16)((*sp >> shift) & 0x1) |
| 2470 | == trans_values->gray) |
| 2471 | { |
| 2472 | *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); |
| 2473 | *sp |= (png_byte)(background->gray << shift); |
| 2474 | } |
| 2475 | if (!shift) |
| 2476 | { |
| 2477 | shift = 7; |
| 2478 | sp++; |
| 2479 | } |
| 2480 | else |
| 2481 | shift--; |
| 2482 | } |
| 2483 | break; |
| 2484 | } |
| 2485 | case 2: |
| 2486 | { |
| 2487 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2488 | if (gamma_table != NULL) |
| 2489 | { |
| 2490 | sp = row; |
| 2491 | shift = 6; |
| 2492 | for (i = 0; i < row_width; i++) |
| 2493 | { |
| 2494 | if ((png_uint_16)((*sp >> shift) & 0x3) |
| 2495 | == trans_values->gray) |
| 2496 | { |
| 2497 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
| 2498 | *sp |= (png_byte)(background->gray << shift); |
| 2499 | } |
| 2500 | else |
| 2501 | { |
| 2502 | png_byte p = (*sp >> shift) & 0x3; |
| 2503 | png_byte g = (gamma_table [p | (p << 2) | (p << 4) | |
| 2504 | (p << 6)] >> 6) & 0x3; |
| 2505 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
| 2506 | *sp |= (png_byte)(g << shift); |
| 2507 | } |
| 2508 | if (!shift) |
| 2509 | { |
| 2510 | shift = 6; |
| 2511 | sp++; |
| 2512 | } |
| 2513 | else |
| 2514 | shift -= 2; |
| 2515 | } |
| 2516 | } |
| 2517 | else |
| 2518 | #endif |
| 2519 | { |
| 2520 | sp = row; |
| 2521 | shift = 6; |
| 2522 | for (i = 0; i < row_width; i++) |
| 2523 | { |
| 2524 | if ((png_uint_16)((*sp >> shift) & 0x3) |
| 2525 | == trans_values->gray) |
| 2526 | { |
| 2527 | *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
| 2528 | *sp |= (png_byte)(background->gray << shift); |
| 2529 | } |
| 2530 | if (!shift) |
| 2531 | { |
| 2532 | shift = 6; |
| 2533 | sp++; |
| 2534 | } |
| 2535 | else |
| 2536 | shift -= 2; |
| 2537 | } |
| 2538 | } |
| 2539 | break; |
| 2540 | } |
| 2541 | case 4: |
| 2542 | { |
| 2543 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2544 | if (gamma_table != NULL) |
| 2545 | { |
| 2546 | sp = row; |
| 2547 | shift = 4; |
| 2548 | for (i = 0; i < row_width; i++) |
| 2549 | { |
| 2550 | if ((png_uint_16)((*sp >> shift) & 0xf) |
| 2551 | == trans_values->gray) |
| 2552 | { |
| 2553 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
| 2554 | *sp |= (png_byte)(background->gray << shift); |
| 2555 | } |
| 2556 | else |
| 2557 | { |
| 2558 | png_byte p = (*sp >> shift) & 0xf; |
| 2559 | png_byte g = (gamma_table[p | (p << 4)] >> 4) & 0xf; |
| 2560 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
| 2561 | *sp |= (png_byte)(g << shift); |
| 2562 | } |
| 2563 | if (!shift) |
| 2564 | { |
| 2565 | shift = 4; |
| 2566 | sp++; |
| 2567 | } |
| 2568 | else |
| 2569 | shift -= 4; |
| 2570 | } |
| 2571 | } |
| 2572 | else |
| 2573 | #endif |
| 2574 | { |
| 2575 | sp = row; |
| 2576 | shift = 4; |
| 2577 | for (i = 0; i < row_width; i++) |
| 2578 | { |
| 2579 | if ((png_uint_16)((*sp >> shift) & 0xf) |
| 2580 | == trans_values->gray) |
| 2581 | { |
| 2582 | *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
| 2583 | *sp |= (png_byte)(background->gray << shift); |
| 2584 | } |
| 2585 | if (!shift) |
| 2586 | { |
| 2587 | shift = 4; |
| 2588 | sp++; |
| 2589 | } |
| 2590 | else |
| 2591 | shift -= 4; |
| 2592 | } |
| 2593 | } |
| 2594 | break; |
| 2595 | } |
| 2596 | case 8: |
| 2597 | { |
| 2598 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2599 | if (gamma_table != NULL) |
| 2600 | { |
| 2601 | sp = row; |
| 2602 | for (i = 0; i < row_width; i++, sp++) |
| 2603 | { |
| 2604 | if (*sp == trans_values->gray) |
| 2605 | { |
| 2606 | *sp = (png_byte)background->gray; |
| 2607 | } |
| 2608 | else |
| 2609 | { |
| 2610 | *sp = gamma_table[*sp]; |
| 2611 | } |
| 2612 | } |
| 2613 | } |
| 2614 | else |
| 2615 | #endif |
| 2616 | { |
| 2617 | sp = row; |
| 2618 | for (i = 0; i < row_width; i++, sp++) |
| 2619 | { |
| 2620 | if (*sp == trans_values->gray) |
| 2621 | { |
| 2622 | *sp = (png_byte)background->gray; |
| 2623 | } |
| 2624 | } |
| 2625 | } |
| 2626 | break; |
| 2627 | } |
| 2628 | case 16: |
| 2629 | { |
| 2630 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2631 | if (gamma_16 != NULL) |
| 2632 | { |
| 2633 | sp = row; |
| 2634 | for (i = 0; i < row_width; i++, sp += 2) |
| 2635 | { |
| 2636 | png_uint_16 v; |
| 2637 | |
| 2638 | v = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| 2639 | if (v == trans_values->gray) |
| 2640 | { |
| 2641 | /* background is already in screen gamma */ |
| 2642 | *sp = (png_byte)((background->gray >> 8) & 0xff); |
| 2643 | *(sp + 1) = (png_byte)(background->gray & 0xff); |
| 2644 | } |
| 2645 | else |
| 2646 | { |
| 2647 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
| 2648 | *sp = (png_byte)((v >> 8) & 0xff); |
| 2649 | *(sp + 1) = (png_byte)(v & 0xff); |
| 2650 | } |
| 2651 | } |
| 2652 | } |
| 2653 | else |
| 2654 | #endif |
| 2655 | { |
| 2656 | sp = row; |
| 2657 | for (i = 0; i < row_width; i++, sp += 2) |
| 2658 | { |
| 2659 | png_uint_16 v; |
| 2660 | |
| 2661 | v = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| 2662 | if (v == trans_values->gray) |
| 2663 | { |
| 2664 | *sp = (png_byte)((background->gray >> 8) & 0xff); |
| 2665 | *(sp + 1) = (png_byte)(background->gray & 0xff); |
| 2666 | } |
| 2667 | } |
| 2668 | } |
| 2669 | break; |
| 2670 | } |
| 2671 | } |
| 2672 | break; |
| 2673 | } |
| 2674 | case PNG_COLOR_TYPE_RGB: |
| 2675 | { |
| 2676 | if (row_info->bit_depth == 8) |
| 2677 | { |
| 2678 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2679 | if (gamma_table != NULL) |
| 2680 | { |
| 2681 | sp = row; |
| 2682 | for (i = 0; i < row_width; i++, sp += 3) |
| 2683 | { |
| 2684 | if (*sp == trans_values->red && |
| 2685 | *(sp + 1) == trans_values->green && |
| 2686 | *(sp + 2) == trans_values->blue) |
| 2687 | { |
| 2688 | *sp = (png_byte)background->red; |
| 2689 | *(sp + 1) = (png_byte)background->green; |
| 2690 | *(sp + 2) = (png_byte)background->blue; |
| 2691 | } |
| 2692 | else |
| 2693 | { |
| 2694 | *sp = gamma_table[*sp]; |
| 2695 | *(sp + 1) = gamma_table[*(sp + 1)]; |
| 2696 | *(sp + 2) = gamma_table[*(sp + 2)]; |
| 2697 | } |
| 2698 | } |
| 2699 | } |
| 2700 | else |
| 2701 | #endif |
| 2702 | { |
| 2703 | sp = row; |
| 2704 | for (i = 0; i < row_width; i++, sp += 3) |
| 2705 | { |
| 2706 | if (*sp == trans_values->red && |
| 2707 | *(sp + 1) == trans_values->green && |
| 2708 | *(sp + 2) == trans_values->blue) |
| 2709 | { |
| 2710 | *sp = (png_byte)background->red; |
| 2711 | *(sp + 1) = (png_byte)background->green; |
| 2712 | *(sp + 2) = (png_byte)background->blue; |
| 2713 | } |
| 2714 | } |
| 2715 | } |
| 2716 | } |
| 2717 | else /* if (row_info->bit_depth == 16) */ |
| 2718 | { |
| 2719 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2720 | if (gamma_16 != NULL) |
| 2721 | { |
| 2722 | sp = row; |
| 2723 | for (i = 0; i < row_width; i++, sp += 6) |
| 2724 | { |
| 2725 | png_uint_16 r = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| 2726 | png_uint_16 g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); |
| 2727 | png_uint_16 b = ((png_uint_16)(*(sp + 4)) << 8) + *(sp + 5); |
| 2728 | if (r == trans_values->red && g == trans_values->green && |
| 2729 | b == trans_values->blue) |
| 2730 | { |
| 2731 | /* background is already in screen gamma */ |
| 2732 | *sp = (png_byte)((background->red >> 8) & 0xff); |
| 2733 | *(sp + 1) = (png_byte)(background->red & 0xff); |
| 2734 | *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); |
| 2735 | *(sp + 3) = (png_byte)(background->green & 0xff); |
| 2736 | *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
| 2737 | *(sp + 5) = (png_byte)(background->blue & 0xff); |
| 2738 | } |
| 2739 | else |
| 2740 | { |
| 2741 | png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
| 2742 | *sp = (png_byte)((v >> 8) & 0xff); |
| 2743 | *(sp + 1) = (png_byte)(v & 0xff); |
| 2744 | v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
| 2745 | *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
| 2746 | *(sp + 3) = (png_byte)(v & 0xff); |
| 2747 | v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
| 2748 | *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
| 2749 | *(sp + 5) = (png_byte)(v & 0xff); |
| 2750 | } |
| 2751 | } |
| 2752 | } |
| 2753 | else |
| 2754 | #endif |
| 2755 | { |
| 2756 | sp = row; |
| 2757 | for (i = 0; i < row_width; i++, sp += 6) |
| 2758 | { |
| 2759 | png_uint_16 r = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| 2760 | png_uint_16 g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); |
| 2761 | png_uint_16 b = ((png_uint_16)(*(sp + 4)) << 8) + *(sp + 5); |
| 2762 | |
| 2763 | if (r == trans_values->red && g == trans_values->green && |
| 2764 | b == trans_values->blue) |
| 2765 | { |
| 2766 | *sp = (png_byte)((background->red >> 8) & 0xff); |
| 2767 | *(sp + 1) = (png_byte)(background->red & 0xff); |
| 2768 | *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); |
| 2769 | *(sp + 3) = (png_byte)(background->green & 0xff); |
| 2770 | *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
| 2771 | *(sp + 5) = (png_byte)(background->blue & 0xff); |
| 2772 | } |
| 2773 | } |
| 2774 | } |
| 2775 | } |
| 2776 | break; |
| 2777 | } |
| 2778 | case PNG_COLOR_TYPE_GRAY_ALPHA: |
| 2779 | { |
| 2780 | if (row_info->bit_depth == 8) |
| 2781 | { |
| 2782 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2783 | if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
| 2784 | gamma_table != NULL) |
| 2785 | { |
| 2786 | sp = row; |
| 2787 | dp = row; |
| 2788 | for (i = 0; i < row_width; i++, sp += 2, dp++) |
| 2789 | { |
| 2790 | png_uint_16 a = *(sp + 1); |
| 2791 | |
| 2792 | if (a == 0xff) |
| 2793 | { |
| 2794 | *dp = gamma_table[*sp]; |
| 2795 | } |
| 2796 | else if (a == 0) |
| 2797 | { |
| 2798 | /* background is already in screen gamma */ |
| 2799 | *dp = (png_byte)background->gray; |
| 2800 | } |
| 2801 | else |
| 2802 | { |
| 2803 | png_byte v, w; |
| 2804 | |
| 2805 | v = gamma_to_1[*sp]; |
| 2806 | png_composite(w, v, a, background_1->gray); |
| 2807 | *dp = gamma_from_1[w]; |
| 2808 | } |
| 2809 | } |
| 2810 | } |
| 2811 | else |
| 2812 | #endif |
| 2813 | { |
| 2814 | sp = row; |
| 2815 | dp = row; |
| 2816 | for (i = 0; i < row_width; i++, sp += 2, dp++) |
| 2817 | { |
| 2818 | png_byte a = *(sp + 1); |
| 2819 | |
| 2820 | if (a == 0xff) |
| 2821 | { |
| 2822 | *dp = *sp; |
| 2823 | } |
| 2824 | else if (a == 0) |
| 2825 | { |
| 2826 | *dp = (png_byte)background->gray; |
| 2827 | } |
| 2828 | else |
| 2829 | { |
| 2830 | png_composite(*dp, *sp, a, background_1->gray); |
| 2831 | } |
| 2832 | } |
| 2833 | } |
| 2834 | } |
| 2835 | else /* if (png_ptr->bit_depth == 16) */ |
| 2836 | { |
| 2837 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2838 | if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
| 2839 | gamma_16_to_1 != NULL) |
| 2840 | { |
| 2841 | sp = row; |
| 2842 | dp = row; |
| 2843 | for (i = 0; i < row_width; i++, sp += 4, dp += 2) |
| 2844 | { |
| 2845 | png_uint_16 a = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); |
| 2846 | |
| 2847 | if (a == (png_uint_16)0xffff) |
| 2848 | { |
| 2849 | png_uint_16 v; |
| 2850 | |
| 2851 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
| 2852 | *dp = (png_byte)((v >> 8) & 0xff); |
| 2853 | *(dp + 1) = (png_byte)(v & 0xff); |
| 2854 | } |
| 2855 | else if (a == 0) |
| 2856 | { |
| 2857 | /* background is already in screen gamma */ |
| 2858 | *dp = (png_byte)((background->gray >> 8) & 0xff); |
| 2859 | *(dp + 1) = (png_byte)(background->gray & 0xff); |
| 2860 | } |
| 2861 | else |
| 2862 | { |
| 2863 | png_uint_16 g, v, w; |
| 2864 | |
| 2865 | g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
| 2866 | png_composite_16(v, g, a, background_1->gray); |
| 2867 | w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; |
| 2868 | *dp = (png_byte)((w >> 8) & 0xff); |
| 2869 | *(dp + 1) = (png_byte)(w & 0xff); |
| 2870 | } |
| 2871 | } |
| 2872 | } |
| 2873 | else |
| 2874 | #endif |
| 2875 | { |
| 2876 | sp = row; |
| 2877 | dp = row; |
| 2878 | for (i = 0; i < row_width; i++, sp += 4, dp += 2) |
| 2879 | { |
| 2880 | png_uint_16 a = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); |
| 2881 | if (a == (png_uint_16)0xffff) |
| 2882 | { |
| 2883 | png_memcpy(dp, sp, 2); |
| 2884 | } |
| 2885 | else if (a == 0) |
| 2886 | { |
| 2887 | *dp = (png_byte)((background->gray >> 8) & 0xff); |
| 2888 | *(dp + 1) = (png_byte)(background->gray & 0xff); |
| 2889 | } |
| 2890 | else |
| 2891 | { |
| 2892 | png_uint_16 g, v; |
| 2893 | |
| 2894 | g = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| 2895 | png_composite_16(v, g, a, background_1->gray); |
| 2896 | *dp = (png_byte)((v >> 8) & 0xff); |
| 2897 | *(dp + 1) = (png_byte)(v & 0xff); |
| 2898 | } |
| 2899 | } |
| 2900 | } |
| 2901 | } |
| 2902 | break; |
| 2903 | } |
| 2904 | case PNG_COLOR_TYPE_RGB_ALPHA: |
| 2905 | { |
| 2906 | if (row_info->bit_depth == 8) |
| 2907 | { |
| 2908 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2909 | if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
| 2910 | gamma_table != NULL) |
| 2911 | { |
| 2912 | sp = row; |
| 2913 | dp = row; |
| 2914 | for (i = 0; i < row_width; i++, sp += 4, dp += 3) |
| 2915 | { |
| 2916 | png_byte a = *(sp + 3); |
| 2917 | |
| 2918 | if (a == 0xff) |
| 2919 | { |
| 2920 | *dp = gamma_table[*sp]; |
| 2921 | *(dp + 1) = gamma_table[*(sp + 1)]; |
| 2922 | *(dp + 2) = gamma_table[*(sp + 2)]; |
| 2923 | } |
| 2924 | else if (a == 0) |
| 2925 | { |
| 2926 | /* background is already in screen gamma */ |
| 2927 | *dp = (png_byte)background->red; |
| 2928 | *(dp + 1) = (png_byte)background->green; |
| 2929 | *(dp + 2) = (png_byte)background->blue; |
| 2930 | } |
| 2931 | else |
| 2932 | { |
| 2933 | png_byte v, w; |
| 2934 | |
| 2935 | v = gamma_to_1[*sp]; |
| 2936 | png_composite(w, v, a, background_1->red); |
| 2937 | *dp = gamma_from_1[w]; |
| 2938 | v = gamma_to_1[*(sp + 1)]; |
| 2939 | png_composite(w, v, a, background_1->green); |
| 2940 | *(dp + 1) = gamma_from_1[w]; |
| 2941 | v = gamma_to_1[*(sp + 2)]; |
| 2942 | png_composite(w, v, a, background_1->blue); |
| 2943 | *(dp + 2) = gamma_from_1[w]; |
| 2944 | } |
| 2945 | } |
| 2946 | } |
| 2947 | else |
| 2948 | #endif |
| 2949 | { |
| 2950 | sp = row; |
| 2951 | dp = row; |
| 2952 | for (i = 0; i < row_width; i++, sp += 4, dp += 3) |
| 2953 | { |
| 2954 | png_byte a = *(sp + 3); |
| 2955 | |
| 2956 | if (a == 0xff) |
| 2957 | { |
| 2958 | *dp = *sp; |
| 2959 | *(dp + 1) = *(sp + 1); |
| 2960 | *(dp + 2) = *(sp + 2); |
| 2961 | } |
| 2962 | else if (a == 0) |
| 2963 | { |
| 2964 | *dp = (png_byte)background->red; |
| 2965 | *(dp + 1) = (png_byte)background->green; |
| 2966 | *(dp + 2) = (png_byte)background->blue; |
| 2967 | } |
| 2968 | else |
| 2969 | { |
| 2970 | png_composite(*dp, *sp, a, background->red); |
| 2971 | png_composite(*(dp + 1), *(sp + 1), a, |
| 2972 | background->green); |
| 2973 | png_composite(*(dp + 2), *(sp + 2), a, |
| 2974 | background->blue); |
| 2975 | } |
| 2976 | } |
| 2977 | } |
| 2978 | } |
| 2979 | else /* if (row_info->bit_depth == 16) */ |
| 2980 | { |
| 2981 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 2982 | if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
| 2983 | gamma_16_to_1 != NULL) |
| 2984 | { |
| 2985 | sp = row; |
| 2986 | dp = row; |
| 2987 | for (i = 0; i < row_width; i++, sp += 8, dp += 6) |
| 2988 | { |
| 2989 | png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
| 2990 | << 8) + (png_uint_16)(*(sp + 7))); |
| 2991 | if (a == (png_uint_16)0xffff) |
| 2992 | { |
| 2993 | png_uint_16 v; |
| 2994 | |
| 2995 | v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
| 2996 | *dp = (png_byte)((v >> 8) & 0xff); |
| 2997 | *(dp + 1) = (png_byte)(v & 0xff); |
| 2998 | v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
| 2999 | *(dp + 2) = (png_byte)((v >> 8) & 0xff); |
| 3000 | *(dp + 3) = (png_byte)(v & 0xff); |
| 3001 | v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
| 3002 | *(dp + 4) = (png_byte)((v >> 8) & 0xff); |
| 3003 | *(dp + 5) = (png_byte)(v & 0xff); |
| 3004 | } |
| 3005 | else if (a == 0) |
| 3006 | { |
| 3007 | /* background is already in screen gamma */ |
| 3008 | *dp = (png_byte)((background->red >> 8) & 0xff); |
| 3009 | *(dp + 1) = (png_byte)(background->red & 0xff); |
| 3010 | *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); |
| 3011 | *(dp + 3) = (png_byte)(background->green & 0xff); |
| 3012 | *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
| 3013 | *(dp + 5) = (png_byte)(background->blue & 0xff); |
| 3014 | } |
| 3015 | else |
| 3016 | { |
| 3017 | png_uint_16 v, w, x; |
| 3018 | |
| 3019 | v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
| 3020 | png_composite_16(w, v, a, background->red); |
| 3021 | x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
| 3022 | *dp = (png_byte)((x >> 8) & 0xff); |
| 3023 | *(dp + 1) = (png_byte)(x & 0xff); |
| 3024 | v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
| 3025 | png_composite_16(w, v, a, background->green); |
| 3026 | x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
| 3027 | *(dp + 2) = (png_byte)((x >> 8) & 0xff); |
| 3028 | *(dp + 3) = (png_byte)(x & 0xff); |
| 3029 | v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
| 3030 | png_composite_16(w, v, a, background->blue); |
| 3031 | x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8]; |
| 3032 | *(dp + 4) = (png_byte)((x >> 8) & 0xff); |
| 3033 | *(dp + 5) = (png_byte)(x & 0xff); |
| 3034 | } |
| 3035 | } |
| 3036 | } |
| 3037 | else |
| 3038 | #endif |
| 3039 | { |
| 3040 | sp = row; |
| 3041 | dp = row; |
| 3042 | for (i = 0; i < row_width; i++, sp += 8, dp += 6) |
| 3043 | { |
| 3044 | png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
| 3045 | << 8) + (png_uint_16)(*(sp + 7))); |
| 3046 | if (a == (png_uint_16)0xffff) |
| 3047 | { |
| 3048 | png_memcpy(dp, sp, 6); |
| 3049 | } |
| 3050 | else if (a == 0) |
| 3051 | { |
| 3052 | *dp = (png_byte)((background->red >> 8) & 0xff); |
| 3053 | *(dp + 1) = (png_byte)(background->red & 0xff); |
| 3054 | *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); |
| 3055 | *(dp + 3) = (png_byte)(background->green & 0xff); |
| 3056 | *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
| 3057 | *(dp + 5) = (png_byte)(background->blue & 0xff); |
| 3058 | } |
| 3059 | else |
| 3060 | { |
| 3061 | png_uint_16 v; |
| 3062 | |
| 3063 | png_uint_16 r = ((png_uint_16)(*sp) << 8) + *(sp + 1); |
| 3064 | png_uint_16 g = ((png_uint_16)(*(sp + 2)) << 8) |
| 3065 | + *(sp + 3); |
| 3066 | png_uint_16 b = ((png_uint_16)(*(sp + 4)) << 8) |
| 3067 | + *(sp + 5); |
| 3068 | |
| 3069 | png_composite_16(v, r, a, background->red); |
| 3070 | *dp = (png_byte)((v >> 8) & 0xff); |
| 3071 | *(dp + 1) = (png_byte)(v & 0xff); |
| 3072 | png_composite_16(v, g, a, background->green); |
| 3073 | *(dp + 2) = (png_byte)((v >> 8) & 0xff); |
| 3074 | *(dp + 3) = (png_byte)(v & 0xff); |
| 3075 | png_composite_16(v, b, a, background->blue); |
| 3076 | *(dp + 4) = (png_byte)((v >> 8) & 0xff); |
| 3077 | *(dp + 5) = (png_byte)(v & 0xff); |
| 3078 | } |
| 3079 | } |
| 3080 | } |
| 3081 | } |
| 3082 | break; |
| 3083 | } |
| 3084 | } |
| 3085 | |
| 3086 | if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
| 3087 | { |
| 3088 | row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; |
| 3089 | row_info->channels--; |
| 3090 | row_info->pixel_depth = (png_byte)(row_info->channels * |
| 3091 | row_info->bit_depth); |
| 3092 | row_info->rowbytes = ((row_width * |
| 3093 | row_info->pixel_depth + 7) >> 3); |
| 3094 | } |
| 3095 | } |
| 3096 | } |
| 3097 | #endif |
| 3098 | |
| 3099 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 3100 | /* Gamma correct the image, avoiding the alpha channel. Make sure |
| 3101 | * you do this after you deal with the transparency issue on grayscale |
| 3102 | * or rgb images. If your bit depth is 8, use gamma_table, if it |
| 3103 | * is 16, use gamma_16_table and gamma_shift. Build these with |
| 3104 | * build_gamma_table(). |
| 3105 | */ |
| 3106 | void |
| 3107 | png_do_gamma(png_row_infop row_info, png_bytep row, |
| 3108 | png_bytep gamma_table, png_uint_16pp gamma_16_table, |
| 3109 | int gamma_shift) |
| 3110 | { |
| 3111 | png_bytep sp; |
| 3112 | png_uint_32 i; |
| 3113 | png_uint_32 row_width=row_info->width; |
| 3114 | |
| 3115 | png_debug(1, "in png_do_gamma\n"); |
| 3116 | if ( |
| 3117 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 3118 | row != NULL && row_info != NULL && |
| 3119 | #endif |
| 3120 | ((row_info->bit_depth <= 8 && gamma_table != NULL) || |
| 3121 | (row_info->bit_depth == 16 && gamma_16_table != NULL))) |
| 3122 | { |
| 3123 | switch (row_info->color_type) |
| 3124 | { |
| 3125 | case PNG_COLOR_TYPE_RGB: |
| 3126 | { |
| 3127 | if (row_info->bit_depth == 8) |
| 3128 | { |
| 3129 | sp = row; |
| 3130 | for (i = 0; i < row_width; i++) |
| 3131 | { |
| 3132 | *sp = gamma_table[*sp]; |
| 3133 | sp++; |
| 3134 | *sp = gamma_table[*sp]; |
| 3135 | sp++; |
| 3136 | *sp = gamma_table[*sp]; |
| 3137 | sp++; |
| 3138 | } |
| 3139 | } |
| 3140 | else /* if (row_info->bit_depth == 16) */ |
| 3141 | { |
| 3142 | sp = row; |
| 3143 | for (i = 0; i < row_width; i++) |
| 3144 | { |
| 3145 | png_uint_16 v; |
| 3146 | |
| 3147 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| 3148 | *sp = (png_byte)((v >> 8) & 0xff); |
| 3149 | *(sp + 1) = (png_byte)(v & 0xff); |
| 3150 | sp += 2; |
| 3151 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| 3152 | *sp = (png_byte)((v >> 8) & 0xff); |
| 3153 | *(sp + 1) = (png_byte)(v & 0xff); |
| 3154 | sp += 2; |
| 3155 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| 3156 | *sp = (png_byte)((v >> 8) & 0xff); |
| 3157 | *(sp + 1) = (png_byte)(v & 0xff); |
| 3158 | sp += 2; |
| 3159 | } |
| 3160 | } |
| 3161 | break; |
| 3162 | } |
| 3163 | case PNG_COLOR_TYPE_RGB_ALPHA: |
| 3164 | { |
| 3165 | if (row_info->bit_depth == 8) |
| 3166 | { |
| 3167 | sp = row; |
| 3168 | for (i = 0; i < row_width; i++) |
| 3169 | { |
| 3170 | *sp = gamma_table[*sp]; |
| 3171 | sp++; |
| 3172 | *sp = gamma_table[*sp]; |
| 3173 | sp++; |
| 3174 | *sp = gamma_table[*sp]; |
| 3175 | sp++; |
| 3176 | sp++; |
| 3177 | } |
| 3178 | } |
| 3179 | else /* if (row_info->bit_depth == 16) */ |
| 3180 | { |
| 3181 | sp = row; |
| 3182 | for (i = 0; i < row_width; i++) |
| 3183 | { |
| 3184 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| 3185 | *sp = (png_byte)((v >> 8) & 0xff); |
| 3186 | *(sp + 1) = (png_byte)(v & 0xff); |
| 3187 | sp += 2; |
| 3188 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| 3189 | *sp = (png_byte)((v >> 8) & 0xff); |
| 3190 | *(sp + 1) = (png_byte)(v & 0xff); |
| 3191 | sp += 2; |
| 3192 | v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| 3193 | *sp = (png_byte)((v >> 8) & 0xff); |
| 3194 | *(sp + 1) = (png_byte)(v & 0xff); |
| 3195 | sp += 4; |
| 3196 | } |
| 3197 | } |
| 3198 | break; |
| 3199 | } |
| 3200 | case PNG_COLOR_TYPE_GRAY_ALPHA: |
| 3201 | { |
| 3202 | if (row_info->bit_depth == 8) |
| 3203 | { |
| 3204 | sp = row; |
| 3205 | for (i = 0; i < row_width; i++) |
| 3206 | { |
| 3207 | *sp = gamma_table[*sp]; |
| 3208 | sp += 2; |
| 3209 | } |
| 3210 | } |
| 3211 | else /* if (row_info->bit_depth == 16) */ |
| 3212 | { |
| 3213 | sp = row; |
| 3214 | for (i = 0; i < row_width; i++) |
| 3215 | { |
| 3216 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| 3217 | *sp = (png_byte)((v >> 8) & 0xff); |
| 3218 | *(sp + 1) = (png_byte)(v & 0xff); |
| 3219 | sp += 4; |
| 3220 | } |
| 3221 | } |
| 3222 | break; |
| 3223 | } |
| 3224 | case PNG_COLOR_TYPE_GRAY: |
| 3225 | { |
| 3226 | if (row_info->bit_depth == 2) |
| 3227 | { |
| 3228 | sp = row; |
| 3229 | for (i = 0; i < row_width; i += 4) |
| 3230 | { |
| 3231 | int a = *sp & 0xc0; |
| 3232 | int b = *sp & 0x30; |
| 3233 | int c = *sp & 0x0c; |
| 3234 | int d = *sp & 0x03; |
| 3235 | |
| 3236 | *sp = ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| |
| 3237 | ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| |
| 3238 | ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| |
| 3239 | ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ); |
| 3240 | sp++; |
| 3241 | } |
| 3242 | } |
| 3243 | if (row_info->bit_depth == 4) |
| 3244 | { |
| 3245 | sp = row; |
| 3246 | for (i = 0; i < row_width; i += 2) |
| 3247 | { |
| 3248 | int msb = *sp & 0xf0; |
| 3249 | int lsb = *sp & 0x0f; |
| 3250 | |
| 3251 | *sp = (((int)gamma_table[msb | (msb >> 4)]) & 0xf0) | |
| 3252 | (((int)gamma_table[(lsb << 4) | lsb]) >> 4); |
| 3253 | sp++; |
| 3254 | } |
| 3255 | } |
| 3256 | else if (row_info->bit_depth == 8) |
| 3257 | { |
| 3258 | sp = row; |
| 3259 | for (i = 0; i < row_width; i++) |
| 3260 | { |
| 3261 | *sp = gamma_table[*sp]; |
| 3262 | sp++; |
| 3263 | } |
| 3264 | } |
| 3265 | else if (row_info->bit_depth == 16) |
| 3266 | { |
| 3267 | sp = row; |
| 3268 | for (i = 0; i < row_width; i++) |
| 3269 | { |
| 3270 | png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
| 3271 | *sp = (png_byte)((v >> 8) & 0xff); |
| 3272 | *(sp + 1) = (png_byte)(v & 0xff); |
| 3273 | sp += 2; |
| 3274 | } |
| 3275 | } |
| 3276 | break; |
| 3277 | } |
| 3278 | } |
| 3279 | } |
| 3280 | } |
| 3281 | #endif |
| 3282 | |
| 3283 | #if defined(PNG_READ_EXPAND_SUPPORTED) |
| 3284 | /* Expands a palette row to an rgb or rgba row depending |
| 3285 | * upon whether you supply trans and num_trans. |
| 3286 | */ |
| 3287 | void |
| 3288 | png_do_expand_palette(png_row_infop row_info, png_bytep row, |
| 3289 | png_colorp palette, png_bytep trans, int num_trans) |
| 3290 | { |
| 3291 | int shift, value; |
| 3292 | png_bytep sp, dp; |
| 3293 | png_uint_32 i; |
| 3294 | png_uint_32 row_width=row_info->width; |
| 3295 | |
| 3296 | png_debug(1, "in png_do_expand_palette\n"); |
| 3297 | if ( |
| 3298 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 3299 | row != NULL && row_info != NULL && |
| 3300 | #endif |
| 3301 | row_info->color_type == PNG_COLOR_TYPE_PALETTE) |
| 3302 | { |
| 3303 | if (row_info->bit_depth < 8) |
| 3304 | { |
| 3305 | switch (row_info->bit_depth) |
| 3306 | { |
| 3307 | case 1: |
| 3308 | { |
| 3309 | sp = row + (png_size_t)((row_width - 1) >> 3); |
| 3310 | dp = row + (png_size_t)row_width - 1; |
| 3311 | shift = 7 - (int)((row_width + 7) & 7); |
| 3312 | for (i = 0; i < row_width; i++) |
| 3313 | { |
| 3314 | if ((*sp >> shift) & 0x1) |
| 3315 | *dp = 1; |
| 3316 | else |
| 3317 | *dp = 0; |
| 3318 | if (shift == 7) |
| 3319 | { |
| 3320 | shift = 0; |
| 3321 | sp--; |
| 3322 | } |
| 3323 | else |
| 3324 | shift++; |
| 3325 | |
| 3326 | dp--; |
| 3327 | } |
| 3328 | break; |
| 3329 | } |
| 3330 | case 2: |
| 3331 | { |
| 3332 | sp = row + (png_size_t)((row_width - 1) >> 2); |
| 3333 | dp = row + (png_size_t)row_width - 1; |
| 3334 | shift = (int)((3 - ((row_width + 3) & 3)) << 1); |
| 3335 | for (i = 0; i < row_width; i++) |
| 3336 | { |
| 3337 | value = (*sp >> shift) & 0x3; |
| 3338 | *dp = (png_byte)value; |
| 3339 | if (shift == 6) |
| 3340 | { |
| 3341 | shift = 0; |
| 3342 | sp--; |
| 3343 | } |
| 3344 | else |
| 3345 | shift += 2; |
| 3346 | |
| 3347 | dp--; |
| 3348 | } |
| 3349 | break; |
| 3350 | } |
| 3351 | case 4: |
| 3352 | { |
| 3353 | sp = row + (png_size_t)((row_width - 1) >> 1); |
| 3354 | dp = row + (png_size_t)row_width - 1; |
| 3355 | shift = (int)((row_width & 1) << 2); |
| 3356 | for (i = 0; i < row_width; i++) |
| 3357 | { |
| 3358 | value = (*sp >> shift) & 0xf; |
| 3359 | *dp = (png_byte)value; |
| 3360 | if (shift == 4) |
| 3361 | { |
| 3362 | shift = 0; |
| 3363 | sp--; |
| 3364 | } |
| 3365 | else |
| 3366 | shift += 4; |
| 3367 | |
| 3368 | dp--; |
| 3369 | } |
| 3370 | break; |
| 3371 | } |
| 3372 | } |
| 3373 | row_info->bit_depth = 8; |
| 3374 | row_info->pixel_depth = 8; |
| 3375 | row_info->rowbytes = row_width; |
| 3376 | } |
| 3377 | switch (row_info->bit_depth) |
| 3378 | { |
| 3379 | case 8: |
| 3380 | { |
| 3381 | if (trans != NULL) |
| 3382 | { |
| 3383 | sp = row + (png_size_t)row_width - 1; |
| 3384 | dp = row + (png_size_t)(row_width << 2) - 1; |
| 3385 | |
| 3386 | for (i = 0; i < row_width; i++) |
| 3387 | { |
| 3388 | if ((int)(*sp) >= num_trans) |
| 3389 | *dp-- = 0xff; |
| 3390 | else |
| 3391 | *dp-- = trans[*sp]; |
| 3392 | *dp-- = palette[*sp].blue; |
| 3393 | *dp-- = palette[*sp].green; |
| 3394 | *dp-- = palette[*sp].red; |
| 3395 | sp--; |
| 3396 | } |
| 3397 | row_info->bit_depth = 8; |
| 3398 | row_info->pixel_depth = 32; |
| 3399 | row_info->rowbytes = row_width * 4; |
| 3400 | row_info->color_type = 6; |
| 3401 | row_info->channels = 4; |
| 3402 | } |
| 3403 | else |
| 3404 | { |
| 3405 | sp = row + (png_size_t)row_width - 1; |
| 3406 | dp = row + (png_size_t)(row_width * 3) - 1; |
| 3407 | |
| 3408 | for (i = 0; i < row_width; i++) |
| 3409 | { |
| 3410 | *dp-- = palette[*sp].blue; |
| 3411 | *dp-- = palette[*sp].green; |
| 3412 | *dp-- = palette[*sp].red; |
| 3413 | sp--; |
| 3414 | } |
| 3415 | row_info->bit_depth = 8; |
| 3416 | row_info->pixel_depth = 24; |
| 3417 | row_info->rowbytes = row_width * 3; |
| 3418 | row_info->color_type = 2; |
| 3419 | row_info->channels = 3; |
| 3420 | } |
| 3421 | break; |
| 3422 | } |
| 3423 | } |
| 3424 | } |
| 3425 | } |
| 3426 | |
| 3427 | /* If the bit depth < 8, it is expanded to 8. Also, if the |
| 3428 | * transparency value is supplied, an alpha channel is built. |
| 3429 | */ |
| 3430 | void |
| 3431 | png_do_expand(png_row_infop row_info, png_bytep row, |
| 3432 | png_color_16p trans_value) |
| 3433 | { |
| 3434 | int shift, value; |
| 3435 | png_bytep sp, dp; |
| 3436 | png_uint_32 i; |
| 3437 | png_uint_32 row_width=row_info->width; |
| 3438 | |
| 3439 | png_debug(1, "in png_do_expand\n"); |
| 3440 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 3441 | if (row != NULL && row_info != NULL) |
| 3442 | #endif |
| 3443 | { |
| 3444 | if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
| 3445 | { |
| 3446 | png_uint_16 gray = trans_value ? trans_value->gray : 0; |
| 3447 | |
| 3448 | if (row_info->bit_depth < 8) |
| 3449 | { |
| 3450 | switch (row_info->bit_depth) |
| 3451 | { |
| 3452 | case 1: |
| 3453 | { |
| 3454 | gray *= 0xff; |
| 3455 | sp = row + (png_size_t)((row_width - 1) >> 3); |
| 3456 | dp = row + (png_size_t)row_width - 1; |
| 3457 | shift = 7 - (int)((row_width + 7) & 7); |
| 3458 | for (i = 0; i < row_width; i++) |
| 3459 | { |
| 3460 | if ((*sp >> shift) & 0x1) |
| 3461 | *dp = 0xff; |
| 3462 | else |
| 3463 | *dp = 0; |
| 3464 | if (shift == 7) |
| 3465 | { |
| 3466 | shift = 0; |
| 3467 | sp--; |
| 3468 | } |
| 3469 | else |
| 3470 | shift++; |
| 3471 | |
| 3472 | dp--; |
| 3473 | } |
| 3474 | break; |
| 3475 | } |
| 3476 | case 2: |
| 3477 | { |
| 3478 | gray *= 0x55; |
| 3479 | sp = row + (png_size_t)((row_width - 1) >> 2); |
| 3480 | dp = row + (png_size_t)row_width - 1; |
| 3481 | shift = (int)((3 - ((row_width + 3) & 3)) << 1); |
| 3482 | for (i = 0; i < row_width; i++) |
| 3483 | { |
| 3484 | value = (*sp >> shift) & 0x3; |
| 3485 | *dp = (png_byte)(value | (value << 2) | (value << 4) | |
| 3486 | (value << 6)); |
| 3487 | if (shift == 6) |
| 3488 | { |
| 3489 | shift = 0; |
| 3490 | sp--; |
| 3491 | } |
| 3492 | else |
| 3493 | shift += 2; |
| 3494 | |
| 3495 | dp--; |
| 3496 | } |
| 3497 | break; |
| 3498 | } |
| 3499 | case 4: |
| 3500 | { |
| 3501 | gray *= 0x11; |
| 3502 | sp = row + (png_size_t)((row_width - 1) >> 1); |
| 3503 | dp = row + (png_size_t)row_width - 1; |
| 3504 | shift = (int)((1 - ((row_width + 1) & 1)) << 2); |
| 3505 | for (i = 0; i < row_width; i++) |
| 3506 | { |
| 3507 | value = (*sp >> shift) & 0xf; |
| 3508 | *dp = (png_byte)(value | (value << 4)); |
| 3509 | if (shift == 4) |
| 3510 | { |
| 3511 | shift = 0; |
| 3512 | sp--; |
| 3513 | } |
| 3514 | else |
| 3515 | shift = 4; |
| 3516 | |
| 3517 | dp--; |
| 3518 | } |
| 3519 | break; |
| 3520 | } |
| 3521 | } |
| 3522 | row_info->bit_depth = 8; |
| 3523 | row_info->pixel_depth = 8; |
| 3524 | row_info->rowbytes = row_width; |
| 3525 | } |
| 3526 | |
| 3527 | if (trans_value != NULL) |
| 3528 | { |
| 3529 | if (row_info->bit_depth == 8) |
| 3530 | { |
| 3531 | sp = row + (png_size_t)row_width - 1; |
| 3532 | dp = row + (png_size_t)(row_width << 1) - 1; |
| 3533 | for (i = 0; i < row_width; i++) |
| 3534 | { |
| 3535 | if (*sp == gray) |
| 3536 | *dp-- = 0; |
| 3537 | else |
| 3538 | *dp-- = 0xff; |
| 3539 | *dp-- = *sp--; |
| 3540 | } |
| 3541 | } |
| 3542 | else if (row_info->bit_depth == 16) |
| 3543 | { |
| 3544 | sp = row + row_info->rowbytes - 1; |
| 3545 | dp = row + (row_info->rowbytes << 1) - 1; |
| 3546 | for (i = 0; i < row_width; i++) |
| 3547 | { |
| 3548 | if (((png_uint_16)*(sp) | |
| 3549 | ((png_uint_16)*(sp - 1) << 8)) == gray) |
| 3550 | { |
| 3551 | *dp-- = 0; |
| 3552 | *dp-- = 0; |
| 3553 | } |
| 3554 | else |
| 3555 | { |
| 3556 | *dp-- = 0xff; |
| 3557 | *dp-- = 0xff; |
| 3558 | } |
| 3559 | *dp-- = *sp--; |
| 3560 | *dp-- = *sp--; |
| 3561 | } |
| 3562 | } |
| 3563 | row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
| 3564 | row_info->channels = 2; |
| 3565 | row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); |
| 3566 | row_info->rowbytes = |
| 3567 | ((row_width * row_info->pixel_depth) >> 3); |
| 3568 | } |
| 3569 | } |
| 3570 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value) |
| 3571 | { |
| 3572 | if (row_info->bit_depth == 8) |
| 3573 | { |
| 3574 | sp = row + (png_size_t)row_info->rowbytes - 1; |
| 3575 | dp = row + (png_size_t)(row_width << 2) - 1; |
| 3576 | for (i = 0; i < row_width; i++) |
| 3577 | { |
| 3578 | if (*(sp - 2) == trans_value->red && |
| 3579 | *(sp - 1) == trans_value->green && |
| 3580 | *(sp - 0) == trans_value->blue) |
| 3581 | *dp-- = 0; |
| 3582 | else |
| 3583 | *dp-- = 0xff; |
| 3584 | *dp-- = *sp--; |
| 3585 | *dp-- = *sp--; |
| 3586 | *dp-- = *sp--; |
| 3587 | } |
| 3588 | } |
| 3589 | else if (row_info->bit_depth == 16) |
| 3590 | { |
| 3591 | sp = row + row_info->rowbytes - 1; |
| 3592 | dp = row + (png_size_t)(row_width << 3) - 1; |
| 3593 | for (i = 0; i < row_width; i++) |
| 3594 | { |
| 3595 | if ((((png_uint_16)*(sp - 4) | |
| 3596 | ((png_uint_16)*(sp - 5) << 8)) == trans_value->red) && |
| 3597 | (((png_uint_16)*(sp - 2) | |
| 3598 | ((png_uint_16)*(sp - 3) << 8)) == trans_value->green) && |
| 3599 | (((png_uint_16)*(sp - 0) | |
| 3600 | ((png_uint_16)*(sp - 1) << 8)) == trans_value->blue)) |
| 3601 | { |
| 3602 | *dp-- = 0; |
| 3603 | *dp-- = 0; |
| 3604 | } |
| 3605 | else |
| 3606 | { |
| 3607 | *dp-- = 0xff; |
| 3608 | *dp-- = 0xff; |
| 3609 | } |
| 3610 | *dp-- = *sp--; |
| 3611 | *dp-- = *sp--; |
| 3612 | *dp-- = *sp--; |
| 3613 | *dp-- = *sp--; |
| 3614 | *dp-- = *sp--; |
| 3615 | *dp-- = *sp--; |
| 3616 | } |
| 3617 | } |
| 3618 | row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
| 3619 | row_info->channels = 4; |
| 3620 | row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); |
| 3621 | row_info->rowbytes = |
| 3622 | ((row_width * row_info->pixel_depth) >> 3); |
| 3623 | } |
| 3624 | } |
| 3625 | } |
| 3626 | #endif |
| 3627 | |
| 3628 | #if defined(PNG_READ_DITHER_SUPPORTED) |
| 3629 | void |
| 3630 | png_do_dither(png_row_infop row_info, png_bytep row, |
| 3631 | png_bytep palette_lookup, png_bytep dither_lookup) |
| 3632 | { |
| 3633 | png_bytep sp, dp; |
| 3634 | png_uint_32 i; |
| 3635 | png_uint_32 row_width=row_info->width; |
| 3636 | |
| 3637 | png_debug(1, "in png_do_dither\n"); |
| 3638 | #if defined(PNG_USELESS_TESTS_SUPPORTED) |
| 3639 | if (row != NULL && row_info != NULL) |
| 3640 | #endif |
| 3641 | { |
| 3642 | if (row_info->color_type == PNG_COLOR_TYPE_RGB && |
| 3643 | palette_lookup && row_info->bit_depth == 8) |
| 3644 | { |
| 3645 | int r, g, b, p; |
| 3646 | sp = row; |
| 3647 | dp = row; |
| 3648 | for (i = 0; i < row_width; i++) |
| 3649 | { |
| 3650 | r = *sp++; |
| 3651 | g = *sp++; |
| 3652 | b = *sp++; |
| 3653 | |
| 3654 | /* this looks real messy, but the compiler will reduce |
| 3655 | it down to a reasonable formula. For example, with |
| 3656 | 5 bits per color, we get: |
| 3657 | p = (((r >> 3) & 0x1f) << 10) | |
| 3658 | (((g >> 3) & 0x1f) << 5) | |
| 3659 | ((b >> 3) & 0x1f); |
| 3660 | */ |
| 3661 | p = (((r >> (8 - PNG_DITHER_RED_BITS)) & |
| 3662 | ((1 << PNG_DITHER_RED_BITS) - 1)) << |
| 3663 | (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | |
| 3664 | (((g >> (8 - PNG_DITHER_GREEN_BITS)) & |
| 3665 | ((1 << PNG_DITHER_GREEN_BITS) - 1)) << |
| 3666 | (PNG_DITHER_BLUE_BITS)) | |
| 3667 | ((b >> (8 - PNG_DITHER_BLUE_BITS)) & |
| 3668 | ((1 << PNG_DITHER_BLUE_BITS) - 1)); |
| 3669 | |
| 3670 | *dp++ = palette_lookup[p]; |
| 3671 | } |
| 3672 | row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
| 3673 | row_info->channels = 1; |
| 3674 | row_info->pixel_depth = row_info->bit_depth; |
| 3675 | row_info->rowbytes = |
| 3676 | ((row_width * row_info->pixel_depth + 7) >> 3); |
| 3677 | } |
| 3678 | else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && |
| 3679 | palette_lookup != NULL && row_info->bit_depth == 8) |
| 3680 | { |
| 3681 | int r, g, b, p; |
| 3682 | sp = row; |
| 3683 | dp = row; |
| 3684 | for (i = 0; i < row_width; i++) |
| 3685 | { |
| 3686 | r = *sp++; |
| 3687 | g = *sp++; |
| 3688 | b = *sp++; |
| 3689 | sp++; |
| 3690 | |
| 3691 | p = (((r >> (8 - PNG_DITHER_RED_BITS)) & |
| 3692 | ((1 << PNG_DITHER_RED_BITS) - 1)) << |
| 3693 | (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | |
| 3694 | (((g >> (8 - PNG_DITHER_GREEN_BITS)) & |
| 3695 | ((1 << PNG_DITHER_GREEN_BITS) - 1)) << |
| 3696 | (PNG_DITHER_BLUE_BITS)) | |
| 3697 | ((b >> (8 - PNG_DITHER_BLUE_BITS)) & |
| 3698 | ((1 << PNG_DITHER_BLUE_BITS) - 1)); |
| 3699 | |
| 3700 | *dp++ = palette_lookup[p]; |
| 3701 | } |
| 3702 | row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
| 3703 | row_info->channels = 1; |
| 3704 | row_info->pixel_depth = row_info->bit_depth; |
| 3705 | row_info->rowbytes = |
| 3706 | ((row_width * row_info->pixel_depth + 7) >> 3); |
| 3707 | } |
| 3708 | else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && |
| 3709 | dither_lookup && row_info->bit_depth == 8) |
| 3710 | { |
| 3711 | sp = row; |
| 3712 | for (i = 0; i < row_width; i++, sp++) |
| 3713 | { |
| 3714 | *sp = dither_lookup[*sp]; |
| 3715 | } |
| 3716 | } |
| 3717 | } |
| 3718 | } |
| 3719 | #endif |
| 3720 | |
| 3721 | #if defined(PNG_READ_GAMMA_SUPPORTED) |
| 3722 | static int png_gamma_shift[] = |
| 3723 | {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0}; |
| 3724 | |
| 3725 | /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit |
| 3726 | * tables, we don't make a full table if we are reducing to 8-bit in |
| 3727 | * the future. Note also how the gamma_16 tables are segmented so that |
| 3728 | * we don't need to allocate > 64K chunks for a full 16-bit table. |
| 3729 | */ |
| 3730 | void |
| 3731 | png_build_gamma_table(png_structp png_ptr) |
| 3732 | { |
| 3733 | png_debug(1, "in png_build_gamma_table\n"); |
| 3734 | if(png_ptr->gamma != 0.0) |
| 3735 | { |
| 3736 | if (png_ptr->bit_depth <= 8) |
| 3737 | { |
| 3738 | int i; |
| 3739 | double g; |
| 3740 | |
| 3741 | if (png_ptr->screen_gamma > .000001) |
| 3742 | g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
| 3743 | else |
| 3744 | g = 1.0; |
| 3745 | |
| 3746 | png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr, |
| 3747 | (png_uint_32)256); |
| 3748 | |
| 3749 | for (i = 0; i < 256; i++) |
| 3750 | { |
| 3751 | png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0, |
| 3752 | g) * 255.0 + .5); |
| 3753 | } |
| 3754 | |
| 3755 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ |
| 3756 | defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
| 3757 | if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY)) |
| 3758 | { |
| 3759 | |
| 3760 | g = 1.0 / (png_ptr->gamma); |
| 3761 | |
| 3762 | png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr, |
| 3763 | (png_uint_32)256); |
| 3764 | |
| 3765 | for (i = 0; i < 256; i++) |
| 3766 | { |
| 3767 | png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0, |
| 3768 | g) * 255.0 + .5); |
| 3769 | } |
| 3770 | |
| 3771 | |
| 3772 | png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr, |
| 3773 | (png_uint_32)256); |
| 3774 | |
| 3775 | if(png_ptr->screen_gamma > 0.000001) |
| 3776 | g = 1.0 / png_ptr->screen_gamma; |
| 3777 | else |
| 3778 | g = png_ptr->gamma; /* probably doing rgb_to_gray */ |
| 3779 | |
| 3780 | for (i = 0; i < 256; i++) |
| 3781 | { |
| 3782 | png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0, |
| 3783 | g) * 255.0 + .5); |
| 3784 | |
| 3785 | } |
| 3786 | } |
| 3787 | #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ |
| 3788 | } |
| 3789 | else |
| 3790 | { |
| 3791 | double g; |
| 3792 | int i, j, shift, num; |
| 3793 | int sig_bit; |
| 3794 | png_uint_32 ig; |
| 3795 | |
| 3796 | if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) |
| 3797 | { |
| 3798 | sig_bit = (int)png_ptr->sig_bit.red; |
| 3799 | if ((int)png_ptr->sig_bit.green > sig_bit) |
| 3800 | sig_bit = png_ptr->sig_bit.green; |
| 3801 | if ((int)png_ptr->sig_bit.blue > sig_bit) |
| 3802 | sig_bit = png_ptr->sig_bit.blue; |
| 3803 | } |
| 3804 | else |
| 3805 | { |
| 3806 | sig_bit = (int)png_ptr->sig_bit.gray; |
| 3807 | } |
| 3808 | |
| 3809 | if (sig_bit > 0) |
| 3810 | shift = 16 - sig_bit; |
| 3811 | else |
| 3812 | shift = 0; |
| 3813 | |
| 3814 | if (png_ptr->transformations & PNG_16_TO_8) |
| 3815 | { |
| 3816 | if (shift < (16 - PNG_MAX_GAMMA_8)) |
| 3817 | shift = (16 - PNG_MAX_GAMMA_8); |
| 3818 | } |
| 3819 | |
| 3820 | if (shift > 8) |
| 3821 | shift = 8; |
| 3822 | if (shift < 0) |
| 3823 | shift = 0; |
| 3824 | |
| 3825 | png_ptr->gamma_shift = (png_byte)shift; |
| 3826 | |
| 3827 | num = (1 << (8 - shift)); |
| 3828 | |
| 3829 | if (png_ptr->screen_gamma > .000001) |
| 3830 | g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
| 3831 | else |
| 3832 | g = 1.0; |
| 3833 | |
| 3834 | png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr, |
| 3835 | (png_uint_32)(num * sizeof (png_uint_16p))); |
| 3836 | |
| 3837 | if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND)) |
| 3838 | { |
| 3839 | double fin, fout; |
| 3840 | png_uint_32 last, max; |
| 3841 | |
| 3842 | for (i = 0; i < num; i++) |
| 3843 | { |
| 3844 | png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, |
| 3845 | (png_uint_32)(256 * sizeof (png_uint_16))); |
| 3846 | } |
| 3847 | |
| 3848 | g = 1.0 / g; |
| 3849 | last = 0; |
| 3850 | for (i = 0; i < 256; i++) |
| 3851 | { |
| 3852 | fout = ((double)i + 0.5) / 256.0; |
| 3853 | fin = pow(fout, g); |
| 3854 | max = (png_uint_32)(fin * (double)((png_uint_32)num << 8)); |
| 3855 | while (last <= max) |
| 3856 | { |
| 3857 | png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] |
| 3858 | [(int)(last >> (8 - shift))] = (png_uint_16)( |
| 3859 | (png_uint_16)i | ((png_uint_16)i << 8)); |
| 3860 | last++; |
| 3861 | } |
| 3862 | } |
| 3863 | while (last < ((png_uint_32)num << 8)) |
| 3864 | { |
| 3865 | png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] |
| 3866 | [(int)(last >> (8 - shift))] = (png_uint_16)65535L; |
| 3867 | last++; |
| 3868 | } |
| 3869 | } |
| 3870 | else |
| 3871 | { |
| 3872 | for (i = 0; i < num; i++) |
| 3873 | { |
| 3874 | png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, |
| 3875 | (png_uint_32)(256 * sizeof (png_uint_16))); |
| 3876 | |
| 3877 | ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4); |
| 3878 | for (j = 0; j < 256; j++) |
| 3879 | { |
| 3880 | png_ptr->gamma_16_table[i][j] = |
| 3881 | (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
| 3882 | 65535.0, g) * 65535.0 + .5); |
| 3883 | } |
| 3884 | } |
| 3885 | } |
| 3886 | |
| 3887 | #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ |
| 3888 | defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
| 3889 | if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY)) |
| 3890 | { |
| 3891 | |
| 3892 | g = 1.0 / (png_ptr->gamma); |
| 3893 | |
| 3894 | png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr, |
| 3895 | (png_uint_32)(num * sizeof (png_uint_16p ))); |
| 3896 | |
| 3897 | for (i = 0; i < num; i++) |
| 3898 | { |
| 3899 | png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr, |
| 3900 | (png_uint_32)(256 * sizeof (png_uint_16))); |
| 3901 | |
| 3902 | ig = (((png_uint_32)i * |
| 3903 | (png_uint_32)png_gamma_shift[shift]) >> 4); |
| 3904 | for (j = 0; j < 256; j++) |
| 3905 | { |
| 3906 | png_ptr->gamma_16_to_1[i][j] = |
| 3907 | (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
| 3908 | 65535.0, g) * 65535.0 + .5); |
| 3909 | } |
| 3910 | } |
| 3911 | |
| 3912 | if(png_ptr->screen_gamma > 0.000001) |
| 3913 | g = 1.0 / png_ptr->screen_gamma; |
| 3914 | else |
| 3915 | g = png_ptr->gamma; /* probably doing rgb_to_gray */ |
| 3916 | |
| 3917 | png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr, |
| 3918 | (png_uint_32)(num * sizeof (png_uint_16p))); |
| 3919 | |
| 3920 | for (i = 0; i < num; i++) |
| 3921 | { |
| 3922 | png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr, |
| 3923 | (png_uint_32)(256 * sizeof (png_uint_16))); |
| 3924 | |
| 3925 | ig = (((png_uint_32)i * |
| 3926 | (png_uint_32)png_gamma_shift[shift]) >> 4); |
| 3927 | for (j = 0; j < 256; j++) |
| 3928 | { |
| 3929 | png_ptr->gamma_16_from_1[i][j] = |
| 3930 | (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
| 3931 | 65535.0, g) * 65535.0 + .5); |
| 3932 | } |
| 3933 | } |
| 3934 | } |
| 3935 | #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ |
| 3936 | } |
| 3937 | } |
| 3938 | } |
| 3939 | #endif |
| 3940 | |