diff options
Diffstat (limited to 'src/3rdparty/libpng/pngrtran.c')
| -rw-r--r-- | src/3rdparty/libpng/pngrtran.c | 828 |
1 files changed, 452 insertions, 376 deletions
diff --git a/src/3rdparty/libpng/pngrtran.c b/src/3rdparty/libpng/pngrtran.c index d5b9d45..5561852 100644 --- a/src/3rdparty/libpng/pngrtran.c +++ b/src/3rdparty/libpng/pngrtran.c @@ -1,8 +1,8 @@ /* pngrtran.c - transforms the data in a row for PNG readers * - * Last changed in libpng 1.5.4 [July 7, 2011] - * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * Last changed in libpng 1.5.10 [March 8, 2012] + * Copyright (c) 1998-2012 Glenn Randers-Pehrson * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * @@ -18,8 +18,6 @@ #include "pngpriv.h" -namespace PrivatePng { - #ifdef PNG_READ_SUPPORTED /* Set the action on getting a CRC error for an ancillary or critical chunk. */ @@ -938,15 +936,15 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, switch(error_action) { - case 1: + case PNG_ERROR_ACTION_NONE: png_ptr->transformations |= PNG_RGB_TO_GRAY; break; - case 2: + case PNG_ERROR_ACTION_WARN: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; break; - case 3: + case PNG_ERROR_ACTION_ERROR: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; break; @@ -970,13 +968,17 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, { png_uint_16 red_int, green_int; - red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); - green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); + /* NOTE: this calculation does not round, but this behavior is retained + * for consistency, the inaccuracy is very small. The code here always + * overwrites the coefficients, regardless of whether they have been + * defaulted or set already. + */ + red_int = (png_uint_16)(((png_uint_32)red*32768)/100000); + green_int = (png_uint_16)(((png_uint_32)green*32768)/100000); png_ptr->rgb_to_gray_red_coeff = red_int; png_ptr->rgb_to_gray_green_coeff = green_int; - png_ptr->rgb_to_gray_blue_coeff = - (png_uint_16)(32768 - red_int - green_int); + png_ptr->rgb_to_gray_coefficients_set = 1; } else @@ -985,17 +987,18 @@ png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); - /* Use the defaults, from the cHRM chunk if set, else the built in Rec - * 709 values (which correspond to sRGB, so we don't have to worry - * about the sRGB chunk!) + /* Use the defaults, from the cHRM chunk if set, else the historical + * values which are close to the sRGB/HDTV/ITU-Rec 709 values. See + * png_do_rgb_to_gray for more discussion of the values. In this case + * the coefficients are not marked as 'set' and are not overwritten if + * something has already provided a default. */ if (png_ptr->rgb_to_gray_red_coeff == 0 && - png_ptr->rgb_to_gray_green_coeff == 0 && - png_ptr->rgb_to_gray_blue_coeff == 0) + png_ptr->rgb_to_gray_green_coeff == 0) { - png_ptr->rgb_to_gray_red_coeff = 6968; /* .212671 * 32768 + .5 */ - png_ptr->rgb_to_gray_green_coeff = 23434; /* .715160 * 32768 + .5 */ - png_ptr->rgb_to_gray_blue_coeff = 2366; + png_ptr->rgb_to_gray_red_coeff = 6968; + png_ptr->rgb_to_gray_green_coeff = 23434; + /* png_ptr->rgb_to_gray_blue_coeff = 2366; */ } } } @@ -1195,53 +1198,44 @@ png_init_rgb_transformations(png_structp png_ptr) { { /* Expand background and tRNS chunks */ + int gray = png_ptr->background.gray; + int trans_gray = png_ptr->trans_color.gray; + switch (png_ptr->bit_depth) { case 1: - png_ptr->background.gray *= (png_uint_16)0xff; - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) - { - png_ptr->trans_color.gray *= (png_uint_16)0xff; - png_ptr->trans_color.red = png_ptr->trans_color.green - = png_ptr->trans_color.blue = png_ptr->trans_color.gray; - } + gray *= 0xff; + trans_gray *= 0xff; break; case 2: - png_ptr->background.gray *= (png_uint_16)0x55; - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) - { - png_ptr->trans_color.gray *= (png_uint_16)0x55; - png_ptr->trans_color.red = png_ptr->trans_color.green - = png_ptr->trans_color.blue = png_ptr->trans_color.gray; - } + gray *= 0x55; + trans_gray *= 0x55; break; case 4: - png_ptr->background.gray *= (png_uint_16)0x11; - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; - if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) - { - png_ptr->trans_color.gray *= (png_uint_16)0x11; - png_ptr->trans_color.red = png_ptr->trans_color.green - = png_ptr->trans_color.blue = png_ptr->trans_color.gray; - } + gray *= 0x11; + trans_gray *= 0x11; break; default: case 8: + /* Already 8 bits, fall through */ case 16: - png_ptr->background.red = png_ptr->background.green - = png_ptr->background.blue = png_ptr->background.gray; + /* Already a full 16 bits */ break; } + + png_ptr->background.red = png_ptr->background.green = + png_ptr->background.blue = (png_uint_16)gray; + + if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) + { + png_ptr->trans_color.red = png_ptr->trans_color.green = + png_ptr->trans_color.blue = (png_uint_16)trans_gray; + } } } /* background expand and (therefore) no alpha association. */ #endif /* PNG_READ_EXPAND_SUPPORTED && PNG_READ_BACKGROUND_SUPPORTED */ @@ -1403,7 +1397,7 @@ png_init_read_transformations(png_structp png_ptr) if (png_ptr->transformations & PNG_BACKGROUND_EXPAND) { /* PNG_BACKGROUND_EXPAND: the background is in the file color space, so if - * the file was greyscale the background value is gray. + * the file was grayscale the background value is gray. */ if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; @@ -1471,6 +1465,28 @@ png_init_read_transformations(png_structp png_ptr) } #endif /* PNG_READ_BACKGROUND_SUPPORTED && PNG_READ_EXPAND_16_SUPPORTED */ +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ + (defined(PNG_READ_SCALE_16_TO_8_SUPPORTED) || \ + defined(PNG_READ_STRIP_16_TO_8_SUPPORTED)) + if ((png_ptr->transformations & (PNG_16_TO_8|PNG_SCALE_16_TO_8)) && + (png_ptr->transformations & PNG_COMPOSE) && + !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && + png_ptr->bit_depth == 16) + { + /* On the other hand, if a 16-bit file is to be reduced to 8-bits per + * component this will also happen after PNG_COMPOSE and so the background + * color must be pre-expanded here. + * + * TODO: fix this too. + */ + png_ptr->background.red = (png_uint_16)(png_ptr->background.red * 257); + png_ptr->background.green = + (png_uint_16)(png_ptr->background.green * 257); + png_ptr->background.blue = (png_uint_16)(png_ptr->background.blue * 257); + png_ptr->background.gray = (png_uint_16)(png_ptr->background.gray * 257); + } +#endif + /* NOTE: below 'PNG_READ_ALPHA_MODE_SUPPORTED' is presumed to also enable the * background support (see the comments in scripts/pnglibconf.dfa), this * allows pre-multiplication of the alpha channel to be implemented as @@ -1518,6 +1534,16 @@ png_init_read_transformations(png_structp png_ptr) #ifdef PNG_READ_BACKGROUND_SUPPORTED if (png_ptr->transformations & PNG_COMPOSE) { + /* Issue a warning about this combination: because RGB_TO_GRAY is + * optimized to do the gamma transform if present yet do_background has + * to do the same thing if both options are set a + * double-gamma-correction happens. This is true in all versions of + * libpng to date. + */ + if (png_ptr->transformations & PNG_RGB_TO_GRAY) + png_warning(png_ptr, + "libpng does not support gamma+background+rgb_to_gray"); + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { /* We don't get to here unless there is a tRNS chunk with non-opaque @@ -1637,7 +1663,7 @@ png_init_read_transformations(png_structp png_ptr) /* Prevent the transformations being done again. * - * NOTE: this is highly dubious; it zaps the transformations in + * NOTE: this is highly dubious; it removes the transformations in * place. This seems inconsistent with the general treatment of the * transformations elsewhere. */ @@ -1647,8 +1673,9 @@ png_init_read_transformations(png_structp png_ptr) /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ else /* color_type != PNG_COLOR_TYPE_PALETTE */ { - png_fixed_point g = PNG_FP_1; - png_fixed_point gs = PNG_FP_1; + int gs_sig, g_sig; + png_fixed_point g = PNG_FP_1; /* Correction to linear */ + png_fixed_point gs = PNG_FP_1; /* Correction to screen */ switch (png_ptr->background_gamma_type) { @@ -1672,34 +1699,45 @@ png_init_read_transformations(png_structp png_ptr) png_error(png_ptr, "invalid background gamma type"); } - png_ptr->background_1.gray = png_gamma_correct(png_ptr, - png_ptr->background.gray, g); + g_sig = png_gamma_significant(g); + gs_sig = png_gamma_significant(gs); + + if (g_sig) + png_ptr->background_1.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, g); - png_ptr->background.gray = png_gamma_correct(png_ptr, - png_ptr->background.gray, gs); + if (gs_sig) + png_ptr->background.gray = png_gamma_correct(png_ptr, + png_ptr->background.gray, gs); if ((png_ptr->background.red != png_ptr->background.green) || (png_ptr->background.red != png_ptr->background.blue) || (png_ptr->background.red != png_ptr->background.gray)) { /* RGB or RGBA with color background */ - png_ptr->background_1.red = png_gamma_correct(png_ptr, - png_ptr->background.red, g); + if (g_sig) + { + png_ptr->background_1.red = png_gamma_correct(png_ptr, + png_ptr->background.red, g); - png_ptr->background_1.green = png_gamma_correct(png_ptr, - png_ptr->background.green, g); + png_ptr->background_1.green = png_gamma_correct(png_ptr, + png_ptr->background.green, g); - png_ptr->background_1.blue = png_gamma_correct(png_ptr, - png_ptr->background.blue, g); + png_ptr->background_1.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, g); + } - png_ptr->background.red = png_gamma_correct(png_ptr, - png_ptr->background.red, gs); + if (gs_sig) + { + png_ptr->background.red = png_gamma_correct(png_ptr, + png_ptr->background.red, gs); - png_ptr->background.green = png_gamma_correct(png_ptr, - png_ptr->background.green, gs); + png_ptr->background.green = png_gamma_correct(png_ptr, + png_ptr->background.green, gs); - png_ptr->background.blue = png_gamma_correct(png_ptr, - png_ptr->background.blue, gs); + png_ptr->background.blue = png_gamma_correct(png_ptr, + png_ptr->background.blue, gs); + } } else @@ -1711,13 +1749,22 @@ png_init_read_transformations(png_structp png_ptr) png_ptr->background.red = png_ptr->background.green = png_ptr->background.blue = png_ptr->background.gray; } + + /* The background is now in screen gamma: */ + png_ptr->background_gamma_type = PNG_BACKGROUND_GAMMA_SCREEN; } /* color_type != PNG_COLOR_TYPE_PALETTE */ }/* png_ptr->transformations & PNG_BACKGROUND */ else /* Transformation does not include PNG_BACKGROUND */ #endif /* PNG_READ_BACKGROUND_SUPPORTED */ - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* RGB_TO_GRAY needs to have non-gamma-corrected values! */ + && ((png_ptr->transformations & PNG_EXPAND) == 0 || + (png_ptr->transformations & PNG_RGB_TO_GRAY) == 0) +#endif + ) { png_colorp palette = png_ptr->palette; int num_palette = png_ptr->num_palette; @@ -1783,28 +1830,43 @@ png_init_read_transformations(png_structp png_ptr) #ifdef PNG_READ_SHIFT_SUPPORTED if ((png_ptr->transformations & PNG_SHIFT) && + !(png_ptr->transformations & PNG_EXPAND) && (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) { - png_uint_16 i; - png_uint_16 istop = png_ptr->num_palette; - int sr = 8 - png_ptr->sig_bit.red; - int sg = 8 - png_ptr->sig_bit.green; - int sb = 8 - png_ptr->sig_bit.blue; + int i; + int istop = png_ptr->num_palette; + int shift = 8 - png_ptr->sig_bit.red; + + png_ptr->transformations &= ~PNG_SHIFT; + + /* significant bits can be in the range 1 to 7 for a meaninful result, if + * the number of significant bits is 0 then no shift is done (this is an + * error condition which is silently ignored.) + */ + if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].red; - if (sr < 0 || sr > 8) - sr = 0; + component >>= shift; + png_ptr->palette[i].red = (png_byte)component; + } - if (sg < 0 || sg > 8) - sg = 0; + shift = 8 - png_ptr->sig_bit.green; + if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) + { + int component = png_ptr->palette[i].green; - if (sb < 0 || sb > 8) - sb = 0; + component >>= shift; + png_ptr->palette[i].green = (png_byte)component; + } - for (i = 0; i < istop; i++) + shift = 8 - png_ptr->sig_bit.blue; + if (shift > 0 && shift < 8) for (i=0; i<istop; ++i) { - png_ptr->palette[i].red >>= sr; - png_ptr->palette[i].green >>= sg; - png_ptr->palette[i].blue >>= sb; + int component = png_ptr->palette[i].blue; + + component >>= shift; + png_ptr->palette[i].blue = (png_byte)component; } } #endif /* PNG_READ_SHIFT_SUPPORTED */ @@ -1897,7 +1959,7 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) info_ptr->bit_depth = 8; # else -# if PNG_READ_SCALE_16_TO_8_SUPPORTED +# ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED png_ptr->transformations |= PNG_SCALE_16_TO_8; info_ptr->bit_depth = 8; # else @@ -1910,12 +1972,14 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED if (png_ptr->transformations & PNG_GRAY_TO_RGB) - info_ptr->color_type |= PNG_COLOR_MASK_COLOR; + info_ptr->color_type = (png_byte)(info_ptr->color_type | + PNG_COLOR_MASK_COLOR); #endif #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED if (png_ptr->transformations & PNG_RGB_TO_GRAY) - info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_COLOR); #endif #ifdef PNG_READ_QUANTIZE_SUPPORTED @@ -1955,7 +2019,8 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr) #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED if (png_ptr->transformations & PNG_STRIP_ALPHA) { - info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; + info_ptr->color_type = (png_byte)(info_ptr->color_type & + ~PNG_COLOR_MASK_ALPHA); info_ptr->num_trans = 0; } #endif @@ -2012,7 +2077,7 @@ defined(PNG_READ_USER_TRANSFORM_SUPPORTED) * decide how it fits in with the other transformations here. */ void /* PRIVATE */ -png_do_read_transformations(png_structp png_ptr) +png_do_read_transformations(png_structp png_ptr, png_row_infop row_info) { png_debug(1, "in png_do_read_transformations"); @@ -2043,9 +2108,9 @@ png_do_read_transformations(png_structp png_ptr) #ifdef PNG_READ_EXPAND_SUPPORTED if (png_ptr->transformations & PNG_EXPAND) { - if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) { - png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_expand_palette(row_info, png_ptr->row_buf + 1, png_ptr->palette, png_ptr->trans_alpha, png_ptr->num_trans); } @@ -2053,11 +2118,11 @@ png_do_read_transformations(png_structp png_ptr) { if (png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND_tRNS)) - png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_expand(row_info, png_ptr->row_buf + 1, &(png_ptr->trans_color)); else - png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_expand(row_info, png_ptr->row_buf + 1, NULL); } } @@ -2066,9 +2131,9 @@ png_do_read_transformations(png_structp png_ptr) #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED if ((png_ptr->transformations & PNG_STRIP_ALPHA) && !(png_ptr->transformations & PNG_COMPOSE) && - (png_ptr->row_info.color_type == PNG_COLOR_TYPE_RGB_ALPHA || - png_ptr->row_info.color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) - png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1, + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, 0 /* at_start == false, because SWAP_ALPHA happens later */); #endif @@ -2076,7 +2141,7 @@ png_do_read_transformations(png_structp png_ptr) if (png_ptr->transformations & PNG_RGB_TO_GRAY) { int rgb_error = - png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), + png_do_rgb_to_gray(png_ptr, row_info, png_ptr->row_buf + 1); if (rgb_error) @@ -2130,45 +2195,55 @@ png_do_read_transformations(png_structp png_ptr) */ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) - png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); #endif #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ (defined PNG_READ_ALPHA_MODE_SUPPORTED) if (png_ptr->transformations & PNG_COMPOSE) - png_do_compose(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr); + png_do_compose(row_info, png_ptr->row_buf + 1, png_ptr); #endif #ifdef PNG_READ_GAMMA_SUPPORTED if ((png_ptr->transformations & PNG_GAMMA) && +#ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED + /* Because RGB_TO_GRAY does the gamma transform. */ + !(png_ptr->transformations & PNG_RGB_TO_GRAY) && +#endif #if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ (defined PNG_READ_ALPHA_MODE_SUPPORTED) + /* Because PNG_COMPOSE does the gamma transform if there is something to + * do (if there is an alpha channel or transparency.) + */ !((png_ptr->transformations & PNG_COMPOSE) && ((png_ptr->num_trans != 0) || (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && #endif + /* Because png_init_read_transformations transforms the palette, unless + * RGB_TO_GRAY will do the transform. + */ (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) - png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr); + png_do_gamma(row_info, png_ptr->row_buf + 1, png_ptr); #endif #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED if ((png_ptr->transformations & PNG_STRIP_ALPHA) && (png_ptr->transformations & PNG_COMPOSE) && - (png_ptr->row_info.color_type == PNG_COLOR_TYPE_RGB_ALPHA || - png_ptr->row_info.color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) - png_do_strip_channel(&(png_ptr->row_info), png_ptr->row_buf + 1, + (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)) + png_do_strip_channel(row_info, png_ptr->row_buf + 1, 0 /* at_start == false, because SWAP_ALPHA happens later */); #endif #ifdef PNG_READ_ALPHA_MODE_SUPPORTED if ((png_ptr->transformations & PNG_ENCODE_ALPHA) && - (png_ptr->row_info.color_type & PNG_COLOR_MASK_ALPHA)) - png_do_encode_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1, png_ptr); + (row_info->color_type & PNG_COLOR_MASK_ALPHA)) + png_do_encode_alpha(row_info, png_ptr->row_buf + 1, png_ptr); #endif #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED if (png_ptr->transformations & PNG_SCALE_16_TO_8) - png_do_scale_16_to_8(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_scale_16_to_8(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED @@ -2177,16 +2252,16 @@ png_do_read_transformations(png_structp png_ptr) * calling the API or in a TRANSFORM flag) this is what happens. */ if (png_ptr->transformations & PNG_16_TO_8) - png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_chop(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_QUANTIZE_SUPPORTED if (png_ptr->transformations & PNG_QUANTIZE) { - png_do_quantize(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_quantize(row_info, png_ptr->row_buf + 1, png_ptr->palette_lookup, png_ptr->quantize_index); - if (png_ptr->row_info.rowbytes == 0) + if (row_info->rowbytes == 0) png_error(png_ptr, "png_do_quantize returned rowbytes=0"); } #endif /* PNG_READ_QUANTIZE_SUPPORTED */ @@ -2198,62 +2273,68 @@ png_do_read_transformations(png_structp png_ptr) * better accuracy results faster!) */ if (png_ptr->transformations & PNG_EXPAND_16) - png_do_expand_16(&png_ptr->row_info, png_ptr->row_buf + 1); + png_do_expand_16(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED /*NOTE: moved here in 1.5.4 (from much later in this list.) */ if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) - png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_gray_to_rgb(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_INVERT_SUPPORTED if (png_ptr->transformations & PNG_INVERT_MONO) - png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_invert(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_SHIFT_SUPPORTED if (png_ptr->transformations & PNG_SHIFT) - png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_unshift(row_info, png_ptr->row_buf + 1, &(png_ptr->shift)); #endif #ifdef PNG_READ_PACK_SUPPORTED if (png_ptr->transformations & PNG_PACK) - png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_unpack(row_info, png_ptr->row_buf + 1); +#endif + +#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED + /* Added at libpng-1.5.10 */ + if (row_info->color_type == PNG_COLOR_TYPE_PALETTE) + png_do_check_palette_indexes(png_ptr, row_info); #endif #ifdef PNG_READ_BGR_SUPPORTED if (png_ptr->transformations & PNG_BGR) - png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_bgr(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_PACKSWAP_SUPPORTED if (png_ptr->transformations & PNG_PACKSWAP) - png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_packswap(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_FILLER_SUPPORTED if (png_ptr->transformations & PNG_FILLER) - png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_do_read_filler(row_info, png_ptr->row_buf + 1, (png_uint_32)png_ptr->filler, png_ptr->flags); #endif #ifdef PNG_READ_INVERT_ALPHA_SUPPORTED if (png_ptr->transformations & PNG_INVERT_ALPHA) - png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_read_invert_alpha(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_SWAP_ALPHA_SUPPORTED if (png_ptr->transformations & PNG_SWAP_ALPHA) - png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_read_swap_alpha(row_info, png_ptr->row_buf + 1); #endif #ifdef PNG_READ_16BIT_SUPPORTED #ifdef PNG_READ_SWAP_SUPPORTED if (png_ptr->transformations & PNG_SWAP_BYTES) - png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); + png_do_swap(row_info, png_ptr->row_buf + 1); #endif #endif @@ -2262,8 +2343,8 @@ png_do_read_transformations(png_structp png_ptr) { if (png_ptr->read_user_transform_fn != NULL) (*(png_ptr->read_user_transform_fn)) /* User read transform function */ - (png_ptr, /* png_ptr */ - &(png_ptr->row_info), /* row_info: */ + (png_ptr, /* png_ptr */ + row_info, /* row_info: */ /* png_uint_32 width; width of row */ /* png_size_t rowbytes; number of bytes in row */ /* png_byte color_type; color type of pixels */ @@ -2273,16 +2354,15 @@ png_do_read_transformations(png_structp png_ptr) png_ptr->row_buf + 1); /* start of pixel data for row */ #ifdef PNG_USER_TRANSFORM_PTR_SUPPORTED if (png_ptr->user_transform_depth) - png_ptr->row_info.bit_depth = png_ptr->user_transform_depth; + row_info->bit_depth = png_ptr->user_transform_depth; if (png_ptr->user_transform_channels) - png_ptr->row_info.channels = png_ptr->user_transform_channels; + row_info->channels = png_ptr->user_transform_channels; #endif - png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * - png_ptr->row_info.channels); + row_info->pixel_depth = (png_byte)(row_info->bit_depth * + row_info->channels); - png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, - png_ptr->row_info.width); + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_info->width); } #endif } @@ -2396,105 +2476,128 @@ void /* PRIVATE */ png_do_unshift(png_row_infop row_info, png_bytep row, png_const_color_8p sig_bits) { + int color_type; + png_debug(1, "in png_do_unshift"); - if ( - row_info->color_type != PNG_COLOR_TYPE_PALETTE) + /* The palette case has already been handled in the _init routine. */ + color_type = row_info->color_type; + + if (color_type != PNG_COLOR_TYPE_PALETTE) { int shift[4]; int channels = 0; - int c; - png_uint_16 value = 0; - png_uint_32 row_width = row_info->width; + int bit_depth = row_info->bit_depth; - if (row_info->color_type & PNG_COLOR_MASK_COLOR) + if (color_type & PNG_COLOR_MASK_COLOR) { - shift[channels++] = row_info->bit_depth - sig_bits->red; - shift[channels++] = row_info->bit_depth - sig_bits->green; - shift[channels++] = row_info->bit_depth - sig_bits->blue; + shift[channels++] = bit_depth - sig_bits->red; + shift[channels++] = bit_depth - sig_bits->green; + shift[channels++] = bit_depth - sig_bits->blue; } else { - shift[channels++] = row_info->bit_depth - sig_bits->gray; + shift[channels++] = bit_depth - sig_bits->gray; } - if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + if (color_type & PNG_COLOR_MASK_ALPHA) { - shift[channels++] = row_info->bit_depth - sig_bits->alpha; + shift[channels++] = bit_depth - sig_bits->alpha; } - for (c = 0; c < channels; c++) { - if (shift[c] <= 0) - shift[c] = 0; + int c, have_shift; - else - value = 1; - } + for (c = have_shift = 0; c < channels; ++c) + { + /* A shift of more than the bit depth is an error condition but it + * gets ignored here. + */ + if (shift[c] <= 0 || shift[c] >= bit_depth) + shift[c] = 0; - if (!value) - return; + else + have_shift = 1; + } - switch (row_info->bit_depth) + if (!have_shift) + return; + } + + switch (bit_depth) { default: + /* Must be 1bpp gray: should not be here! */ + /* NOTREACHED */ break; case 2: + /* Must be 2bpp gray */ + /* assert(channels == 1 && shift[0] == 1) */ { - png_bytep bp; - png_size_t i; - png_size_t istop = row_info->rowbytes; + png_bytep bp = row; + png_bytep bp_end = bp + row_info->rowbytes; - for (bp = row, i = 0; i < istop; i++) + while (bp < bp_end) { - *bp >>= 1; - *bp++ &= 0x55; + int b = (*bp >> 1) & 0x55; + *bp++ = (png_byte)b; } break; } case 4: + /* Must be 4bpp gray */ + /* assert(channels == 1) */ { png_bytep bp = row; - png_size_t i; - png_size_t istop = row_info->rowbytes; - png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) | - (png_byte)((int)0xf >> shift[0])); + png_bytep bp_end = bp + row_info->rowbytes; + int gray_shift = shift[0]; + int mask = 0xf >> gray_shift; - for (i = 0; i < istop; i++) + mask |= mask << 4; + + while (bp < bp_end) { - *bp >>= shift[0]; - *bp++ &= mask; + int b = (*bp >> gray_shift) & mask; + *bp++ = (png_byte)b; } break; } case 8: + /* Single byte components, G, GA, RGB, RGBA */ { png_bytep bp = row; - png_uint_32 i; - png_uint_32 istop = row_width * channels; + png_bytep bp_end = bp + row_info->rowbytes; + int channel = 0; - for (i = 0; i < istop; i++) + while (bp < bp_end) { - *bp++ >>= shift[i%channels]; + int b = *bp >> shift[channel]; + if (++channel >= channels) + channel = 0; + *bp++ = (png_byte)b; } break; } #ifdef PNG_READ_16BIT_SUPPORTED case 16: + /* Double byte components, G, GA, RGB, RGBA */ { png_bytep bp = row; - png_uint_32 i; - png_uint_32 istop = channels * row_width; + png_bytep bp_end = bp + row_info->rowbytes; + int channel = 0; - for (i = 0; i < istop; i++) + while (bp < bp_end) { - value = (png_uint_16)((*bp << 8) + *(bp + 1)); - value >>= shift[i%channels]; + int value = (bp[0] << 8) + bp[1]; + + value >>= shift[channel]; + if (++channel >= channels) + channel = 0; *bp++ = (png_byte)(value >> 8); *bp++ = (png_byte)(value & 0xff); } @@ -2516,7 +2619,7 @@ png_do_scale_16_to_8(png_row_infop row_info, png_bytep row) if (row_info->bit_depth == 16) { png_bytep sp = row; /* source */ - png_bytep dp = row; /* destinaton */ + png_bytep dp = row; /* destination */ png_bytep ep = sp + row_info->rowbytes; /* end+1 */ while (sp < ep) @@ -2577,7 +2680,7 @@ png_do_chop(png_row_infop row_info, png_bytep row) if (row_info->bit_depth == 16) { png_bytep sp = row; /* source */ - png_bytep dp = row; /* destinaton */ + png_bytep dp = row; /* destination */ png_bytep ep = sp + row_info->rowbytes; /* end+1 */ while (sp < ep) @@ -3057,7 +3160,7 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) } } } - row_info->channels += (png_byte)2; + row_info->channels = (png_byte)(row_info->channels + 2); row_info->color_type |= PNG_COLOR_MASK_COLOR; row_info->pixel_depth = (png_byte)(row_info->channels * row_info->bit_depth); @@ -3068,33 +3171,61 @@ png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) #ifdef PNG_READ_RGB_TO_GRAY_SUPPORTED /* Reduce RGB files to grayscale, with or without alpha - * using the equation given in Poynton's ColorFAQ at - * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008) - * New link: - * <http://www.poynton.com/notes/colour_and_gamma/> + * using the equation given in Poynton's ColorFAQ of 1998-01-04 at + * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008 but + * versions dated 1998 through November 2002 have been archived at + * http://web.archive.org/web/20000816232553/http://www.inforamp.net/ + * ~poynton/notes/colour_and_gamma/ColorFAQ.txt ) * Charles Poynton poynton at poynton.com * * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B * - * We approximate this with + * which can be expressed with integers as + * + * Y = (6969 * R + 23434 * G + 2365 * B)/32768 + * + * Poynton's current link (as of January 2003 through July 2011): + * <http://www.poynton.com/notes/colour_and_gamma/> + * has changed the numbers slightly: * - * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B + * Y = 0.2126*R + 0.7152*G + 0.0722*B * * which can be expressed with integers as * - * Y = (6969 * R + 23434 * G + 2365 * B)/32768 + * Y = (6966 * R + 23436 * G + 2366 * B)/32768 + * + * Historically, however, libpng uses numbers derived from the ITU-R Rec 709 + * end point chromaticities and the D65 white point. Depending on the + * precision used for the D65 white point this produces a variety of different + * numbers, however if the four decimal place value used in ITU-R Rec 709 is + * used (0.3127,0.3290) the Y calculation would be: + * + * Y = (6968 * R + 23435 * G + 2366 * B)/32768 + * + * While this is correct the rounding results in an overflow for white, because + * the sum of the rounded coefficients is 32769, not 32768. Consequently + * libpng uses, instead, the closest non-overflowing approximation: + * + * Y = (6968 * R + 23434 * G + 2366 * B)/32768 + * + * Starting with libpng-1.5.5, if the image being converted has a cHRM chunk + * (including an sRGB chunk) then the chromaticities are used to calculate the + * coefficients. See the chunk handling in pngrutil.c for more information. * - * The calculation is to be done in a linear colorspace. + * In all cases the calculation is to be done in a linear colorspace. If no + * gamma information is available to correct the encoding of the original RGB + * values this results in an implicit assumption that the original PNG RGB + * values were linear. * - * Other integer coefficents can be used via png_set_rgb_to_gray(). + * Other integer coefficents can be used via png_set_rgb_to_gray(). Because + * the API takes just red and green coefficients the blue coefficient is + * calculated to make the sum 32768. This will result in different rounding + * to that used above. */ int /* PRIVATE */ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) { - png_uint_32 i; - - png_uint_32 row_width = row_info->width; int rgb_error = 0; png_debug(1, "in png_do_rgb_to_gray"); @@ -3102,235 +3233,180 @@ png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) if (!(row_info->color_type & PNG_COLOR_MASK_PALETTE) && (row_info->color_type & PNG_COLOR_MASK_COLOR)) { - png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; - png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; - png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; + PNG_CONST png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; + PNG_CONST png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; + PNG_CONST png_uint_32 bc = 32768 - rc - gc; + PNG_CONST png_uint_32 row_width = row_info->width; + PNG_CONST int have_alpha = + (row_info->color_type & PNG_COLOR_MASK_ALPHA) != 0; - if (row_info->color_type == PNG_COLOR_TYPE_RGB) + if (row_info->bit_depth == 8) { - if (row_info->bit_depth == 8) - { #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + /* Notice that gamma to/from 1 are not necessarily inverses (if + * there is an overall gamma correction). Prior to 1.5.5 this code + * checked the linearized values for equality; this doesn't match + * the documentation, the original values must be checked. + */ + if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) { - png_bytep sp = row; - png_bytep dp = row; + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); - for (i = 0; i < row_width; i++) + if (red != green || red != blue) { - png_byte red = png_ptr->gamma_to_1[*(sp++)]; - png_byte green = png_ptr->gamma_to_1[*(sp++)]; - png_byte blue = png_ptr->gamma_to_1[*(sp++)]; + red = png_ptr->gamma_to_1[red]; + green = png_ptr->gamma_to_1[green]; + blue = png_ptr->gamma_to_1[blue]; - if (red != green || red != blue) - { - rgb_error |= 1; - *(dp++) = png_ptr->gamma_from_1[ - (rc*red + gc*green + bc*blue)>>15]; - } - - else - *(dp++) = *(sp - 1); + rgb_error |= 1; + *(dp++) = png_ptr->gamma_from_1[ + (rc*red + gc*green + bc*blue + 16384)>>15]; } - } - else -#endif - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_byte red = *(sp++); - png_byte green = *(sp++); - png_byte blue = *(sp++); - if (red != green || red != blue) - { - rgb_error |= 1; - *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); - } + else + { + /* If there is no overall correction the table will not be + * set. + */ + if (png_ptr->gamma_table != NULL) + red = png_ptr->gamma_table[red]; - else - *(dp++) = *(sp - 1); + *(dp++) = red; } + + if (have_alpha) + *(dp++) = *(sp++); } } - - else /* RGB bit_depth == 16 */ + else +#endif { -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->gamma_16_to_1 != NULL && - png_ptr->gamma_16_from_1 != NULL) - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 red, green, blue, w; - - red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - - if (red == green && red == blue) - w = red; - - else - { - png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) - >> png_ptr->gamma_shift][red>>8]; - png_uint_16 green_1 = - png_ptr->gamma_16_to_1[(green&0xff) >> - png_ptr->gamma_shift][green>>8]; - png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) - >> png_ptr->gamma_shift][blue>>8]; - png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 - + bc*blue_1)>>15); - w = png_ptr->gamma_16_from_1[(gray16&0xff) >> - png_ptr->gamma_shift][gray16 >> 8]; - rgb_error |= 1; - } + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; - *(dp++) = (png_byte)((w>>8) & 0xff); - *(dp++) = (png_byte)(w & 0xff); - } - } - else -#endif + for (i = 0; i < row_width; i++) { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 red, green, blue, gray16; + png_byte red = *(sp++); + png_byte green = *(sp++); + png_byte blue = *(sp++); - red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + if (red != green || red != blue) + { + rgb_error |= 1; + /*NOTE: this is the historical approach which simply + * truncates the results. + */ + *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); + } - if (red != green || red != blue) - rgb_error |= 1; + else + *(dp++) = red; - gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); - *(dp++) = (png_byte)((gray16>>8) & 0xff); - *(dp++) = (png_byte)(gray16 & 0xff); - } + if (have_alpha) + *(dp++) = *(sp++); } } } - if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + + else /* RGB bit_depth == 16 */ { - if (row_info->bit_depth == 8) - { #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) + if (png_ptr->gamma_16_to_1 != NULL && png_ptr->gamma_16_from_1 != NULL) + { + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; + + for (i = 0; i < row_width; i++) { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_byte red = png_ptr->gamma_to_1[*(sp++)]; - png_byte green = png_ptr->gamma_to_1[*(sp++)]; - png_byte blue = png_ptr->gamma_to_1[*(sp++)]; + png_uint_16 red, green, blue, w; - if (red != green || red != blue) - rgb_error |= 1; + red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - *(dp++) = png_ptr->gamma_from_1 - [(rc*red + gc*green + bc*blue)>>15]; + if (red == green && red == blue) + { + if (png_ptr->gamma_16_table != NULL) + w = png_ptr->gamma_16_table[(red&0xff) + >> png_ptr->gamma_shift][red>>8]; - *(dp++) = *(sp++); /* alpha */ + else + w = red; } - } - else -#endif - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) + + else { - png_byte red = *(sp++); - png_byte green = *(sp++); - png_byte blue = *(sp++); - if (red != green || red != blue) - rgb_error |= 1; - - *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); - *(dp++) = *(sp++); /* alpha */ + png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) + >> png_ptr->gamma_shift][red>>8]; + png_uint_16 green_1 = + png_ptr->gamma_16_to_1[(green&0xff) >> + png_ptr->gamma_shift][green>>8]; + png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) + >> png_ptr->gamma_shift][blue>>8]; + png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 + + bc*blue_1 + 16384)>>15); + w = png_ptr->gamma_16_from_1[(gray16&0xff) >> + png_ptr->gamma_shift][gray16 >> 8]; + rgb_error |= 1; + } + + *(dp++) = (png_byte)((w>>8) & 0xff); + *(dp++) = (png_byte)(w & 0xff); + + if (have_alpha) + { + *(dp++) = *(sp++); + *(dp++) = *(sp++); } } } - else /* RGBA bit_depth == 16 */ + else +#endif { -#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) - if (png_ptr->gamma_16_to_1 != NULL && - png_ptr->gamma_16_from_1 != NULL) - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) - { - png_uint_16 red, green, blue, w; - - red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - - if (red == green && red == blue) - w = red; - - else - { - png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> - png_ptr->gamma_shift][red>>8]; - - png_uint_16 green_1 = - png_ptr->gamma_16_to_1[(green&0xff) >> - png_ptr->gamma_shift][green>>8]; + png_bytep sp = row; + png_bytep dp = row; + png_uint_32 i; - png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> - png_ptr->gamma_shift][blue>>8]; + for (i = 0; i < row_width; i++) + { + png_uint_16 red, green, blue, gray16; - png_uint_16 gray16 = (png_uint_16)((rc * red_1 - + gc * green_1 + bc * blue_1)>>15); + red = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + green = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; + blue = (png_uint_16)(((*(sp))<<8) | *(sp + 1)); sp += 2; - w = png_ptr->gamma_16_from_1[(gray16&0xff) >> - png_ptr->gamma_shift][gray16 >> 8]; + if (red != green || red != blue) + rgb_error |= 1; - rgb_error |= 1; - } + /* From 1.5.5 in the 16 bit case do the accurate conversion even + * in the 'fast' case - this is because this is where the code + * ends up when handling linear 16 bit data. + */ + gray16 = (png_uint_16)((rc*red + gc*green + bc*blue + 16384) >> + 15); + *(dp++) = (png_byte)((gray16>>8) & 0xff); + *(dp++) = (png_byte)(gray16 & 0xff); - *(dp++) = (png_byte)((w>>8) & 0xff); - *(dp++) = (png_byte)(w & 0xff); - *(dp++) = *(sp++); /* alpha */ - *(dp++) = *(sp++); - } - } - else -#endif - { - png_bytep sp = row; - png_bytep dp = row; - for (i = 0; i < row_width; i++) + if (have_alpha) { - png_uint_16 red, green, blue, gray16; - red = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; - green = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; - blue = (png_uint_16)((*(sp)<<8) | *(sp + 1)); sp += 2; - - if (red != green || red != blue) - rgb_error |= 1; - - gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); - *(dp++) = (png_byte)((gray16>>8) & 0xff); - *(dp++) = (png_byte)(gray16 & 0xff); - *(dp++) = *(sp++); /* alpha */ + *(dp++) = *(sp++); *(dp++) = *(sp++); } } } } - row_info->channels -= 2; + + row_info->channels = (png_byte)(row_info->channels - 2); row_info->color_type = (png_byte)(row_info->color_type & ~PNG_COLOR_MASK_COLOR); row_info->pixel_depth = (png_byte)(row_info->channels * @@ -3400,7 +3476,8 @@ png_build_grayscale_palette(int bit_depth, png_colorp palette) #ifdef PNG_READ_TRANSFORMS_SUPPORTED -#ifdef PNG_READ_BACKGROUND_SUPPORTED +#if (defined PNG_READ_BACKGROUND_SUPPORTED) ||\ + (defined PNG_READ_ALPHA_MODE_SUPPORTED) /* Replace any alpha or transparency with the supplied background color. * "background" is already in the screen gamma, while "background_1" is * at a gamma of 1.0. Paletted files have already been taken care of. @@ -4108,7 +4185,7 @@ png_do_compose(png_row_infop row_info, png_bytep row, png_structp png_ptr) } } } -#endif +#endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_READ_ALPHA_MODE_SUPPORTED */ #ifdef PNG_READ_GAMMA_SUPPORTED /* Gamma correct the image, avoiding the alpha channel. Make sure @@ -4764,7 +4841,7 @@ png_do_expand(png_row_infop row_info, png_bytep row, #endif #ifdef PNG_READ_EXPAND_16_SUPPORTED -/* If the bit depth is 8 and the colour type is not a palette type expand the +/* If the bit depth is 8 and the color type is not a palette type expand the * whole row to 16 bits. Has no effect otherwise. */ void /* PRIVATE */ @@ -4941,8 +5018,8 @@ png_do_read_intrapixel(png_row_infop row_info, png_bytep row) png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); - png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL); - png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL); + png_uint_32 red = (s0 + s1 + 65536) & 0xffff; + png_uint_32 blue = (s2 + s1 + 65536) & 0xffff; *(rp ) = (png_byte)((red >> 8) & 0xff); *(rp + 1) = (png_byte)(red & 0xff); *(rp + 4) = (png_byte)((blue >> 8) & 0xff); @@ -4953,4 +5030,3 @@ png_do_read_intrapixel(png_row_infop row_info, png_bytep row) } #endif /* PNG_MNG_FEATURES_SUPPORTED */ #endif /* PNG_READ_SUPPORTED */ -} // namespace PrivatePng |