+++ /dev/null
-
-/* pngwtran.c - transforms the data in a row for PNG writers
- *
- * Last changed in libpng 1.2.9 April 14, 2006
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1998-2006 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.)
- */
-
-#define PNG_INTERNAL
-#include "png.h"
-#ifdef PNG_WRITE_SUPPORTED
-
-/* Transform the data according to the user's wishes. The order of
- * transformations is significant.
- */
-void /* PRIVATE */
-png_do_write_transformations(png_structp png_ptr)
-{
- png_debug(1, "in png_do_write_transformations\n");
-
- if (png_ptr == NULL)
- return;
-
-#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED)
- if (png_ptr->transformations & PNG_USER_TRANSFORM)
- if(png_ptr->write_user_transform_fn != NULL)
- (*(png_ptr->write_user_transform_fn)) /* user write transform function */
- (png_ptr, /* png_ptr */
- &(png_ptr->row_info), /* row_info: */
- /* png_uint_32 width; width of row */
- /* png_uint_32 rowbytes; number of bytes in row */
- /* png_byte color_type; color type of pixels */
- /* png_byte bit_depth; bit depth of samples */
- /* png_byte channels; number of channels (1-4) */
- /* png_byte pixel_depth; bits per pixel (depth*channels) */
- png_ptr->row_buf + 1); /* start of pixel data for row */
-#endif
-#if defined(PNG_WRITE_FILLER_SUPPORTED)
- if (png_ptr->transformations & PNG_FILLER)
- png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1,
- png_ptr->flags);
-#endif
-#if defined(PNG_WRITE_PACKSWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_PACKSWAP)
- png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-#if defined(PNG_WRITE_PACK_SUPPORTED)
- if (png_ptr->transformations & PNG_PACK)
- png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1,
- (png_uint_32)png_ptr->bit_depth);
-#endif
-#if defined(PNG_WRITE_SWAP_SUPPORTED)
- if (png_ptr->transformations & PNG_SWAP_BYTES)
- png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-#if defined(PNG_WRITE_SHIFT_SUPPORTED)
- if (png_ptr->transformations & PNG_SHIFT)
- png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1,
- &(png_ptr->shift));
-#endif
-#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
- if (png_ptr->transformations & PNG_SWAP_ALPHA)
- png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
- if (png_ptr->transformations & PNG_INVERT_ALPHA)
- png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-#if defined(PNG_WRITE_BGR_SUPPORTED)
- if (png_ptr->transformations & PNG_BGR)
- png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-#if defined(PNG_WRITE_INVERT_SUPPORTED)
- if (png_ptr->transformations & PNG_INVERT_MONO)
- png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-}
-
-#if defined(PNG_WRITE_PACK_SUPPORTED)
-/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The
- * row_info bit depth should be 8 (one pixel per byte). The channels
- * should be 1 (this only happens on grayscale and paletted images).
- */
-void /* PRIVATE */
-png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth)
-{
- png_debug(1, "in png_do_pack\n");
- if (row_info->bit_depth == 8 &&
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- row_info->channels == 1)
- {
- switch ((int)bit_depth)
- {
- case 1:
- {
- png_bytep sp, dp;
- int mask, v;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- sp = row;
- dp = row;
- mask = 0x80;
- v = 0;
-
- for (i = 0; i < row_width; i++)
- {
- if (*sp != 0)
- v |= mask;
- sp++;
- if (mask > 1)
- mask >>= 1;
- else
- {
- mask = 0x80;
- *dp = (png_byte)v;
- dp++;
- v = 0;
- }
- }
- if (mask != 0x80)
- *dp = (png_byte)v;
- break;
- }
- case 2:
- {
- png_bytep sp, dp;
- int shift, v;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- sp = row;
- dp = row;
- shift = 6;
- v = 0;
- for (i = 0; i < row_width; i++)
- {
- png_byte value;
-
- value = (png_byte)(*sp & 0x03);
- v |= (value << shift);
- if (shift == 0)
- {
- shift = 6;
- *dp = (png_byte)v;
- dp++;
- v = 0;
- }
- else
- shift -= 2;
- sp++;
- }
- if (shift != 6)
- *dp = (png_byte)v;
- break;
- }
- case 4:
- {
- png_bytep sp, dp;
- int shift, v;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- sp = row;
- dp = row;
- shift = 4;
- v = 0;
- for (i = 0; i < row_width; i++)
- {
- png_byte value;
-
- value = (png_byte)(*sp & 0x0f);
- v |= (value << shift);
-
- if (shift == 0)
- {
- shift = 4;
- *dp = (png_byte)v;
- dp++;
- v = 0;
- }
- else
- shift -= 4;
-
- sp++;
- }
- if (shift != 4)
- *dp = (png_byte)v;
- break;
- }
- }
- row_info->bit_depth = (png_byte)bit_depth;
- row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels);
- row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
- row_info->width);
- }
-}
-#endif
-
-#if defined(PNG_WRITE_SHIFT_SUPPORTED)
-/* Shift pixel values to take advantage of whole range. Pass the
- * true number of bits in bit_depth. The row should be packed
- * according to row_info->bit_depth. Thus, if you had a row of
- * bit depth 4, but the pixels only had values from 0 to 7, you
- * would pass 3 as bit_depth, and this routine would translate the
- * data to 0 to 15.
- */
-void /* PRIVATE */
-png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth)
-{
- png_debug(1, "in png_do_shift\n");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL &&
-#else
- if (
-#endif
- row_info->color_type != PNG_COLOR_TYPE_PALETTE)
- {
- int shift_start[4], shift_dec[4];
- int channels = 0;
-
- if (row_info->color_type & PNG_COLOR_MASK_COLOR)
- {
- shift_start[channels] = row_info->bit_depth - bit_depth->red;
- shift_dec[channels] = bit_depth->red;
- channels++;
- shift_start[channels] = row_info->bit_depth - bit_depth->green;
- shift_dec[channels] = bit_depth->green;
- channels++;
- shift_start[channels] = row_info->bit_depth - bit_depth->blue;
- shift_dec[channels] = bit_depth->blue;
- channels++;
- }
- else
- {
- shift_start[channels] = row_info->bit_depth - bit_depth->gray;
- shift_dec[channels] = bit_depth->gray;
- channels++;
- }
- if (row_info->color_type & PNG_COLOR_MASK_ALPHA)
- {
- shift_start[channels] = row_info->bit_depth - bit_depth->alpha;
- shift_dec[channels] = bit_depth->alpha;
- channels++;
- }
-
- /* with low row depths, could only be grayscale, so one channel */
- if (row_info->bit_depth < 8)
- {
- png_bytep bp = row;
- png_uint_32 i;
- png_byte mask;
- png_uint_32 row_bytes = row_info->rowbytes;
-
- if (bit_depth->gray == 1 && row_info->bit_depth == 2)
- mask = 0x55;
- else if (row_info->bit_depth == 4 && bit_depth->gray == 3)
- mask = 0x11;
- else
- mask = 0xff;
-
- for (i = 0; i < row_bytes; i++, bp++)
- {
- png_uint_16 v;
- int j;
-
- v = *bp;
- *bp = 0;
- for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0])
- {
- if (j > 0)
- *bp |= (png_byte)((v << j) & 0xff);
- else
- *bp |= (png_byte)((v >> (-j)) & mask);
- }
- }
- }
- else if (row_info->bit_depth == 8)
- {
- png_bytep bp = row;
- png_uint_32 i;
- png_uint_32 istop = channels * row_info->width;
-
- for (i = 0; i < istop; i++, bp++)
- {
-
- png_uint_16 v;
- int j;
- int c = (int)(i%channels);
-
- v = *bp;
- *bp = 0;
- for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
- {
- if (j > 0)
- *bp |= (png_byte)((v << j) & 0xff);
- else
- *bp |= (png_byte)((v >> (-j)) & 0xff);
- }
- }
- }
- else
- {
- png_bytep bp;
- png_uint_32 i;
- png_uint_32 istop = channels * row_info->width;
-
- for (bp = row, i = 0; i < istop; i++)
- {
- int c = (int)(i%channels);
- png_uint_16 value, v;
- int j;
-
- v = (png_uint_16)(((png_uint_16)(*bp) << 8) + *(bp + 1));
- value = 0;
- for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c])
- {
- if (j > 0)
- value |= (png_uint_16)((v << j) & (png_uint_16)0xffff);
- else
- value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff);
- }
- *bp++ = (png_byte)(value >> 8);
- *bp++ = (png_byte)(value & 0xff);
- }
- }
- }
-}
-#endif
-
-#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED)
-void /* PRIVATE */
-png_do_write_swap_alpha(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_write_swap_alpha\n");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- /* This converts from ARGB to RGBA */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- png_byte save = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = save;
- }
- }
- /* This converts from AARRGGBB to RRGGBBAA */
- else
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- png_byte save[2];
- save[0] = *(sp++);
- save[1] = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = save[0];
- *(dp++) = save[1];
- }
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- /* This converts from AG to GA */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- png_byte save = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = save;
- }
- }
- /* This converts from AAGG to GGAA */
- else
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- png_byte save[2];
- save[0] = *(sp++);
- save[1] = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = save[0];
- *(dp++) = save[1];
- }
- }
- }
- }
-}
-#endif
-
-#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED)
-void /* PRIVATE */
-png_do_write_invert_alpha(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_write_invert_alpha\n");
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- if (row != NULL && row_info != NULL)
-#endif
- {
- if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- {
- /* This inverts the alpha channel in RGBA */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- /* does nothing
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- */
- sp+=3; dp = sp;
- *(dp++) = (png_byte)(255 - *(sp++));
- }
- }
- /* This inverts the alpha channel in RRGGBBAA */
- else
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- /* does nothing
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- */
- sp+=6; dp = sp;
- *(dp++) = (png_byte)(255 - *(sp++));
- *(dp++) = (png_byte)(255 - *(sp++));
- }
- }
- }
- else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
- {
- /* This inverts the alpha channel in GA */
- if (row_info->bit_depth == 8)
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- *(dp++) = *(sp++);
- *(dp++) = (png_byte)(255 - *(sp++));
- }
- }
- /* This inverts the alpha channel in GGAA */
- else
- {
- png_bytep sp, dp;
- png_uint_32 i;
- png_uint_32 row_width = row_info->width;
-
- for (i = 0, sp = dp = row; i < row_width; i++)
- {
- /* does nothing
- *(dp++) = *(sp++);
- *(dp++) = *(sp++);
- */
- sp+=2; dp = sp;
- *(dp++) = (png_byte)(255 - *(sp++));
- *(dp++) = (png_byte)(255 - *(sp++));
- }
- }
- }
- }
-}
-#endif
-
-#if defined(PNG_MNG_FEATURES_SUPPORTED)
-/* undoes intrapixel differencing */
-void /* PRIVATE */
-png_do_write_intrapixel(png_row_infop row_info, png_bytep row)
-{
- png_debug(1, "in png_do_write_intrapixel\n");
- if (
-#if defined(PNG_USELESS_TESTS_SUPPORTED)
- row != NULL && row_info != NULL &&
-#endif
- (row_info->color_type & PNG_COLOR_MASK_COLOR))
- {
- int bytes_per_pixel;
- png_uint_32 row_width = row_info->width;
- if (row_info->bit_depth == 8)
- {
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 3;
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 4;
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- *(rp) = (png_byte)((*rp - *(rp+1))&0xff);
- *(rp+2) = (png_byte)((*(rp+2) - *(rp+1))&0xff);
- }
- }
- else if (row_info->bit_depth == 16)
- {
- png_bytep rp;
- png_uint_32 i;
-
- if (row_info->color_type == PNG_COLOR_TYPE_RGB)
- bytes_per_pixel = 6;
- else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
- bytes_per_pixel = 8;
- else
- return;
-
- for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel)
- {
- 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) & 0xffffL);
- png_uint_32 blue = (png_uint_32)((s2-s1) & 0xffffL);
- *(rp ) = (png_byte)((red >> 8) & 0xff);
- *(rp+1) = (png_byte)(red & 0xff);
- *(rp+4) = (png_byte)((blue >> 8) & 0xff);
- *(rp+5) = (png_byte)(blue & 0xff);
- }
- }
- }
-}
-#endif /* PNG_MNG_FEATURES_SUPPORTED */
-#endif /* PNG_WRITE_SUPPORTED */
projects / opencv / blobdiff