+++ /dev/null
-/*
- * rdcolmap.c
- *
- * Copyright (C) 1994-1996, Thomas G. Lane.
- * This file is part of the Independent JPEG Group's software.
- * For conditions of distribution and use, see the accompanying README file.
- *
- * This file implements djpeg's "-map file" switch. It reads a source image
- * and constructs a colormap to be supplied to the JPEG decompressor.
- *
- * Currently, these file formats are supported for the map file:
- * GIF: the contents of the GIF's global colormap are used.
- * PPM (either text or raw flavor): the entire file is read and
- * each unique pixel value is entered in the map.
- * Note that reading a large PPM file will be horrendously slow.
- * Typically, a PPM-format map file should contain just one pixel
- * of each desired color. Such a file can be extracted from an
- * ordinary image PPM file with ppmtomap(1).
- *
- * Rescaling a PPM that has a maxval unequal to MAXJSAMPLE is not
- * currently implemented.
- */
-
-#include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
-
-#ifdef QUANT_2PASS_SUPPORTED /* otherwise can't quantize to supplied map */
-
-/* Portions of this code are based on the PBMPLUS library, which is:
-**
-** Copyright (C) 1988 by Jef Poskanzer.
-**
-** Permission to use, copy, modify, and distribute this software and its
-** documentation for any purpose and without fee is hereby granted, provided
-** that the above copyright notice appear in all copies and that both that
-** copyright notice and this permission notice appear in supporting
-** documentation. This software is provided "as is" without express or
-** implied warranty.
-*/
-
-
-/*
- * Add a (potentially) new color to the color map.
- */
-
-LOCAL(void)
-add_map_entry (j_decompress_ptr cinfo, int R, int G, int B)
-{
- JSAMPROW colormap0 = cinfo->colormap[0];
- JSAMPROW colormap1 = cinfo->colormap[1];
- JSAMPROW colormap2 = cinfo->colormap[2];
- int ncolors = cinfo->actual_number_of_colors;
- int index;
-
- /* Check for duplicate color. */
- for (index = 0; index < ncolors; index++) {
- if (GETJSAMPLE(colormap0[index]) == R &&
- GETJSAMPLE(colormap1[index]) == G &&
- GETJSAMPLE(colormap2[index]) == B)
- return; /* color is already in map */
- }
-
- /* Check for map overflow. */
- if (ncolors >= (MAXJSAMPLE+1))
- ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, (MAXJSAMPLE+1));
-
- /* OK, add color to map. */
- colormap0[ncolors] = (JSAMPLE) R;
- colormap1[ncolors] = (JSAMPLE) G;
- colormap2[ncolors] = (JSAMPLE) B;
- cinfo->actual_number_of_colors++;
-}
-
-
-/*
- * Extract color map from a GIF file.
- */
-
-LOCAL(void)
-read_gif_map (j_decompress_ptr cinfo, FILE * infile)
-{
- int header[13];
- int i, colormaplen;
- int R, G, B;
-
- /* Initial 'G' has already been read by read_color_map */
- /* Read the rest of the GIF header and logical screen descriptor */
- for (i = 1; i < 13; i++) {
- if ((header[i] = getc(infile)) == EOF)
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
- }
-
- /* Verify GIF Header */
- if (header[1] != 'I' || header[2] != 'F')
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
-
- /* There must be a global color map. */
- if ((header[10] & 0x80) == 0)
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
-
- /* OK, fetch it. */
- colormaplen = 2 << (header[10] & 0x07);
-
- for (i = 0; i < colormaplen; i++) {
- R = getc(infile);
- G = getc(infile);
- B = getc(infile);
- if (R == EOF || G == EOF || B == EOF)
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
- add_map_entry(cinfo,
- R << (BITS_IN_JSAMPLE-8),
- G << (BITS_IN_JSAMPLE-8),
- B << (BITS_IN_JSAMPLE-8));
- }
-}
-
-
-/* Support routines for reading PPM */
-
-
-LOCAL(int)
-pbm_getc (FILE * infile)
-/* Read next char, skipping over any comments */
-/* A comment/newline sequence is returned as a newline */
-{
- register int ch;
-
- ch = getc(infile);
- if (ch == '#') {
- do {
- ch = getc(infile);
- } while (ch != '\n' && ch != EOF);
- }
- return ch;
-}
-
-
-LOCAL(unsigned int)
-read_pbm_integer (j_decompress_ptr cinfo, FILE * infile)
-/* Read an unsigned decimal integer from the PPM file */
-/* Swallows one trailing character after the integer */
-/* Note that on a 16-bit-int machine, only values up to 64k can be read. */
-/* This should not be a problem in practice. */
-{
- register int ch;
- register unsigned int val;
-
- /* Skip any leading whitespace */
- do {
- ch = pbm_getc(infile);
- if (ch == EOF)
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
- } while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r');
-
- if (ch < '0' || ch > '9')
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
-
- val = ch - '0';
- while ((ch = pbm_getc(infile)) >= '0' && ch <= '9') {
- val *= 10;
- val += ch - '0';
- }
- return val;
-}
-
-
-/*
- * Extract color map from a PPM file.
- */
-
-LOCAL(void)
-read_ppm_map (j_decompress_ptr cinfo, FILE * infile)
-{
- int c;
- unsigned int w, h, maxval, row, col;
- int R, G, B;
-
- /* Initial 'P' has already been read by read_color_map */
- c = getc(infile); /* save format discriminator for a sec */
-
- /* while we fetch the remaining header info */
- w = read_pbm_integer(cinfo, infile);
- h = read_pbm_integer(cinfo, infile);
- maxval = read_pbm_integer(cinfo, infile);
-
- if (w <= 0 || h <= 0 || maxval <= 0) /* error check */
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
-
- /* For now, we don't support rescaling from an unusual maxval. */
- if (maxval != (unsigned int) MAXJSAMPLE)
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
-
- switch (c) {
- case '3': /* it's a text-format PPM file */
- for (row = 0; row < h; row++) {
- for (col = 0; col < w; col++) {
- R = read_pbm_integer(cinfo, infile);
- G = read_pbm_integer(cinfo, infile);
- B = read_pbm_integer(cinfo, infile);
- add_map_entry(cinfo, R, G, B);
- }
- }
- break;
-
- case '6': /* it's a raw-format PPM file */
- for (row = 0; row < h; row++) {
- for (col = 0; col < w; col++) {
- R = getc(infile);
- G = getc(infile);
- B = getc(infile);
- if (R == EOF || G == EOF || B == EOF)
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
- add_map_entry(cinfo, R, G, B);
- }
- }
- break;
-
- default:
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
- break;
- }
-}
-
-
-/*
- * Main entry point from djpeg.c.
- * Input: opened input file (from file name argument on command line).
- * Output: colormap and actual_number_of_colors fields are set in cinfo.
- */
-
-GLOBAL(void)
-read_color_map (j_decompress_ptr cinfo, FILE * infile)
-{
- /* Allocate space for a color map of maximum supported size. */
- cinfo->colormap = (*cinfo->mem->alloc_sarray)
- ((j_common_ptr) cinfo, JPOOL_IMAGE,
- (JDIMENSION) (MAXJSAMPLE+1), (JDIMENSION) 3);
- cinfo->actual_number_of_colors = 0; /* initialize map to empty */
-
- /* Read first byte to determine file format */
- switch (getc(infile)) {
- case 'G':
- read_gif_map(cinfo, infile);
- break;
- case 'P':
- read_ppm_map(cinfo, infile);
- break;
- default:
- ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
- break;
- }
-}
-
-#endif /* QUANT_2PASS_SUPPORTED */
projects / synfig.git / blobdiff