rdcolmap.c
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1 /*
2  * rdcolmap.c
3  *
4  * Copyright (C) 1994-1996, Thomas G. Lane.
5  * This file is part of the Independent JPEG Group's software.
6  * For conditions of distribution and use, see the accompanying README file.
7  *
8  * This file implements djpeg's "-map file" switch. It reads a source image
9  * and constructs a colormap to be supplied to the JPEG decompressor.
10  *
11  * Currently, these file formats are supported for the map file:
12  * GIF: the contents of the GIF's global colormap are used.
13  * PPM (either text or raw flavor): the entire file is read and
14  * each unique pixel value is entered in the map.
15  * Note that reading a large PPM file will be horrendously slow.
16  * Typically, a PPM-format map file should contain just one pixel
17  * of each desired color. Such a file can be extracted from an
18  * ordinary image PPM file with ppmtomap(1).
19  *
20  * Rescaling a PPM that has a maxval unequal to MAXJSAMPLE is not
21  * currently implemented.
22  */
23 
24 #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
25 
26 #ifdef QUANT_2PASS_SUPPORTED /* otherwise can't quantize to supplied map */
27 
28 /* Portions of this code are based on the PBMPLUS library, which is:
29 **
30 ** Copyright (C) 1988 by Jef Poskanzer.
31 **
32 ** Permission to use, copy, modify, and distribute this software and its
33 ** documentation for any purpose and without fee is hereby granted, provided
34 ** that the above copyright notice appear in all copies and that both that
35 ** copyright notice and this permission notice appear in supporting
36 ** documentation. This software is provided "as is" without express or
37 ** implied warranty.
38 */
39 
40 
41 /*
42  * Add a (potentially) new color to the color map.
43  */
44 
45 LOCAL(void)
46 add_map_entry (j_decompress_ptr cinfo, int R, int G, int B)
47 {
48  JSAMPROW colormap0 = cinfo->colormap[0];
49  JSAMPROW colormap1 = cinfo->colormap[1];
50  JSAMPROW colormap2 = cinfo->colormap[2];
51  int ncolors = cinfo->actual_number_of_colors;
52  int index;
53 
54  /* Check for duplicate color. */
55  for (index = 0; index < ncolors; index++) {
56  if (GETJSAMPLE(colormap0[index]) == R &&
57  GETJSAMPLE(colormap1[index]) == G &&
58  GETJSAMPLE(colormap2[index]) == B)
59  return; /* color is already in map */
60  }
61 
62  /* Check for map overflow. */
63  if (ncolors >= (MAXJSAMPLE+1))
64  ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, (MAXJSAMPLE+1));
65 
66  /* OK, add color to map. */
67  colormap0[ncolors] = (JSAMPLE) R;
68  colormap1[ncolors] = (JSAMPLE) G;
69  colormap2[ncolors] = (JSAMPLE) B;
70  cinfo->actual_number_of_colors++;
71 }
72 
73 
74 /*
75  * Extract color map from a GIF file.
76  */
77 
78 LOCAL(void)
80 {
81  int header[13];
82  int i, colormaplen;
83  int R, G, B;
84 
85  /* Initial 'G' has already been read by read_color_map */
86  /* Read the rest of the GIF header and logical screen descriptor */
87  for (i = 1; i < 13; i++) {
88  if ((header[i] = getc(infile)) == EOF)
89  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
90  }
91 
92  /* Verify GIF Header */
93  if (header[1] != 'I' || header[2] != 'F')
94  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
95 
96  /* There must be a global color map. */
97  if ((header[10] & 0x80) == 0)
98  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
99 
100  /* OK, fetch it. */
101  colormaplen = 2 << (header[10] & 0x07);
102 
103  for (i = 0; i < colormaplen; i++) {
104  R = getc(infile);
105  G = getc(infile);
106  B = getc(infile);
107  if (R == EOF || G == EOF || B == EOF)
108  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
109  add_map_entry(cinfo,
110  R << (BITS_IN_JSAMPLE-8),
111  G << (BITS_IN_JSAMPLE-8),
112  B << (BITS_IN_JSAMPLE-8));
113  }
114 }
115 
116 
117 /* Support routines for reading PPM */
118 
119 
120 LOCAL(int)
121 pbm_getc (FILE * infile)
122 /* Read next char, skipping over any comments */
123 /* A comment/newline sequence is returned as a newline */
124 {
125  register int ch;
126 
127  ch = getc(infile);
128  if (ch == '#') {
129  do {
130  ch = getc(infile);
131  } while (ch != '\n' && ch != EOF);
132  }
133  return ch;
134 }
135 
136 
137 LOCAL(unsigned int)
139 /* Read an unsigned decimal integer from the PPM file */
140 /* Swallows one trailing character after the integer */
141 /* Note that on a 16-bit-int machine, only values up to 64k can be read. */
142 /* This should not be a problem in practice. */
143 {
144  register int ch;
145  register unsigned int val;
146 
147  /* Skip any leading whitespace */
148  do {
149  ch = pbm_getc(infile);
150  if (ch == EOF)
151  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
152  } while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r');
153 
154  if (ch < '0' || ch > '9')
155  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
156 
157  val = ch - '0';
158  while ((ch = pbm_getc(infile)) >= '0' && ch <= '9') {
159  val *= 10;
160  val += ch - '0';
161  }
162  return val;
163 }
164 
165 
166 /*
167  * Extract color map from a PPM file.
168  */
169 
170 LOCAL(void)
172 {
173  int c;
174  unsigned int w, h, maxval, row, col;
175  int R, G, B;
176 
177  /* Initial 'P' has already been read by read_color_map */
178  c = getc(infile); /* save format discriminator for a sec */
179 
180  /* while we fetch the remaining header info */
181  w = read_pbm_integer(cinfo, infile);
182  h = read_pbm_integer(cinfo, infile);
183  maxval = read_pbm_integer(cinfo, infile);
184 
185  if (w <= 0 || h <= 0 || maxval <= 0) /* error check */
186  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
187 
188  /* For now, we don't support rescaling from an unusual maxval. */
189  if (maxval != (unsigned int) MAXJSAMPLE)
190  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
191 
192  switch (c) {
193  case '3': /* it's a text-format PPM file */
194  for (row = 0; row < h; row++) {
195  for (col = 0; col < w; col++) {
196  R = read_pbm_integer(cinfo, infile);
197  G = read_pbm_integer(cinfo, infile);
198  B = read_pbm_integer(cinfo, infile);
199  add_map_entry(cinfo, R, G, B);
200  }
201  }
202  break;
203 
204  case '6': /* it's a raw-format PPM file */
205  for (row = 0; row < h; row++) {
206  for (col = 0; col < w; col++) {
207  R = getc(infile);
208  G = getc(infile);
209  B = getc(infile);
210  if (R == EOF || G == EOF || B == EOF)
211  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
212  add_map_entry(cinfo, R, G, B);
213  }
214  }
215  break;
216 
217  default:
218  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
219  break;
220  }
221 }
222 
223 
224 /*
225  * Main entry point from djpeg.c.
226  * Input: opened input file (from file name argument on command line).
227  * Output: colormap and actual_number_of_colors fields are set in cinfo.
228  */
229 
230 GLOBAL(void)
232 {
233  /* Allocate space for a color map of maximum supported size. */
234  cinfo->colormap = (*cinfo->mem->alloc_sarray)
235  ((j_common_ptr) cinfo, JPOOL_IMAGE,
236  (JDIMENSION) (MAXJSAMPLE+1), (JDIMENSION) 3);
237  cinfo->actual_number_of_colors = 0; /* initialize map to empty */
238 
239  /* Read first byte to determine file format */
240  switch (getc(infile)) {
241  case 'G':
242  read_gif_map(cinfo, infile);
243  break;
244  case 'P':
245  read_ppm_map(cinfo, infile);
246  break;
247  default:
248  ERREXIT(cinfo, JERR_BAD_CMAP_FILE);
249  break;
250  }
251 }
252 
253 #endif /* QUANT_2PASS_SUPPORTED */
add_map_entry(j_decompress_ptr cinfo, int R, int G, int B)
Definition: rdcolmap.c:46
#define BITS_IN_JSAMPLE
Definition: jmorecfg.h:23
int c
Definition: autoplay.py:16
char JSAMPLE
Definition: jmorecfg.h:64
JSAMPLE FAR * JSAMPROW
Definition: jpeglib.h:66
#define GETJSAMPLE(value)
Definition: jmorecfg.h:68
#define ERREXIT(cinfo, code)
Definition: jerror.h:205
read_pbm_integer(j_decompress_ptr cinfo, FILE *infile)
Definition: rdcolmap.c:138
#define MAXJSAMPLE
Definition: jmorecfg.h:73
read_color_map(j_decompress_ptr cinfo, FILE *infile)
Definition: rdcolmap.c:231
w
png_uint_32 i
Definition: png.h:2735
pbm_getc(FILE *infile)
Definition: rdcolmap.c:121
#define JPOOL_IMAGE
Definition: jpeglib.h:749
#define LOCAL(type)
Definition: jmorecfg.h:186
read_ppm_map(j_decompress_ptr cinfo, FILE *infile)
Definition: rdcolmap.c:171
list index
int val
Definition: jpeglib.h:956
png_bytepp row
Definition: png.h:1759
read_gif_map(j_decompress_ptr cinfo, FILE *infile)
Definition: rdcolmap.c:79
#define ERREXIT1(cinfo, code, p1)
Definition: jerror.h:208
#define GLOBAL(type)
Definition: jmorecfg.h:188
FILE * infile
Definition: cdjpeg.h:141
unsigned int JDIMENSION
Definition: jmorecfg.h:171


openhrp3
Author(s): AIST, General Robotix Inc., Nakamura Lab of Dept. of Mechano Informatics at University of Tokyo
autogenerated on Thu Sep 8 2022 02:24:05