rdppm.c
Go to the documentation of this file.
1 /*
2  * rdppm.c
3  *
4  * Copyright (C) 1991-1997, 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 contains routines to read input images in PPM/PGM format.
9  * The extended 2-byte-per-sample raw PPM/PGM formats are supported.
10  * The PBMPLUS library is NOT required to compile this software
11  * (but it is highly useful as a set of PPM image manipulation programs).
12  *
13  * These routines may need modification for non-Unix environments or
14  * specialized applications. As they stand, they assume input from
15  * an ordinary stdio stream. They further assume that reading begins
16  * at the start of the file; start_input may need work if the
17  * user interface has already read some data (e.g., to determine that
18  * the file is indeed PPM format).
19  */
20 
21 #include "cdjpeg.h" /* Common decls for cjpeg/djpeg applications */
22 
23 #ifdef PPM_SUPPORTED
24 
25 
26 /* Portions of this code are based on the PBMPLUS library, which is:
27 **
28 ** Copyright (C) 1988 by Jef Poskanzer.
29 **
30 ** Permission to use, copy, modify, and distribute this software and its
31 ** documentation for any purpose and without fee is hereby granted, provided
32 ** that the above copyright notice appear in all copies and that both that
33 ** copyright notice and this permission notice appear in supporting
34 ** documentation. This software is provided "as is" without express or
35 ** implied warranty.
36 */
37 
38 
39 /* Macros to deal with unsigned chars as efficiently as compiler allows */
40 
41 #ifdef HAVE_UNSIGNED_CHAR
42 typedef unsigned char U_CHAR;
43 #define UCH(x) ((int) (x))
44 #else /* !HAVE_UNSIGNED_CHAR */
45 #ifdef CHAR_IS_UNSIGNED
46 typedef char U_CHAR;
47 #define UCH(x) ((int) (x))
48 #else
49 typedef char U_CHAR;
50 #define UCH(x) ((int) (x) & 0xFF)
51 #endif
52 #endif /* HAVE_UNSIGNED_CHAR */
53 
54 
55 #define ReadOK(file,buffer,len) (JFREAD(file,buffer,len) == ((size_t) (len)))
56 
57 
58 /*
59  * On most systems, reading individual bytes with getc() is drastically less
60  * efficient than buffering a row at a time with fread(). On PCs, we must
61  * allocate the buffer in near data space, because we are assuming small-data
62  * memory model, wherein fread() can't reach far memory. If you need to
63  * process very wide images on a PC, you might have to compile in large-memory
64  * model, or else replace fread() with a getc() loop --- which will be much
65  * slower.
66  */
67 
68 
69 /* Private version of data source object */
70 
71 typedef struct {
72  struct cjpeg_source_struct pub; /* public fields */
73 
74  U_CHAR *iobuffer; /* non-FAR pointer to I/O buffer */
75  JSAMPROW pixrow; /* FAR pointer to same */
76  size_t buffer_width; /* width of I/O buffer */
77  JSAMPLE *rescale; /* => maxval-remapping array, or NULL */
79 
81 
82 
83 LOCAL(int)
84 pbm_getc (FILE * infile)
85 /* Read next char, skipping over any comments */
86 /* A comment/newline sequence is returned as a newline */
87 {
88  register int ch;
89 
90  ch = getc(infile);
91  if (ch == '#') {
92  do {
93  ch = getc(infile);
94  } while (ch != '\n' && ch != EOF);
95  }
96  return ch;
97 }
98 
99 
100 LOCAL(unsigned int)
102 /* Read an unsigned decimal integer from the PPM file */
103 /* Swallows one trailing character after the integer */
104 /* Note that on a 16-bit-int machine, only values up to 64k can be read. */
105 /* This should not be a problem in practice. */
106 {
107  register int ch;
108  register unsigned int val;
109 
110  /* Skip any leading whitespace */
111  do {
112  ch = pbm_getc(infile);
113  if (ch == EOF)
114  ERREXIT(cinfo, JERR_INPUT_EOF);
115  } while (ch == ' ' || ch == '\t' || ch == '\n' || ch == '\r');
116 
117  if (ch < '0' || ch > '9')
118  ERREXIT(cinfo, JERR_PPM_NONNUMERIC);
119 
120  val = ch - '0';
121  while ((ch = pbm_getc(infile)) >= '0' && ch <= '9') {
122  val *= 10;
123  val += ch - '0';
124  }
125  return val;
126 }
127 
128 
129 /*
130  * Read one row of pixels.
131  *
132  * We provide several different versions depending on input file format.
133  * In all cases, input is scaled to the size of JSAMPLE.
134  *
135  * A really fast path is provided for reading byte/sample raw files with
136  * maxval = MAXJSAMPLE, which is the normal case for 8-bit data.
137  */
138 
139 
142 /* This version is for reading text-format PGM files with any maxval */
143 {
144  ppm_source_ptr source = (ppm_source_ptr) sinfo;
145  FILE * infile = source->pub.input_file;
146  register JSAMPROW ptr;
147  register JSAMPLE *rescale = source->rescale;
148  JDIMENSION col;
149 
150  ptr = source->pub.buffer[0];
151  for (col = cinfo->image_width; col > 0; col--) {
152  *ptr++ = rescale[read_pbm_integer(cinfo, infile)];
153  }
154  return 1;
155 }
156 
157 
160 /* This version is for reading text-format PPM files with any maxval */
161 {
162  ppm_source_ptr source = (ppm_source_ptr) sinfo;
163  FILE * infile = source->pub.input_file;
164  register JSAMPROW ptr;
165  register JSAMPLE *rescale = source->rescale;
166  JDIMENSION col;
167 
168  ptr = source->pub.buffer[0];
169  for (col = cinfo->image_width; col > 0; col--) {
170  *ptr++ = rescale[read_pbm_integer(cinfo, infile)];
171  *ptr++ = rescale[read_pbm_integer(cinfo, infile)];
172  *ptr++ = rescale[read_pbm_integer(cinfo, infile)];
173  }
174  return 1;
175 }
176 
177 
180 /* This version is for reading raw-byte-format PGM files with any maxval */
181 {
182  ppm_source_ptr source = (ppm_source_ptr) sinfo;
183  register JSAMPROW ptr;
184  register U_CHAR * bufferptr;
185  register JSAMPLE *rescale = source->rescale;
186  JDIMENSION col;
187 
188  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
189  ERREXIT(cinfo, JERR_INPUT_EOF);
190  ptr = source->pub.buffer[0];
191  bufferptr = source->iobuffer;
192  for (col = cinfo->image_width; col > 0; col--) {
193  *ptr++ = rescale[UCH(*bufferptr++)];
194  }
195  return 1;
196 }
197 
198 
201 /* This version is for reading raw-byte-format PPM files with any maxval */
202 {
203  ppm_source_ptr source = (ppm_source_ptr) sinfo;
204  register JSAMPROW ptr;
205  register U_CHAR * bufferptr;
206  register JSAMPLE *rescale = source->rescale;
207  JDIMENSION col;
208 
209  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
210  ERREXIT(cinfo, JERR_INPUT_EOF);
211  ptr = source->pub.buffer[0];
212  bufferptr = source->iobuffer;
213  for (col = cinfo->image_width; col > 0; col--) {
214  *ptr++ = rescale[UCH(*bufferptr++)];
215  *ptr++ = rescale[UCH(*bufferptr++)];
216  *ptr++ = rescale[UCH(*bufferptr++)];
217  }
218  return 1;
219 }
220 
221 
224 /* This version is for reading raw-byte-format files with maxval = MAXJSAMPLE.
225  * In this case we just read right into the JSAMPLE buffer!
226  * Note that same code works for PPM and PGM files.
227  */
228 {
229  ppm_source_ptr source = (ppm_source_ptr) sinfo;
230 
231  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
232  ERREXIT(cinfo, JERR_INPUT_EOF);
233  return 1;
234 }
235 
236 
239 /* This version is for reading raw-word-format PGM files with any maxval */
240 {
241  ppm_source_ptr source = (ppm_source_ptr) sinfo;
242  register JSAMPROW ptr;
243  register U_CHAR * bufferptr;
244  register JSAMPLE *rescale = source->rescale;
245  JDIMENSION col;
246 
247  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
248  ERREXIT(cinfo, JERR_INPUT_EOF);
249  ptr = source->pub.buffer[0];
250  bufferptr = source->iobuffer;
251  for (col = cinfo->image_width; col > 0; col--) {
252  register int temp;
253  temp = UCH(*bufferptr++);
254  temp |= UCH(*bufferptr++) << 8;
255  *ptr++ = rescale[temp];
256  }
257  return 1;
258 }
259 
260 
263 /* This version is for reading raw-word-format PPM files with any maxval */
264 {
265  ppm_source_ptr source = (ppm_source_ptr) sinfo;
266  register JSAMPROW ptr;
267  register U_CHAR * bufferptr;
268  register JSAMPLE *rescale = source->rescale;
269  JDIMENSION col;
270 
271  if (! ReadOK(source->pub.input_file, source->iobuffer, source->buffer_width))
272  ERREXIT(cinfo, JERR_INPUT_EOF);
273  ptr = source->pub.buffer[0];
274  bufferptr = source->iobuffer;
275  for (col = cinfo->image_width; col > 0; col--) {
276  register int temp;
277  temp = UCH(*bufferptr++);
278  temp |= UCH(*bufferptr++) << 8;
279  *ptr++ = rescale[temp];
280  temp = UCH(*bufferptr++);
281  temp |= UCH(*bufferptr++) << 8;
282  *ptr++ = rescale[temp];
283  temp = UCH(*bufferptr++);
284  temp |= UCH(*bufferptr++) << 8;
285  *ptr++ = rescale[temp];
286  }
287  return 1;
288 }
289 
290 
291 /*
292  * Read the file header; return image size and component count.
293  */
294 
295 METHODDEF(void)
297 {
298  ppm_source_ptr source = (ppm_source_ptr) sinfo;
299  int c;
300  unsigned int w, h, maxval;
301  boolean need_iobuffer, use_raw_buffer, need_rescale;
302 
303  if (getc(source->pub.input_file) != 'P')
304  ERREXIT(cinfo, JERR_PPM_NOT);
305 
306  c = getc(source->pub.input_file); /* subformat discriminator character */
307 
308  /* detect unsupported variants (ie, PBM) before trying to read header */
309  switch (c) {
310  case '2': /* it's a text-format PGM file */
311  case '3': /* it's a text-format PPM file */
312  case '5': /* it's a raw-format PGM file */
313  case '6': /* it's a raw-format PPM file */
314  break;
315  default:
316  ERREXIT(cinfo, JERR_PPM_NOT);
317  break;
318  }
319 
320  /* fetch the remaining header info */
321  w = read_pbm_integer(cinfo, source->pub.input_file);
322  h = read_pbm_integer(cinfo, source->pub.input_file);
323  maxval = read_pbm_integer(cinfo, source->pub.input_file);
324 
325  if (w <= 0 || h <= 0 || maxval <= 0) /* error check */
326  ERREXIT(cinfo, JERR_PPM_NOT);
327 
328  cinfo->data_precision = BITS_IN_JSAMPLE; /* we always rescale data to this */
329  cinfo->image_width = (JDIMENSION) w;
330  cinfo->image_height = (JDIMENSION) h;
331 
332  /* initialize flags to most common settings */
333  need_iobuffer = TRUE; /* do we need an I/O buffer? */
334  use_raw_buffer = FALSE; /* do we map input buffer onto I/O buffer? */
335  need_rescale = TRUE; /* do we need a rescale array? */
336 
337  switch (c) {
338  case '2': /* it's a text-format PGM file */
339  cinfo->input_components = 1;
340  cinfo->in_color_space = JCS_GRAYSCALE;
341  TRACEMS2(cinfo, 1, JTRC_PGM_TEXT, w, h);
342  source->pub.get_pixel_rows = get_text_gray_row;
343  need_iobuffer = FALSE;
344  break;
345 
346  case '3': /* it's a text-format PPM file */
347  cinfo->input_components = 3;
348  cinfo->in_color_space = JCS_RGB;
349  TRACEMS2(cinfo, 1, JTRC_PPM_TEXT, w, h);
350  source->pub.get_pixel_rows = get_text_rgb_row;
351  need_iobuffer = FALSE;
352  break;
353 
354  case '5': /* it's a raw-format PGM file */
355  cinfo->input_components = 1;
356  cinfo->in_color_space = JCS_GRAYSCALE;
357  TRACEMS2(cinfo, 1, JTRC_PGM, w, h);
358  if (maxval > 255) {
359  source->pub.get_pixel_rows = get_word_gray_row;
360  } else if (maxval == MAXJSAMPLE && SIZEOF(JSAMPLE) == SIZEOF(U_CHAR)) {
361  source->pub.get_pixel_rows = get_raw_row;
362  use_raw_buffer = TRUE;
363  need_rescale = FALSE;
364  } else {
365  source->pub.get_pixel_rows = get_scaled_gray_row;
366  }
367  break;
368 
369  case '6': /* it's a raw-format PPM file */
370  cinfo->input_components = 3;
371  cinfo->in_color_space = JCS_RGB;
372  TRACEMS2(cinfo, 1, JTRC_PPM, w, h);
373  if (maxval > 255) {
374  source->pub.get_pixel_rows = get_word_rgb_row;
375  } else if (maxval == MAXJSAMPLE && SIZEOF(JSAMPLE) == SIZEOF(U_CHAR)) {
376  source->pub.get_pixel_rows = get_raw_row;
377  use_raw_buffer = TRUE;
378  need_rescale = FALSE;
379  } else {
380  source->pub.get_pixel_rows = get_scaled_rgb_row;
381  }
382  break;
383  }
384 
385  /* Allocate space for I/O buffer: 1 or 3 bytes or words/pixel. */
386  if (need_iobuffer) {
387  source->buffer_width = (size_t) w * cinfo->input_components *
388  ((maxval<=255) ? SIZEOF(U_CHAR) : (2*SIZEOF(U_CHAR)));
389  source->iobuffer = (U_CHAR *)
390  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
391  source->buffer_width);
392  }
393 
394  /* Create compressor input buffer. */
395  if (use_raw_buffer) {
396  /* For unscaled raw-input case, we can just map it onto the I/O buffer. */
397  /* Synthesize a JSAMPARRAY pointer structure */
398  /* Cast here implies near->far pointer conversion on PCs */
399  source->pixrow = (JSAMPROW) source->iobuffer;
400  source->pub.buffer = & source->pixrow;
401  source->pub.buffer_height = 1;
402  } else {
403  /* Need to translate anyway, so make a separate sample buffer. */
404  source->pub.buffer = (*cinfo->mem->alloc_sarray)
405  ((j_common_ptr) cinfo, JPOOL_IMAGE,
406  (JDIMENSION) w * cinfo->input_components, (JDIMENSION) 1);
407  source->pub.buffer_height = 1;
408  }
409 
410  /* Compute the rescaling array if required. */
411  if (need_rescale) {
412  INT32 val, half_maxval;
413 
414  /* On 16-bit-int machines we have to be careful of maxval = 65535 */
415  source->rescale = (JSAMPLE *)
416  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
417  (size_t) (((long) maxval + 1L) * SIZEOF(JSAMPLE)));
418  half_maxval = maxval / 2;
419  for (val = 0; val <= (INT32) maxval; val++) {
420  /* The multiplication here must be done in 32 bits to avoid overflow */
421  source->rescale[val] = (JSAMPLE) ((val*MAXJSAMPLE + half_maxval)/maxval);
422  }
423  }
424 }
425 
426 
427 /*
428  * Finish up at the end of the file.
429  */
430 
431 METHODDEF(void)
433 {
434  /* no work */
435 }
436 
437 
438 /*
439  * The module selection routine for PPM format input.
440  */
441 
444 {
445  ppm_source_ptr source;
446 
447  /* Create module interface object */
448  source = (ppm_source_ptr)
449  (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
451  /* Fill in method ptrs, except get_pixel_rows which start_input sets */
452  source->pub.start_input = start_input_ppm;
453  source->pub.finish_input = finish_input_ppm;
454 
455  return (cjpeg_source_ptr) source;
456 }
457 
458 #endif /* PPM_SUPPORTED */
JSAMPLE * rescale
Definition: rdppm.c:77
start_input_ppm(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:296
#define BITS_IN_JSAMPLE
Definition: jmorecfg.h:23
int c
Definition: autoplay.py:16
get_word_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:262
char JSAMPLE
Definition: jmorecfg.h:64
JSAMPLE FAR * JSAMPROW
Definition: jpeglib.h:66
#define FALSE
Definition: OPC_IceHook.h:9
#define ReadOK(file, buffer, len)
Definition: rdppm.c:55
png_voidp ptr
Definition: png.h:2063
struct jpeg_common_struct * j_common_ptr
Definition: jpeglib.h:261
pbm_getc(FILE *infile)
Definition: rdppm.c:84
#define ERREXIT(cinfo, code)
Definition: jerror.h:205
#define TRACEMS2(cinfo, lvl, code, p1, p2)
Definition: jerror.h:259
#define TRUE
Definition: OPC_IceHook.h:13
#define SIZEOF(object)
Definition: jinclude.h:80
#define MAXJSAMPLE
Definition: jmorecfg.h:73
get_scaled_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:179
long INT32
Definition: jmorecfg.h:161
JDIMENSION buffer_height
Definition: cdjpeg.h:37
w
get_raw_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:223
#define JPOOL_IMAGE
Definition: jpeglib.h:749
read_pbm_integer(j_compress_ptr cinfo, FILE *infile)
Definition: rdppm.c:101
struct cjpeg_source_struct pub
Definition: rdppm.c:72
#define LOCAL(type)
Definition: jmorecfg.h:186
JSAMPROW pixrow
Definition: rdppm.c:75
get_text_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:141
int val
Definition: jpeglib.h:956
ppm_source_struct * ppm_source_ptr
Definition: rdppm.c:80
JSAMPARRAY buffer
Definition: cdjpeg.h:36
get_scaled_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:200
get_word_gray_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:238
U_CHAR * iobuffer
Definition: rdppm.c:74
size_t buffer_width
Definition: rdppm.c:76
unsigned char U_CHAR
Definition: rdppm.c:42
#define GLOBAL(type)
Definition: jmorecfg.h:188
FILE * input_file
Definition: cdjpeg.h:34
#define METHODDEF(type)
Definition: jmorecfg.h:184
FILE * infile
Definition: cdjpeg.h:141
jinit_read_ppm(j_compress_ptr cinfo)
Definition: rdppm.c:443
get_text_rgb_row(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:159
unsigned int JDIMENSION
Definition: jmorecfg.h:171
unsigned char U_CHAR
Definition: rdbmp.c:32
finish_input_ppm(j_compress_ptr cinfo, cjpeg_source_ptr sinfo)
Definition: rdppm.c:432
#define UCH(x)
Definition: rdppm.c:43


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