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/* psidtopgm.c - convert PostScript "image" data into a portable graymap
**
** Copyright (C) 1989 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.
*/
#include "pgm.h"
static int
gethexit(FILE * const ifp) {
for ( ; ; ) {
int const i = getc(ifp);
if (i == EOF)
pm_error("EOF / read error");
else {
char const c = (char) i;
if (c >= '0' && c <= '9')
return c - '0';
else if (c >= 'A' && c <= 'F')
return c - 'A' + 10;
else if (c >= 'a' && c <= 'f')
return c - 'a' + 10;
/* Else ignore - whitespace. */
}
}
}
int
main(int argc,
char ** argv) {
FILE * ifP;
gray * grayrow;
int argn, row;
gray maxval;
int rows, cols, bitspersample;
pgm_init(&argc, argv);
argn = 1;
if (argn + 3 > argc)
pm_error("Too few arguments");
cols = atoi(argv[argn++]);
rows = atoi(argv[argn++]);
bitspersample = atoi(argv[argn++]);
if (cols <= 0)
pm_error("Columns must be positive. You specified %d",
cols);
if (rows <= 0)
pm_error("Rows must be positive. You specified %d",
rows);
if (bitspersample <= 0)
pm_error("Bits per sample must be positive. You specified %d",
bitspersample);
if (argn < argc)
ifP = pm_openr(argv[argn++]);
else
ifP = stdin;
if (argn != argc)
pm_error("Too many arguments");
maxval = pm_bitstomaxval(bitspersample);
if (maxval > PGM_OVERALLMAXVAL)
pm_error("bits/sample (%d) is too large.", bitspersample);
pgm_writepgminit(stdout, cols, rows, maxval, 0);
grayrow = pgm_allocrow((cols + 7) / 8 * 8);
for (row = 0; row < rows; ++row) {
unsigned int col;
for (col = 0; col < cols; ) {
int val;
val = gethexit(ifP) << 4;
val += gethexit(ifP);
switch (bitspersample) {
case 1:
grayrow[col++] = val >> 7;
grayrow[col++] = ( val >> 6 ) & 0x1;
grayrow[col++] = ( val >> 5 ) & 0x1;
grayrow[col++] = ( val >> 4 ) & 0x1;
grayrow[col++] = ( val >> 3 ) & 0x1;
grayrow[col++] = ( val >> 2 ) & 0x1;
grayrow[col++] = ( val >> 1 ) & 0x1;
grayrow[col++] = val & 0x1;
break;
case 2:
grayrow[col++] = val >> 6;
grayrow[col++] = ( val >> 4 ) & 0x3;
grayrow[col++] = ( val >> 2 ) & 0x3;
grayrow[col++] = val & 0x3;
break;
case 4:
grayrow[col++] = val >> 4;
grayrow[col++] = val & 0xf;
break;
case 8:
grayrow[col++] = val;
break;
default:
pm_error("This program does not know how to interpret a"
"%d bitspersample image", bitspersample );
}
}
pgm_writepgmrow(stdout, grayrow, cols, (gray) maxval, 0);
}
pgm_freerow(grayrow);
pm_close(ifP);
pm_close(stdout);
return 0;
}
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