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/* wbmptopbm.c - convert a wbmp file to a portable bitmap
This is derived for Netpbm from the pbmwbmp package from
<http://www.looplab.com/wap/tools> on 2000.06.06.
The specifications for the wbmp format are part of the Wireless
Application Environment specification at
<http://www.wapforum.org/what/technical.htm>.
** Copyright (C) 1999 Terje Sannum <terje@looplab.com>.
**
** 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 "pbm.h"
static int
readc(FILE *f) {
int c = fgetc(f);
if(c == EOF) pm_error("EOF / read error");
return c;
}
static int
readint(FILE *f) {
int c=0, pos=0, sum=0;
do {
c = readc(f);
sum = (sum << 7*pos++) | (c & 0x7f);
} while(c & 0x80);
return sum;
}
static void
readheader(int h, FILE *f) {
int c,i;
switch(h & 0x60) {
case 0x00:
/* Type 00: read multi-byte bitfield */
do c=readc(f); while(c & 0x80);
break;
case 0x60:
/* Type 11: read name/value pair */
for(i=0; i < ((h & 0x70) >> 4) + (h & 0x0f); i++) c=readc(f);
break;
}
}
static bit **
readwbmp(FILE *f, int *cols, int *rows) {
int i,j,k,row,c;
bit **image;
/* Type */
c = readint(f);
if(c != 0) pm_error("Unrecognized WBMP type");
/* Headers */
c = readc(f); /* FixHeaderField */
while(c & 0x80) { /* ExtHeaderFields */
c = readc(f);
readheader(c, f);
}
/* Geometry */
*cols = readint(f);
*rows = readint(f);
image = pbm_allocarray(*cols, *rows);
/* read image */
row = *cols/8;
if(*cols%8) row +=1;
for(i=0; i<*rows; i++) {
for(j=0; j<row; j++) {
c=readc(f);
for(k=0; k<8 && j*8+k<*cols; k++) {
image[i][j*8+k] = c & (0x80 >> k) ? PBM_WHITE : PBM_BLACK;
}
}
}
return image;
}
int
main(int argc, char *argv[]) {
FILE *f;
bit **image;
int rows, cols;
pbm_init(&argc, argv);
if(argc > 2) {
fprintf(stderr, "Copyright (C) 1999 Terje Sannum <terje@looplab.com>\n");
pm_usage("[wbmpfile]");
}
f = argc == 2 ? pm_openr(argv[1]) : stdin;
image = readwbmp(f, &cols, &rows);
pm_close(f);
pbm_writepbm(stdout, image, cols, rows, 0);
pm_close(stdout);
return 0;
}
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