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#define _BSD_SOURCE /* Make sure string.h containst strcasecmp() */
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <limits.h>
#include "pm.h"
#include "global_variables.h"
#include "util.h"
#include "decode.h"
#include "bayer.h"
#include "ljpeg.h"
/*
Not a full implementation of Lossless JPEG, just
enough to decode Canon, Kodak and Adobe DNG images.
*/
int
ljpeg_start(FILE * const ifP,
struct jhead * const jhP) {
int i, tag;
unsigned char data[256], *dp;
init_decoder();
for (i=0; i < 4; i++)
jhP->huff[i] = free_decode;
fread (data, 2, 1, ifP);
if (data[0] != 0xff || data[1] != 0xd8) return 0;
do {
unsigned int len;
fread (data, 2, 2, ifP);
tag = data[0] << 8 | data[1];
len = data[2] << 8 | data[3];
if (len < 2)
pm_error("Length field is %u; must be at least 2", len);
else {
unsigned int const dataLen = len - 2;
if (tag <= 0xff00 || dataLen > 255) return 0;
fread (data, 1, dataLen, ifP);
switch (tag) {
case 0xffc3:
jhP->bits = data[0];
jhP->high = data[1] << 8 | data[2];
jhP->wide = data[3] << 8 | data[4];
jhP->clrs = data[5];
break;
case 0xffc4:
for (dp = data; dp < data + dataLen && *dp < 4; ) {
jhP->huff[*dp] = free_decode;
dp = make_decoder (++dp, 0);
}
}
}
} while (tag != 0xffda);
jhP->row = calloc (jhP->wide*jhP->clrs, 2);
if (jhP->row == NULL)
pm_error("Out of memory in ljpeg_start()");
for (i=0; i < 4; i++)
jhP->vpred[i] = 1 << (jhP->bits-1);
zero_after_ff = 1;
getbits(ifP, -1);
return 1;
}
int
ljpeg_diff(FILE * const ifP,
struct decode * const dindexHeadP) {
int len;
int diff;
struct decode * dindexP;
for (dindexP = dindexHeadP; dindexP->branch[0]; )
dindexP = dindexP->branch[getbits(ifP, 1)];
diff = getbits(ifP, len = dindexP->leaf);
if ((diff & (1 << (len-1))) == 0)
diff -= (1 << len) - 1;
return diff;
}
void
ljpeg_row(FILE * const ifP,
struct jhead * const jhP) {
int col, c, diff;
unsigned short *outp=jhP->row;
for (col=0; col < jhP->wide; col++)
for (c=0; c < jhP->clrs; c++) {
diff = ljpeg_diff(ifP, jhP->huff[c]);
*outp = col ? outp[-jhP->clrs]+diff : (jhP->vpred[c] += diff);
outp++;
}
}
void
lossless_jpeg_load_raw(Image const image) {
int jwide, jrow, jcol, val, jidx, i, row, col;
struct jhead jh;
int min=INT_MAX;
if (!ljpeg_start (ifp, &jh)) return;
jwide = jh.wide * jh.clrs;
for (jrow=0; jrow < jh.high; jrow++) {
ljpeg_row (ifp, &jh);
for (jcol=0; jcol < jwide; jcol++) {
val = curve[jh.row[jcol]];
jidx = jrow*jwide + jcol;
if (raw_width == 5108) {
i = jidx / (1680*jh.high);
if (i < 2) {
row = jidx / 1680 % jh.high;
col = jidx % 1680 + i*1680;
} else {
jidx -= 2*1680*jh.high;
row = jidx / 1748;
col = jidx % 1748 + 2*1680;
}
} else if (raw_width == 3516) {
row = jidx / 1758;
col = jidx % 1758;
if (row >= raw_height) {
row -= raw_height;
col += 1758;
}
} else {
row = jidx / raw_width;
col = jidx % raw_width;
}
if ((unsigned) (row-top_margin) >= height) continue;
if ((unsigned) (col-left_margin) < width) {
BAYER(row-top_margin,col-left_margin) = val;
if (min > val) min = val;
} else
black += val;
}
}
free (jh.row);
if (raw_width > width)
black /= (raw_width - width) * height;
if (!strcasecmp(make,"KODAK"))
black = min;
}
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