mirror of
https://github.com/opencv/opencv.git
synced 2024-12-16 02:19:12 +08:00
208 lines
6.9 KiB
C
208 lines
6.9 KiB
C
/* $Id: tif_thunder.c,v 1.12 2011-04-02 20:54:09 bfriesen Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1988-1997 Sam Leffler
|
|
* Copyright (c) 1991-1997 Silicon Graphics, Inc.
|
|
*
|
|
* Permission to use, copy, modify, distribute, and sell this software and
|
|
* its documentation for any purpose is hereby granted without fee, provided
|
|
* that (i) the above copyright notices and this permission notice appear in
|
|
* all copies of the software and related documentation, and (ii) the names of
|
|
* Sam Leffler and Silicon Graphics may not be used in any advertising or
|
|
* publicity relating to the software without the specific, prior written
|
|
* permission of Sam Leffler and Silicon Graphics.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
|
|
* EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
|
|
* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
|
|
*
|
|
* IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
|
|
* ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
|
|
* OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
|
|
* WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
|
|
* LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
|
|
* OF THIS SOFTWARE.
|
|
*/
|
|
|
|
#include "tiffiop.h"
|
|
#include <assert.h>
|
|
#ifdef THUNDER_SUPPORT
|
|
/*
|
|
* TIFF Library.
|
|
*
|
|
* ThunderScan 4-bit Compression Algorithm Support
|
|
*/
|
|
|
|
/*
|
|
* ThunderScan uses an encoding scheme designed for
|
|
* 4-bit pixel values. Data is encoded in bytes, with
|
|
* each byte split into a 2-bit code word and a 6-bit
|
|
* data value. The encoding gives raw data, runs of
|
|
* pixels, or pixel values encoded as a delta from the
|
|
* previous pixel value. For the latter, either 2-bit
|
|
* or 3-bit delta values are used, with the deltas packed
|
|
* into a single byte.
|
|
*/
|
|
#define THUNDER_DATA 0x3f /* mask for 6-bit data */
|
|
#define THUNDER_CODE 0xc0 /* mask for 2-bit code word */
|
|
/* code values */
|
|
#define THUNDER_RUN 0x00 /* run of pixels w/ encoded count */
|
|
#define THUNDER_2BITDELTAS 0x40 /* 3 pixels w/ encoded 2-bit deltas */
|
|
#define DELTA2_SKIP 2 /* skip code for 2-bit deltas */
|
|
#define THUNDER_3BITDELTAS 0x80 /* 2 pixels w/ encoded 3-bit deltas */
|
|
#define DELTA3_SKIP 4 /* skip code for 3-bit deltas */
|
|
#define THUNDER_RAW 0xc0 /* raw data encoded */
|
|
|
|
static const int twobitdeltas[4] = { 0, 1, 0, -1 };
|
|
static const int threebitdeltas[8] = { 0, 1, 2, 3, 0, -3, -2, -1 };
|
|
|
|
#define SETPIXEL(op, v) { \
|
|
lastpixel = (v) & 0xf; \
|
|
if ( npixels < maxpixels ) \
|
|
{ \
|
|
if (npixels++ & 1) \
|
|
*op++ |= lastpixel; \
|
|
else \
|
|
op[0] = (uint8) (lastpixel << 4); \
|
|
} \
|
|
}
|
|
|
|
static int
|
|
ThunderSetupDecode(TIFF* tif)
|
|
{
|
|
static const char module[] = "ThunderSetupDecode";
|
|
|
|
if( tif->tif_dir.td_bitspersample != 4 )
|
|
{
|
|
TIFFErrorExt(tif->tif_clientdata, module,
|
|
"Wrong bitspersample value (%d), Thunder decoder only supports 4bits per sample.",
|
|
(int) tif->tif_dir.td_bitspersample );
|
|
return 0;
|
|
}
|
|
|
|
|
|
return (1);
|
|
}
|
|
|
|
static int
|
|
ThunderDecode(TIFF* tif, uint8* op, tmsize_t maxpixels)
|
|
{
|
|
static const char module[] = "ThunderDecode";
|
|
register unsigned char *bp;
|
|
register tmsize_t cc;
|
|
unsigned int lastpixel;
|
|
tmsize_t npixels;
|
|
|
|
bp = (unsigned char *)tif->tif_rawcp;
|
|
cc = tif->tif_rawcc;
|
|
lastpixel = 0;
|
|
npixels = 0;
|
|
while (cc > 0 && npixels < maxpixels) {
|
|
int n, delta;
|
|
|
|
n = *bp++, cc--;
|
|
switch (n & THUNDER_CODE) {
|
|
case THUNDER_RUN: /* pixel run */
|
|
/*
|
|
* Replicate the last pixel n times,
|
|
* where n is the lower-order 6 bits.
|
|
*/
|
|
if (npixels & 1) {
|
|
op[0] |= lastpixel;
|
|
lastpixel = *op++; npixels++; n--;
|
|
} else
|
|
lastpixel |= lastpixel << 4;
|
|
npixels += n;
|
|
if (npixels < maxpixels) {
|
|
for (; n > 0; n -= 2)
|
|
*op++ = (uint8) lastpixel;
|
|
}
|
|
if (n == -1)
|
|
*--op &= 0xf0;
|
|
lastpixel &= 0xf;
|
|
break;
|
|
case THUNDER_2BITDELTAS: /* 2-bit deltas */
|
|
if ((delta = ((n >> 4) & 3)) != DELTA2_SKIP)
|
|
SETPIXEL(op, lastpixel + twobitdeltas[delta]);
|
|
if ((delta = ((n >> 2) & 3)) != DELTA2_SKIP)
|
|
SETPIXEL(op, lastpixel + twobitdeltas[delta]);
|
|
if ((delta = (n & 3)) != DELTA2_SKIP)
|
|
SETPIXEL(op, lastpixel + twobitdeltas[delta]);
|
|
break;
|
|
case THUNDER_3BITDELTAS: /* 3-bit deltas */
|
|
if ((delta = ((n >> 3) & 7)) != DELTA3_SKIP)
|
|
SETPIXEL(op, lastpixel + threebitdeltas[delta]);
|
|
if ((delta = (n & 7)) != DELTA3_SKIP)
|
|
SETPIXEL(op, lastpixel + threebitdeltas[delta]);
|
|
break;
|
|
case THUNDER_RAW: /* raw data */
|
|
SETPIXEL(op, n);
|
|
break;
|
|
}
|
|
}
|
|
tif->tif_rawcp = (uint8*) bp;
|
|
tif->tif_rawcc = cc;
|
|
if (npixels != maxpixels) {
|
|
#if defined(__WIN32__) && (defined(_MSC_VER) || defined(__MINGW32__))
|
|
TIFFErrorExt(tif->tif_clientdata, module,
|
|
"%s data at scanline %lu (%I64u != %I64u)",
|
|
npixels < maxpixels ? "Not enough" : "Too much",
|
|
(unsigned long) tif->tif_row,
|
|
(unsigned __int64) npixels,
|
|
(unsigned __int64) maxpixels);
|
|
#else
|
|
TIFFErrorExt(tif->tif_clientdata, module,
|
|
"%s data at scanline %lu (%llu != %llu)",
|
|
npixels < maxpixels ? "Not enough" : "Too much",
|
|
(unsigned long) tif->tif_row,
|
|
(unsigned long long) npixels,
|
|
(unsigned long long) maxpixels);
|
|
#endif
|
|
return (0);
|
|
}
|
|
|
|
return (1);
|
|
}
|
|
|
|
static int
|
|
ThunderDecodeRow(TIFF* tif, uint8* buf, tmsize_t occ, uint16 s)
|
|
{
|
|
static const char module[] = "ThunderDecodeRow";
|
|
uint8* row = buf;
|
|
|
|
(void) s;
|
|
if (occ % tif->tif_scanlinesize)
|
|
{
|
|
TIFFErrorExt(tif->tif_clientdata, module, "Fractional scanlines cannot be read");
|
|
return (0);
|
|
}
|
|
while (occ > 0) {
|
|
if (!ThunderDecode(tif, row, tif->tif_dir.td_imagewidth))
|
|
return (0);
|
|
occ -= tif->tif_scanlinesize;
|
|
row += tif->tif_scanlinesize;
|
|
}
|
|
return (1);
|
|
}
|
|
|
|
int
|
|
TIFFInitThunderScan(TIFF* tif, int scheme)
|
|
{
|
|
(void) scheme;
|
|
|
|
tif->tif_setupdecode = ThunderSetupDecode;
|
|
tif->tif_decoderow = ThunderDecodeRow;
|
|
tif->tif_decodestrip = ThunderDecodeRow;
|
|
return (1);
|
|
}
|
|
#endif /* THUNDER_SUPPORT */
|
|
|
|
/* vim: set ts=8 sts=8 sw=8 noet: */
|
|
/*
|
|
* Local Variables:
|
|
* mode: c
|
|
* c-basic-offset: 8
|
|
* fill-column: 78
|
|
* End:
|
|
*/
|