libvips/libsrc/conversion/im_msb.c
2008-11-02 22:11:01 +00:00

347 lines
7.7 KiB
C

/* @(#) Convert a signed or unsigned, char or short or int image into unsigned
* @(#) char very quickly, by discarding the lower order bits. Signed values
* @(#) are converted to unsigned by adding 128.
* @(#)
* @(#) int
* @(#) im_msb(
* @(#) IMAGE *in,
* @(#) IMAGE *out
* @(#) );
* @(#)
* @(#) As above, but also discard all but the specified band:
* @(#)
* @(#) int
* @(#) im_msb(
* @(#) IMAGE *in,
* @(#) IMAGE *out,
* @(#) int band
* @(#) );
*
* Copyright: 2006, The Nottingham Trent University
*
* Author: Tom Vajzovic
*
* Written on: 2006-03-13
* 27/9/06
* - removed extra im_free() in im_copy() fallback
* 4/10/06
* - removed warning on uchar fallback: it happens a lot with nip2 and
* isn't very serious
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
/** HEADERS **/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H */
#include <vips/intl.h>
#include <stdlib.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC */
/** MACROS **/
/* BAND FORMAT TESTS */
#define SIZEOF_BAND(band_fmt) ( \
( IM_BANDFMT_UCHAR == (band_fmt) ) ? sizeof(unsigned char) \
: ( IM_BANDFMT_CHAR == (band_fmt) ) ? sizeof(signed char) \
: ( IM_BANDFMT_USHORT == (band_fmt) ) ? sizeof(unsigned short int) \
: ( IM_BANDFMT_SHORT == (band_fmt) ) ? sizeof(signed short int) \
: ( IM_BANDFMT_UINT == (band_fmt) ) ? sizeof(unsigned int) \
: ( IM_BANDFMT_INT == (band_fmt) ) ? sizeof(signed int) \
: ( IM_BANDFMT_FLOAT == (band_fmt) ) ? sizeof(float) \
: ( IM_BANDFMT_DOUBLE == (band_fmt) ) ? sizeof(double) \
: ( IM_BANDFMT_COMPLEX == (band_fmt) ) ? ( 2 * sizeof(float) ) \
: ( 2 * sizeof(double) ) )
#define BANDFMT_SHORT_CHAR(band_fmt) ( \
IM_BANDFMT_SHORT == (band_fmt) \
|| IM_BANDFMT_USHORT == (band_fmt) \
|| IM_BANDFMT_CHAR == (band_fmt) \
|| IM_BANDFMT_UCHAR == (band_fmt) )
#define BANDFMT_ANY_INT(band_fmt) ( \
IM_BANDFMT_INT == (band_fmt) \
|| IM_BANDFMT_UINT == (band_fmt) \
|| BANDFMT_SHORT_CHAR(band_fmt) )
#define BANDFMT_UNSIGNED(band_fmt) ( \
IM_BANDFMT_UINT == (band_fmt) \
|| IM_BANDFMT_USHORT == (band_fmt) \
|| IM_BANDFMT_UCHAR == (band_fmt) )
/* IMAGE TESTS */
#define IM_ANY_INT(im) BANDFMT_ANY_INT((im)-> BandFmt)
#define IM_UNSIGNED(im) BANDFMT_UNSIGNED((im)-> BandFmt)
#define IM_UNCODED(im) ( IM_CODING_NONE == (im)-> Coding )
/** LOCAL FUNCTIONS DECLARATIONS **/
static void byte_select (unsigned char *in, unsigned char *out, int n,
size_t * params);
static void byte_select_flip (unsigned char *in, unsigned char *out, int n,
size_t * params);
static void msb_labq (unsigned char *in, unsigned char *out, int n);
/** EXPORTED FUNCTIONS **/
int
im_msb (IMAGE * in, IMAGE * out)
{
#define FUNCTION_NAME "im_msb"
size_t *params;
im_wrapone_fn func;
#define index (params[0])
#define width (params[1])
#define repeat (params[2])
if (im_piocheck (in, out))
return -1;
/* Stops a used-before-set warning.
*/
params = NULL;
if (IM_UNCODED (in))
{
if (!IM_ANY_INT (in))
{
im_error (FUNCTION_NAME, "%s", _("char, short or int only"));
return -1;
}
params = IM_ARRAY (out, 3, size_t);
if (!params)
return -1;
width = SIZEOF_BAND (in->BandFmt);
#if G_BYTE_ORDER == G_BIG_ENDIAN
index = 0;
#else
index = width - 1;
#endif
repeat = in->Bands;
if (IM_UNSIGNED (in))
func = (im_wrapone_fn) byte_select;
else
func = (im_wrapone_fn) byte_select_flip;
if (1 == width && (im_wrapone_fn) byte_select == func)
{
return im_copy (in, out);
}
}
else if (IM_CODING_LABQ == in->Coding)
func = (im_wrapone_fn) msb_labq;
else
{
im_error (FUNCTION_NAME, "%s", _("unknown coding"));
return -1;
}
if (im_cp_desc (out, in))
return -1;
out->Bbits = sizeof (unsigned char) << 3;
out->BandFmt = IM_BANDFMT_UCHAR;
out->Coding = IM_CODING_NONE;
return im_wrapone (in, out, func, (void *) params, NULL);
#undef index
#undef width
#undef repeat
#undef FUNCTION_NAME
}
int
im_msb_band (IMAGE * in, IMAGE * out, int band)
{
#define FUNCTION_NAME "im_msb_band"
size_t *params;
im_wrapone_fn func;
#define index (params[0])
#define width (params[1])
#define repeat (params[2])
if (band < 0)
{
im_error (FUNCTION_NAME, "%s", _("bad arguments"));
return -1;
}
if (im_piocheck (in, out))
return -1;
params = IM_ARRAY (out, 3, size_t);
if (!params)
return -1;
if (IM_UNCODED (in))
{
if (!IM_ANY_INT (in))
{
im_error (FUNCTION_NAME, "%s", _("char, short or int only"));
return -1;
}
if (band >= in->Bands)
{
im_error (FUNCTION_NAME,
"%s", _("image does not have that many bands"));
return -1;
}
width = SIZEOF_BAND (in->BandFmt);
#if G_BYTE_ORDER == G_BIG_ENDIAN
index = width * band;
#else
index = (width * (band + 1)) - 1;
#endif
width *= in->Bands;
repeat = 1;
if (IM_UNSIGNED (in))
func = (im_wrapone_fn) byte_select;
else
func = (im_wrapone_fn) byte_select_flip;
}
else if (IM_CODING_LABQ == in->Coding)
{
if (band > 2)
{
im_error (FUNCTION_NAME,
"%s", _("image does not have that many bands"));
return -1;
}
width = 4;
repeat = 1;
index = band;
if (band)
func = (im_wrapone_fn) byte_select_flip;
else
func = (im_wrapone_fn) byte_select;
}
else
{
im_error (FUNCTION_NAME, "%s", _("unknown coding"));
return -1;
}
if (im_cp_desc (out, in))
return -1;
out->Bands = 1;
out->Bbits = sizeof (unsigned char) << 3;
out->BandFmt = IM_BANDFMT_UCHAR;
out->Coding = IM_CODING_NONE;
return im_wrapone (in, out, func, (void *) params, NULL);
#undef index
#undef width
#undef repeat
#undef FUNCTION_NAME
}
/** LOCAL FUNCTIONS DEFINITIONS **/
static void
byte_select (unsigned char *in, unsigned char *out, int n, size_t * params)
{
#define index (params[0])
#define width (params[1])
#define repeat (params[2])
unsigned char *stop = out + n * repeat;
for (in += index; out < stop; in += width, ++out)
*out = *in;
#undef index
#undef width
#undef repeat
}
static void
byte_select_flip (unsigned char *in, unsigned char *out, int n,
size_t * params)
{
#define index (params[0])
#define width (params[1])
#define repeat (params[2])
unsigned char *stop = out + n * repeat;
for (in += index; out < stop; in += width, ++out)
*out = 0x80 ^ *in;
#undef index
#undef width
#undef repeat
}
static void
msb_labq (unsigned char *in, unsigned char *out, int n)
{
unsigned char *stop = in + (n << 2);
for (; in < stop; in += 4, out += 3)
{
out[0] = in[0];
out[1] = 0x80 ^ in[1];
out[2] = 0x80 ^ in[2];
}
}