libvips/libsrc/conversion/im_recomb.c

168 lines
4.1 KiB
C

/* @(#) Recombination of bands of image: perform a matrix mult of the form
* @(#)
* @(#) a1 b11 b21 .. bm1 c1
* @(#) a2 b12 b22 .. c2
* @(#) . = . . x .
* @(#) . . .
* @(#)
* @(#) an b1n bmn cm
* @(#)
* @(#) Where A is an n band output image, C is an m band input image and B
* @(#) is an mxn matrix of floats. Can be used with 3x3 matrix to perform
* @(#) simple colour space transforms; 7x30 matrix to shrink 3rd order
* @(#) development of 3 filter system to IM_TYPE_XYZ etc.
* @(#)
* @(#) Output is always float, unless input is double, in which case output
* @(#) is double. Does not work for complex images.
* @(#)
* @(#) Usage:
* @(#) im_recomb( imagein, imageout, mat )
* @(#) IMAGE *imagein, *imageout;
* @(#) DOUBLEMASK *mat;
* @(#)
* @(#) Returns: -1 on error, else 0
* 21/6/95 JC
* - mildly modernised
* 14/3/96 JC
* - better error checks, partial
* - proper rounding behaviour for int types
*/
/*
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
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>
#include <stdio.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
/* Inner loop.
*/
#define LOOP(INTYPE, OUTTYPE) \
{\
INTYPE *p = (INTYPE *) bin;\
OUTTYPE *q = (OUTTYPE *) bout;\
\
for( i = 0; i < width; i++ ) {\
double *m = mat->coeff;\
\
for( v = 0; v < mat->ysize; v++ ) {\
double t = 0.0;\
\
for( u = 0; u < mat->xsize; u++ )\
t += *m++ * p[u];\
\
*q++ = (OUTTYPE) t;\
}\
\
p += mat->xsize;\
}\
}
/* Process a buffer of PELs.
*/
static int
recomb_buf( void *bin, void *bout, int width, IMAGE *in, DOUBLEMASK *mat )
{
int i;
int u, v;
/* Do the processing.
*/
switch( in->BandFmt ) {
case IM_BANDFMT_UCHAR: LOOP( unsigned char, float ); break;
case IM_BANDFMT_CHAR: LOOP( signed char, float ); break;
case IM_BANDFMT_USHORT: LOOP( unsigned short, float ); break;
case IM_BANDFMT_SHORT: LOOP( signed short, float ); break;
case IM_BANDFMT_UINT: LOOP( unsigned int, float ); break;
case IM_BANDFMT_INT: LOOP( signed int, float ); break;
case IM_BANDFMT_FLOAT: LOOP( float, float ); break;
case IM_BANDFMT_DOUBLE: LOOP( double, double ); break;
default:
im_errormsg( "im_recomb: unsupported input type" );
return( -1 );
}
return( 0 );
}
/* Start here.
*/
int
im_recomb( IMAGE *in, IMAGE *out, DOUBLEMASK *mat )
{
DOUBLEMASK *mcpy;
/* Check input image.
*/
if( im_piocheck( in, out ) )
return( -1 );
if( in->Coding != IM_CODING_NONE || im_iscomplex( in ) ) {
im_errormsg( "im_recomb: uncoded non-complex only" );
return( -1 );
}
if( in->Bands != mat->xsize ) {
im_errormsg( "im_recomb: bands in must equal matrix width" );
return( -1 );
}
/* Prepare the output image
*/
if( im_cp_desc( out, in ) )
return( -1 );
out->Bands = mat->ysize;
if( im_isint( in ) ) {
out->Bbits = IM_BBITS_FLOAT;
out->BandFmt = IM_BANDFMT_FLOAT;
}
/* Take a copy of the matrix.
*/
if( !(mcpy = im_dup_dmask( mat, "conv_mask" )) )
return( -1 );
if( im_add_close_callback( out,
(im_callback_fn) im_free_dmask, mcpy, NULL ) ) {
im_free_dmask( mcpy );
return( -1 );
}
/* And process!
*/
if( im_wrapone( in, out, (im_wrapone_fn) recomb_buf, in, mcpy ) )
return( -1 );
return( 0 );
}