libvips/libsrc/colour/im_Lab2LabS.c

93 lines
2.1 KiB
C

/* @(#) im_Lab2LabS: quantise FLOAT Lab image into signed short format
* 12/12/02 JC
* - from im_Lab2LabQ
*/
/*
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 <math.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
void
imb_Lab2LabS( float *in, signed short *out, int n )
{
float *p = in;
signed short *q = out;
int c;
for( c = 0; c < n; c++ ) {
q[0] = p[0] * (32767.0 / 100.0);
q[1] = p[1] * (32768.0 / 128.0);
q[2] = p[2] * (32768.0 / 128.0);
q += 3;
p += 3;
}
}
int
im_Lab2LabS( IMAGE *labim, IMAGE *outim )
{
/* Check for uncoded Lab type
*/
if( labim->Coding != IM_CODING_NONE ) {
im_errormsg( "im_Lab2LabS: uncoded input only" );
return( -1 );
}
if( labim->BandFmt != IM_BANDFMT_FLOAT || labim->Bands != 3 ) {
im_errormsg( "im_Lab2LabS: three-band float input only" );
return( -1 );
}
/* Set up output image.
*/
if( im_cp_desc( outim, labim ) )
return( -1 );
outim->Type = IM_TYPE_LABS;
outim->BandFmt = IM_BANDFMT_SHORT;
outim->Bbits = IM_BBITS_SHORT;
/* Process.
*/
if( im_wrapone( labim, outim,
(im_wrapone_fn) imb_Lab2LabS, NULL, NULL ) )
return( -1 );
return( 0 );
}