libvips/libsrc/colour/im_LabS2Lab.c

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2007-08-29 18:23:50 +02:00
/* @(#) im_LabS2Lab() - convert short LAB format to Lab.
* @(#)
* @(#) int im_LabS2Lab( IMAGE *in, IMAGE *out )
* @(#)
* @(#)
*
* 12/12/02 JC
* - adapted from im_LabS2LabQ()
*/
/*
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*/
/* Convert n pels from signed short to Lab.
*/
void
imb_LabS2Lab( signed short *in, float *out, int n )
{
signed short *p = in;
float *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);
p += 3;
q += 3;
}
}
int
im_LabS2Lab( IMAGE *in, IMAGE *out )
{
/* Check type.
*/
if( in->Coding != IM_CODING_NONE ) {
im_errormsg( "im_LabS2Lab: not an uncoded image" );
return( -1 );
}
if( in->BandFmt != IM_BANDFMT_SHORT || in->Bands != 3 ) {
im_errormsg( "im_LabS2Lab: not a 3-band signed short image" );
return( -1 );
}
/* Set up output image
*/
if( im_cp_desc( out, in ) )
return( -1 );
out->Type = IM_TYPE_LAB;
out->BandFmt = IM_BANDFMT_FLOAT;
out->Bbits = IM_BBITS_FLOAT;
if( im_wrapone( in, out,
(im_wrapone_fn) imb_LabS2Lab, NULL, NULL ) )
return( -1 );
return( 0 );
}