159 lines
3.8 KiB
C
159 lines
3.8 KiB
C
/* @(#) im_Lab2LabQ: quantise FLOAT Lab image into 10 11 11 format
|
|
* 4 bytes per pel: l a b lsbs
|
|
* this is an image wrapper which calls line-wise packing
|
|
* Copyright K.Martinez 3/5/93
|
|
* Modified:
|
|
* 7/6/93 JC
|
|
* - adapted for partial v2
|
|
* 5/5/94 JC
|
|
* - some nint->+0.5, for speed and to ease portability
|
|
* - other nint->rint
|
|
* - now inclues <math.h>!
|
|
* 15/11/94 JC
|
|
* - all nint(), rint() removed for speed
|
|
* - now -128 rather than -127 for a, b
|
|
* - checks input type properly
|
|
* 16/11/94 JC
|
|
* - uses new im_wrap_oneonebuf()
|
|
* 22/5/95 JC
|
|
* - changed L to scale by 10.24, not 10.23
|
|
* 11/7/95 JC
|
|
* - now uses IM_RINT() for rounding
|
|
* 4/9/97 JC
|
|
* - L* = 100.0 now allowed
|
|
* 5/11/00 JC
|
|
* - go int earlier for speed up
|
|
* 20/6/02 JC
|
|
* - oops, were not clipping a/b range correctly
|
|
*/
|
|
|
|
/*
|
|
|
|
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*/
|
|
|
|
/* @(#) convert float Lab to packed Lab32 format 10 11 11 bits
|
|
* works only on buffers, not IMAGEs
|
|
* Copyright 1993 K.Martinez
|
|
* Modified: 3/5/93, 16/6/93
|
|
*/
|
|
void
|
|
imb_Lab2LabQ( float *inp, unsigned char *outbuf, int n )
|
|
{
|
|
float *f, fval;
|
|
int lsbs, intv;
|
|
int Xc;
|
|
unsigned char *out;
|
|
|
|
out = outbuf;
|
|
f = inp;
|
|
for( Xc = 0; Xc < n; Xc++) {
|
|
/* Scale L up to 10 bits. Add 0.5 rather than call IM_RINT for
|
|
* speed. This will not round negatives correctly! But this
|
|
* does not matter, since L is >0. L*=100.0 -> 1023.
|
|
*/
|
|
intv = 10.23 * f[0] + 0.5; /* scale L up to 10 bits */
|
|
if( intv > 1023 )
|
|
intv = 1023;
|
|
if( intv < 0 )
|
|
intv = 0;
|
|
lsbs = (intv & 0x3) << 6; /* 00000011 -> 11000000 */
|
|
out[0] = (intv >> 2); /* drop bot 2 bits and store */
|
|
|
|
fval = 8.0 * f[1]; /* do a */
|
|
intv = IM_RINT( fval );
|
|
if( intv > 1023 )
|
|
intv = 1023;
|
|
else if( intv < -1024 )
|
|
intv = -1024;
|
|
|
|
/* Break into bits.
|
|
*/
|
|
lsbs |= (intv & 0x7) << 3; /* 00000111 -> 00111000 */
|
|
out[1] = (intv >> 3); /* drop bot 3 bits & store */
|
|
|
|
fval = 8.0 * f[2]; /* do b */
|
|
intv = IM_RINT( fval );
|
|
if( intv > 1023 )
|
|
intv = 1023;
|
|
else if( intv < -1024 )
|
|
intv = -1024;
|
|
|
|
lsbs |= (intv & 0x7);
|
|
out[2] = (intv >> 3);
|
|
|
|
out[3] = lsbs; /* store lsb band */
|
|
|
|
f += 3;
|
|
out += 4;
|
|
}
|
|
}
|
|
|
|
int
|
|
im_Lab2LabQ( IMAGE *labim, IMAGE *outim )
|
|
{
|
|
/* Check for uncoded Lab type
|
|
*/
|
|
if( labim->Coding != IM_CODING_NONE ) {
|
|
im_errormsg( "im_Lab2LabQ: uncoded input only" );
|
|
return( -1 );
|
|
}
|
|
if( labim->BandFmt != IM_BANDFMT_FLOAT || labim->Bands != 3 ) {
|
|
im_errormsg( "im_Lab2LabQ: three-band float input only" );
|
|
return( -1 );
|
|
}
|
|
|
|
/* Set up output image.
|
|
*/
|
|
if( im_cp_desc( outim, labim ) )
|
|
return( -1 );
|
|
outim->Bands = 4;
|
|
outim->Type = IM_TYPE_LAB;
|
|
outim->BandFmt = IM_BANDFMT_UCHAR;
|
|
outim->Bbits = 8;
|
|
outim->Coding = IM_CODING_LABQ;
|
|
|
|
/* Process.
|
|
*/
|
|
if( im_wrapone( labim, outim,
|
|
(im_wrapone_fn) imb_Lab2LabQ, NULL, NULL ) )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|