99 lines
2.2 KiB
C
99 lines
2.2 KiB
C
/* @(#) transform with log10(1.0 + pow(x, 0.25)) + .5, then scale so max
|
|
* @(#) == 255.
|
|
* @(#)
|
|
* @(#) int im_scaleps(in, out)
|
|
* @(#) IMAGE *in, *out;
|
|
* @(#)
|
|
* @(#) All functions return 0 on success and -1 on error
|
|
* @(#)
|
|
*
|
|
* Copyright: 1990, N. Dessipris.
|
|
*
|
|
* Author: Nicos Dessipris
|
|
* Written on: 02/05/1990
|
|
* Modified on: 14/03/1991
|
|
* 15/6/93 J.Cupitt
|
|
* - externs fixed
|
|
* - includes fixed
|
|
* 13/2/95 JC
|
|
* - ANSIfied
|
|
* - cleaned up
|
|
* 11/7/02 JC
|
|
* - rewritten ... got rid of the stuff for handling -ves, never used
|
|
* (and was broken anyway)
|
|
*/
|
|
|
|
/*
|
|
|
|
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 <stdlib.h>
|
|
#include <math.h>
|
|
|
|
#include <vips/vips.h>
|
|
|
|
#ifdef WITH_DMALLOC
|
|
#include <dmalloc.h>
|
|
#endif /*WITH_DMALLOC*/
|
|
|
|
/* Scale, as noted above.
|
|
*/
|
|
int
|
|
im_scaleps( IMAGE *in, IMAGE *out )
|
|
{
|
|
IMAGE *t[4];
|
|
double mx;
|
|
double scale;
|
|
|
|
if( im_open_local_array( out, t, 4, "im_scaleps-1", "p" ) ||
|
|
im_max( in, &mx ) )
|
|
return( -1 );
|
|
|
|
if( mx <= 0.0 )
|
|
/* Range of zero: just return black.
|
|
*/
|
|
return( im_black( out, in->Xsize, in->Ysize, in->Bands ) );
|
|
|
|
scale = 255.0 / log10( 1.0 + pow( mx, .25 ) );
|
|
|
|
/* Transform!
|
|
*/
|
|
if( im_powtra( in, t[0], 0.25 ) ||
|
|
im_lintra( 1.0, t[0], 1.0, t[1] ) ||
|
|
im_log10tra( t[1], t[2] ) ||
|
|
im_lintra( scale, t[2], 0.0, t[3] ) ||
|
|
im_clip( t[3], out ) )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|
|
|