| /* im_scaleps |
| * |
| * 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) |
| * 1/2/10 |
| * - gtkdoc |
| */ |
| |
| /* |
| |
| 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*/ |
| |
| /** |
| * im_scaleps: |
| * @in: input image |
| * @out: output image |
| * |
| * Scale a power spectrum. Transform with log10(1.0 + pow(x, 0.25)) + .5, |
| * then scale so max == 255. |
| * |
| * See also: im_scale(). |
| * |
| * Returns: 0 on success, -1 on error |
| */ |
| 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_clip2fmt( t[3], out, IM_BANDFMT_UCHAR ) ) |
| return( -1 ); |
| |
| return( 0 ); |
| } |
| |
