1 /*
2 * Brute force align the bands of an image.
3 *
4 * Copyright: Nottingham Trent University
5 * Author: Tom Vajzovic
6 * Written on: 2008-02-04
7 */
8
9 /*
10
11 This file is part of VIPS.
12
13 VIPS is free software; you can redistribute it and/or modify
14 it under the terms of the GNU Lesser General Public License as published by
15 the Free Software Foundation; either version 2 of the License, or
16 (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful,
19 but WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 GNU Lesser General Public License for more details.
22
23 You should have received a copy of the GNU Lesser General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
26 02110-1301 USA
27
28 */
29
30 /*
31
32 These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
33
34 */
35
36 #ifdef HAVE_CONFIG_H
37 #include <config.h>
38 #endif /*HAVE_CONFIG_H*/
39
40 #include <vips/intl.h>
41 #include <vips/vips.h>
42 #include <vips/vips7compat.h>
43
44 /**
45 * im_align_bands:
46 * @in: image to align
47 * @out: output image
48 *
49 * This operation uses im_phasecor_fft() to find an integer displacement to
50 * align all image bands band 0. It is very slow and not very accurate.
51 *
52 * Use im_estpar() in preference: it's fast and accurate.
53 *
54 * See also: im_global_balancef(), im_remosaic().
55 *
56 * Returns: 0 on success, -1 on error
57 */
im_align_bands(IMAGE * in,IMAGE * out)58 int im_align_bands( IMAGE *in, IMAGE *out ){
59 #define FUNCTION_NAME "im_align_bands"
60 if( im_piocheck( in, out ))
61 return -1;
62
63 if( 1 == in-> Bands )
64 return im_copy( in, out );
65 {
66 IMAGE **bands= IM_ARRAY( out, 2 * in-> Bands, IMAGE* );
67 IMAGE **wrapped_bands= bands + in-> Bands;
68 double x= 0.0;
69 double y= 0.0;
70 int i;
71
72 if( ! bands || im_open_local_array( out, bands, in-> Bands, FUNCTION_NAME ": bands", "p" )
73 || im_open_local_array( out, wrapped_bands + 1, in-> Bands - 1, FUNCTION_NAME ": wrapped_bands", "p" ))
74 return -1;
75
76 for( i= 0; i < in-> Bands; ++i )
77 if( im_extract_band( in, bands[i], i ))
78 return -1;
79
80 wrapped_bands[ 0 ]= bands[0];
81
82 for( i= 1; i < in-> Bands; ++i ){
83 IMAGE *temp= im_open( FUNCTION_NAME ": temp", "t" );
84 double this_x, this_y, val;
85
86 if( ! temp || im_phasecor_fft( bands[i-1], bands[i], temp )
87 || im_maxpos_avg( temp, & this_x, & this_y, & val ) || im_close( temp ))
88 return -1;
89
90 x+= this_x;
91 y+= this_y;
92
93 if( im_wrap( bands[i], wrapped_bands[i], (int) x, (int) y ))
94 return -1;
95 }
96 return im_gbandjoin( wrapped_bands, out, in-> Bands );
97 }
98 #undef FUNCTION_NAME
99 }
100