File: hist_equal.c

package info (click to toggle)
vips 8.14.1-3%2Bdeb12u2
  • links: PTS
  • area: main
  • in suites: bookworm
  • size: 35,912 kB
  • sloc: ansic: 165,449; cpp: 10,987; python: 4,462; xml: 4,212; sh: 471; perl: 40; makefile: 23
file content (168 lines) | stat: -rw-r--r-- 4,185 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/* Histogram-equalise an image.
 *
 * Copyright: 1991, N. Dessipris.
 *
 * Author: Nicos Dessipris
 * Written on: 27/03/1991
 * Modified on : 
 * 16/6/93 J.Cupitt
 *	- im_ioflag() changed to im_iocheck()
 * 24/5/95 JC
 *	- ANSIfied and tidied up
 * 3/3/01 JC
 *	- more cleanup
 * 23/3/10
 * 	- gtkdoc
 * 12/8/13	
 * 	- redone as a class
 * 19/6/17
 * 	- make output format always == input format, thanks Simon
 */

/*

    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., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301  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 <glib/gi18n-lib.h>

#include <stdio.h>

#include <vips/vips.h>

typedef struct _VipsHistEqual { 
	VipsOperation parent_instance;

	VipsImage *in;
	VipsImage *out;

	/* -1 for all bands, or the band we scan.
	 */
	int which;
} VipsHistEqual;

typedef VipsOperationClass VipsHistEqualClass;

G_DEFINE_TYPE( VipsHistEqual, vips_hist_equal, VIPS_TYPE_OPERATION );

static int
vips_hist_equal_build( VipsObject *object )
{
	VipsHistEqual *equal = (VipsHistEqual *) object; 
	VipsImage **t = (VipsImage **) vips_object_local_array( object, 5 );

	g_object_set( equal, "out", vips_image_new(), NULL ); 

	if( VIPS_OBJECT_CLASS( vips_hist_equal_parent_class )->build( object ) )
		return( -1 );

	/* norm can return a uchar output for a ushort input if the range is
	 * small, so make sure we cast back to the input type again.
	 */
	if( vips_hist_find( equal->in, &t[0], 
			"band", equal->which,
			NULL ) ||
		vips_hist_cum( t[0], &t[1], NULL ) ||
		vips_hist_norm( t[1], &t[2], NULL ) ||
		vips_cast( t[2], &t[3], equal->in->BandFmt, NULL ) ||
		vips_maplut( equal->in, &t[4], t[3], NULL ) ||
		vips_image_write( t[4], equal->out ) )
		return( -1 );

	return( 0 );
}

static void
vips_hist_equal_class_init( VipsHistEqualClass *class )
{
	GObjectClass *gobject_class = G_OBJECT_CLASS( class );
	VipsObjectClass *object_class = (VipsObjectClass *) class;

	gobject_class->set_property = vips_object_set_property;
	gobject_class->get_property = vips_object_get_property;

	object_class->nickname = "hist_equal";
	object_class->description = _( "histogram equalisation" );
	object_class->build = vips_hist_equal_build;

	VIPS_ARG_IMAGE( class, "in", 1, 
		_( "Input" ), 
		_( "Input image" ),
		VIPS_ARGUMENT_REQUIRED_INPUT,
		G_STRUCT_OFFSET( VipsHistEqual, in ) );

	VIPS_ARG_IMAGE( class, "out", 2, 
		_( "Output" ), 
		_( "Output image" ),
		VIPS_ARGUMENT_REQUIRED_OUTPUT, 
		G_STRUCT_OFFSET( VipsHistEqual, out ) );

	VIPS_ARG_INT( class, "band", 110, 
		_( "Band" ), 
		_( "Equalise with this band" ),
		VIPS_ARGUMENT_OPTIONAL_INPUT, 
		G_STRUCT_OFFSET( VipsHistEqual, which ),
		-1, 100000, -1 );
}

static void
vips_hist_equal_init( VipsHistEqual *equal )
{
	equal->which = -1;
}

/**
 * vips_hist_equal: (method)
 * @in: input image
 * @out: (out): output image
 * @...: %NULL-terminated list of optional named arguments
 *
 * Optional arguments:
 *
 * * @band: band to equalise
 *
 * Histogram-equalise @in. Equalise using band @bandno, or if @bandno is -1,
 * equalise bands independently. The output format is always the same as the
 * input format. 
 *
 * See also: 
 *
 * Returns: 0 on success, -1 on error
 */
int 
vips_hist_equal( VipsImage *in, VipsImage **out, ... )
{
	va_list ap;
	int result;

	va_start( ap, out );
	result = vips_call_split( "hist_equal", ap, in, out );
	va_end( ap );

	return( result );
}