libvips/libvips/histogram/hist_cum.c

183 lines
4.5 KiB
C

/* histogram cumulativisation
*
* Author: N. Dessipris
* Written on: 02/08/1990
* 24/5/95 JC
* - tidied up and ANSIfied
* 20/7/95 JC
* - smartened up again
* - now works for hists >256 elements
* 3/3/01 JC
* - broken into cum and norm ... helps im_histspec()
* - better behaviour for >8 bit hists
* 31/10/05 JC
* - was broken for vertical histograms, gah
* - neater im_histnorm()
* 23/7/07
* - eek, off by 1 for more than 1 band hists
* 12/5/08
* - histcum works for signed hists now as well
* 24/3/10
* - gtkdoc
* - small cleanups
* 12/8/13
* - redone im_histcum() as a class, vips_hist_cum()
*/
/*
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 <vips/intl.h>
#include <stdio.h>
#include <vips/vips.h>
#include "phistogram.h"
#include "hist_unary.h"
typedef VipsHistUnary VipsHistCum;
typedef VipsHistUnaryClass VipsHistCumClass;
G_DEFINE_TYPE( VipsHistCum, vips_hist_cum, VIPS_TYPE_HIST_UNARY );
#define ACCUMULATE( ITYPE, OTYPE ) { \
for( b = 0; b < nb; b++ ) { \
ITYPE *p = (ITYPE *) in[0]; \
OTYPE *q = (OTYPE *) out; \
OTYPE total; \
\
total = 0; \
for( x = b; x < mx; x += nb ) { \
total += p[x]; \
q[x] = total; \
} \
} \
}
static void
vips_hist_cum_process( VipsHistogram *histogram,
VipsPel *out, VipsPel **in, int width )
{
const int bands = vips_image_get_bands( histogram->ready[0] );
const int nb =
vips_band_format_iscomplex( histogram->ready[0]->BandFmt ) ?
bands * 2 : bands;
int mx = width * nb;
int x, b;
switch( vips_image_get_format( histogram->ready[0] ) ) {
case VIPS_FORMAT_CHAR:
ACCUMULATE( signed char, signed int ); break;
case VIPS_FORMAT_UCHAR:
ACCUMULATE( unsigned char, unsigned int ); break;
case VIPS_FORMAT_SHORT:
ACCUMULATE( signed short, signed int ); break;
case VIPS_FORMAT_USHORT:
ACCUMULATE( unsigned short, unsigned int ); break;
case VIPS_FORMAT_INT:
ACCUMULATE( signed int, signed int ); break;
case VIPS_FORMAT_UINT:
ACCUMULATE( unsigned int, unsigned int ); break;
case VIPS_FORMAT_FLOAT:
case VIPS_FORMAT_COMPLEX:
ACCUMULATE( float, float ); break;
case VIPS_FORMAT_DOUBLE:
case VIPS_FORMAT_DPCOMPLEX:
ACCUMULATE( double, double ); break;
default:
g_assert_not_reached();
}
}
/* Save a bit of typing.
*/
#define UC VIPS_FORMAT_UCHAR
#define C VIPS_FORMAT_CHAR
#define US VIPS_FORMAT_USHORT
#define S VIPS_FORMAT_SHORT
#define UI VIPS_FORMAT_UINT
#define I VIPS_FORMAT_INT
#define F VIPS_FORMAT_FLOAT
#define X VIPS_FORMAT_COMPLEX
#define D VIPS_FORMAT_DOUBLE
#define DX VIPS_FORMAT_DPCOMPLEX
static const VipsBandFormat vips_hist_cum_format_table[10] = {
/* UC C US S UI I F X D DX */
UI, I, UI, I, UI, I, F, F, D, D
};
static void
vips_hist_cum_class_init( VipsHistCumClass *class )
{
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsHistogramClass *hclass = VIPS_HISTOGRAM_CLASS( class );
object_class->nickname = "hist_cum";
object_class->description = _( "form cumulative histogram" );
hclass->format_table = vips_hist_cum_format_table;
hclass->process = vips_hist_cum_process;
}
static void
vips_hist_cum_init( VipsHistCum *hist_cum )
{
}
/**
* vips_hist_cum: (method)
* @in: input image
* @out: (out): output image
* @...: %NULL-terminated list of optional named arguments
*
* Form cumulative histogram.
*
* See also: vips_hist_norm().
*
* Returns: 0 on success, -1 on error
*/
int
vips_hist_cum( VipsImage *in, VipsImage **out, ... )
{
va_list ap;
int result;
va_start( ap, out );
result = vips_call_split( "hist_cum", ap, in, out );
va_end( ap );
return( result );
}