204 lines
5.0 KiB
C
204 lines
5.0 KiB
C
/* hough transform for lines
|
|
*
|
|
* 7/3/14
|
|
* - from hist_find.c
|
|
* 1/2/18
|
|
* - change width to 0 - 180
|
|
*/
|
|
|
|
/*
|
|
|
|
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 <string.h>
|
|
#include <math.h>
|
|
|
|
#include <vips/vips.h>
|
|
|
|
#include "statistic.h"
|
|
#include "hough.h"
|
|
|
|
typedef struct _VipsHoughLine {
|
|
VipsHough parent_instance;
|
|
|
|
/* Size of parameter space.
|
|
*/
|
|
int width;
|
|
int height;
|
|
|
|
/* LUT for this transform.
|
|
*/
|
|
double *sin;
|
|
|
|
} VipsHoughLine;
|
|
|
|
typedef VipsHoughClass VipsHoughLineClass;
|
|
|
|
G_DEFINE_TYPE( VipsHoughLine, vips_hough_line, VIPS_TYPE_HOUGH );
|
|
|
|
static int
|
|
vips_hough_line_build( VipsObject *object )
|
|
{
|
|
VipsHoughLine *hough_line = (VipsHoughLine *) object;
|
|
int width = hough_line->width;
|
|
|
|
int i;
|
|
|
|
if( !(hough_line->sin = VIPS_ARRAY( object, 2 * width, double )) )
|
|
return( -1 );
|
|
|
|
/* Map width to 180 degrees, width * 2 to 360.
|
|
*/
|
|
for( i = 0; i < 2 * width; i++ )
|
|
hough_line->sin[i] = sin( 2 * VIPS_PI * i / (2 * width) );
|
|
|
|
if( VIPS_OBJECT_CLASS( vips_hough_line_parent_class )->build( object ) )
|
|
return( -1 );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static int
|
|
vips_hough_line_init_accumulator( VipsHough *hough, VipsImage *accumulator )
|
|
{
|
|
VipsHoughLine *hough_line = (VipsHoughLine *) hough;
|
|
|
|
vips_image_init_fields( accumulator,
|
|
hough_line->width, hough_line->height, 1,
|
|
VIPS_FORMAT_UINT, VIPS_CODING_NONE,
|
|
VIPS_INTERPRETATION_MATRIX,
|
|
1.0, 1.0 );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/* Cast votes for all lines passing through x, y.
|
|
*/
|
|
static void
|
|
vips_hough_line_vote( VipsHough *hough, VipsImage *accumulator, int x, int y )
|
|
{
|
|
VipsHoughLine *hough_line = (VipsHoughLine *) hough;
|
|
VipsStatistic *statistic = (VipsStatistic *) hough;
|
|
double xd = (double) x / statistic->ready->Xsize;
|
|
double yd = (double) y / statistic->ready->Ysize;
|
|
int width = hough_line->width;
|
|
int height = hough_line->height;
|
|
guint *data = (guint *) accumulator->data;
|
|
|
|
int i;
|
|
|
|
for( i = 0; i < width; i++ ) {
|
|
int i90 = i + width / 2;
|
|
double r = xd * hough_line->sin[i90] + yd * hough_line->sin[i];
|
|
int ri = height * r;
|
|
|
|
if( ri >= 0 &&
|
|
ri < height )
|
|
data[i + ri * width] += 1;
|
|
}
|
|
}
|
|
|
|
static void
|
|
vips_hough_line_class_init( VipsHoughClass *class )
|
|
{
|
|
GObjectClass *gobject_class = (GObjectClass *) class;
|
|
VipsObjectClass *object_class = (VipsObjectClass *) class;
|
|
VipsHoughClass *hclass = (VipsHoughClass *) class;
|
|
|
|
gobject_class->set_property = vips_object_set_property;
|
|
gobject_class->get_property = vips_object_get_property;
|
|
|
|
object_class->nickname = "hough_line";
|
|
object_class->description = _( "find hough line transform" );
|
|
object_class->build = vips_hough_line_build;
|
|
|
|
hclass->init_accumulator = vips_hough_line_init_accumulator;
|
|
hclass->vote = vips_hough_line_vote;
|
|
|
|
VIPS_ARG_INT( class, "width", 110,
|
|
_( "Width" ),
|
|
_( "Horizontal size of parameter space" ),
|
|
VIPS_ARGUMENT_OPTIONAL_INPUT,
|
|
G_STRUCT_OFFSET( VipsHoughLine, width ),
|
|
1, 100000, 256 );
|
|
|
|
VIPS_ARG_INT( class, "height", 111,
|
|
_( "Height" ),
|
|
_( "Vertical size of parameter space" ),
|
|
VIPS_ARGUMENT_OPTIONAL_INPUT,
|
|
G_STRUCT_OFFSET( VipsHoughLine, height ),
|
|
1, 100000, 256 );
|
|
|
|
}
|
|
|
|
static void
|
|
vips_hough_line_init( VipsHoughLine *hough_line )
|
|
{
|
|
hough_line->width = 256;
|
|
hough_line->height = 256;
|
|
}
|
|
|
|
/**
|
|
* vips_hough_line: (method)
|
|
* @in: input image
|
|
* @out: (out): output image
|
|
* @...: %NULL-terminated list of optional named arguments
|
|
*
|
|
* Optional arguments:
|
|
*
|
|
* * @width: horizontal size of parameter space
|
|
* * @height: vertical size of parameter space
|
|
*
|
|
* Find the line Hough transform for @in. @in must have one band. @out has one
|
|
* band, with pixels being the number of votes for that line. The X dimension
|
|
* of @out is the line angle in 0 - 180 degrees, the Y dimension is the
|
|
* distance of the closest part of that line to the origin in the top-left.
|
|
*
|
|
* Use @width @height to set the size of the parameter space image (@out),
|
|
* that is, how accurate the line determination should be.
|
|
*
|
|
* See also: vips_hough_circle().
|
|
*
|
|
* Returns: 0 on success, -1 on error
|
|
*/
|
|
int
|
|
vips_hough_line( VipsImage *in, VipsImage **out, ... )
|
|
{
|
|
va_list ap;
|
|
int result;
|
|
|
|
va_start( ap, out );
|
|
result = vips_call_split( "hough_line", ap, in, out );
|
|
va_end( ap );
|
|
|
|
return( result );
|
|
}
|