149 lines
3.6 KiB
C
149 lines
3.6 KiB
C
/* @(#) im_complass: Optimised convolution for line detection
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* @(#) Uses the entered mask and 7 rotated versions of it (each by 45 degrees)
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* @(#)
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* @(#) Usage
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* @(#) int im_compass( in, out, m )
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* @(#) IMAGE *in, *out;
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* @(#) INTMASK *m;
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* @(#)
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* @(#) Returns 0 on sucess and -1 on error
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* @(#)
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* @(#) Returns an int pointer to valid offsets for rotating a square mask
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* @(#) of odd size by 45 degrees.
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* @(#)
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* @(#) Usage
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* @(#) int *im_offsets45( size )
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* @(#) int size;
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* @(#)
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* @(#) Returns an int pointer to valid offsets on sucess and -1 on error
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* @(#)
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*
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* Author: N. Dessipris (Copyright, N. Dessipris 1991)
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* Written on: 08/05/1991
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* Modified on:
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* 11/3/01 JC
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* - rewritten, calling im_conv() and im_maxvalue()
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*/
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/*
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This file is part of VIPS.
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VIPS is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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/*
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These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif /*HAVE_CONFIG_H*/
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#include <vips/intl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <limits.h>
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#include <assert.h>
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#include <vips/vips.h>
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#ifdef WITH_DMALLOC
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#include <dmalloc.h>
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#endif /*WITH_DMALLOC*/
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int
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im_compass( IMAGE *in, IMAGE *out, INTMASK *mask )
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{
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IMAGE *filtered[8];
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IMAGE *absed[8];
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int i;
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if( im_open_local_array( out, filtered, 8, "im_compass:1", "p" ) ||
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im_open_local_array( out, absed, 8, "im_compass:2", "p" ) )
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return( -1 );
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for( i = 0; i < 8; i++ ) {
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if( im_conv( in, filtered[i], mask ) ||
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!(mask = (INTMASK *) im_local( out,
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(im_construct_fn) im_rotate_imask45,
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(im_callback_fn) im_free_imask,
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mask, mask->filename, NULL )) )
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return( -1 );
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}
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for( i = 0; i < 8; i++ )
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if( im_abs( filtered[i], absed[i] ) )
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return( -1 );
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return( im_maxvalue( absed, out, 8 ) );
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}
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int
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im_lindetect( IMAGE *in, IMAGE *out, INTMASK *mask )
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{
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IMAGE *filtered[4];
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IMAGE *absed[4];
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int i;
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if( im_open_local_array( out, filtered, 4, "im_lindetect:1", "p" ) ||
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im_open_local_array( out, absed, 4, "im_lindetect:2", "p" ) )
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return( -1 );
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for( i = 0; i < 4; i++ ) {
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if( im_conv( in, filtered[i], mask ) ||
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!(mask = (INTMASK *) im_local( out,
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(im_construct_fn) im_rotate_imask45,
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(im_callback_fn) im_free_imask,
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mask, mask->filename, NULL )) )
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return( -1 );
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}
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for( i = 0; i < 4; i++ )
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if( im_abs( filtered[i], absed[i] ) )
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return( -1 );
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return( im_maxvalue( absed, out, 4 ) );
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}
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#define GTEMPS (4)
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int
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im_gradient( IMAGE *in, IMAGE *out, INTMASK *mask )
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{
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IMAGE *t[GTEMPS];
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INTMASK *rmask;
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if( im_open_local_array( out, t, GTEMPS, "im_gradient", "p" ) )
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return( -1 );
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if( !(rmask = (INTMASK *) im_local( out,
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(im_construct_fn) im_rotate_imask90,
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(im_callback_fn) im_free_imask, mask, mask->filename, NULL )) )
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return( -1 );
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if( im_conv( in, t[0], mask ) ||
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im_conv( in, t[1], rmask ) ||
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im_abs( t[0], t[2] ) ||
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im_abs( t[1], t[3] ) ||
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im_add( t[2], t[3], out ) )
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return( -1 );
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return( 0 );
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}
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