| /* im_label_regions.c |
| * |
| * 5/11/09 |
| * - renamed from im_segment() |
| */ |
| |
| /* |
| |
| 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| /** |
| * im_label_regions(): |
| * @test: image to test |
| * @mask: write labelled regions here |
| * @segments: return number of regions here |
| * |
| * The @test image is repeatedly scanned and regions of 4-connected pixels |
| * with the same pixel value found. Every time a region is discovered, those |
| * pixels are marked in @mask with a unique serial number. Once all pixels |
| * have been labelled, the operation returns, setting @segments to the number |
| * of discrete regions which were detected. |
| * |
| * @mask is always a 1-band %IM_BANDFMT_UINT image of the same dimensions as |
| * @test. |
| * |
| * This operation is useful for, for example, blob counting. You can use the |
| * morphological operators to detect and isolate a series of objects, then use |
| * im_label_regions() to number them all. |
| * |
| * Use im_histindexed() to (for example) find blob coordinates. |
| * |
| * See also: im_histindexed() |
| * |
| * Returns: 0 on success, -1 on error. |
| */ |
| int |
| im_label_regions( IMAGE *test, IMAGE *mask, int *segments ) |
| { |
| IMAGE *t[2]; |
| int serial; |
| int *m; |
| int x, y; |
| |
| /* Create the zero mask image. |
| */ |
| if( im_open_local_array( mask, t, 2, "im_label_regions", "p" ) || |
| im_black( t[0], test->Xsize, test->Ysize, 1 ) || |
| im_clip2fmt( t[0], t[1], IM_BANDFMT_INT ) ) |
| return( -1 ); |
| |
| /* Search the mask image, flooding as we find zero pixels. |
| */ |
| if( im_rwcheck( t[1] ) ) |
| return( -1 ); |
| serial = 0; |
| m = (int *) t[1]->data; |
| for( y = 0; y < test->Ysize; y++ ) { |
| for( x = 0; x < test->Xsize; x++ ) { |
| if( !m[x] ) { |
| /* |
| if( im_flood_other_old( t[1], test, |
| x, y, serial ) ) |
| */ |
| if( im_flood_other( test, t[1], |
| x, y, serial, NULL ) ) |
| // if( im_flood_other_old( t[1], test, |
| // x, y, serial ) ) |
| return( -1 ); |
| |
| serial += 1; |
| } |
| } |
| |
| m += test->Xsize; |
| } |
| |
| /* Copy result to mask. |
| */ |
| if( im_copy( t[1], mask ) ) |
| return( -1 ); |
| if( segments ) |
| *segments = serial; |
| |
| return( 0 ); |
| } |