| /* @(#) Function which calculates the number of transitions |
| * @(#) between black and white for the horizontal or the vertical |
| * @(#) direction of an image. black<128 , white>=128 |
| * @(#) The function calculates the number of transitions for all |
| * @(#) Xsize or Ysize and returns the mean of the result |
| * @(#) Input should be binary one channel |
| * @(#) |
| * @(#) int im_cntlines(im, nolines, flag) |
| * @(#) IMAGE *im; |
| * @(#) float *nolines; |
| * @(#) int flag; 0 to cnt horizontal and 1 to count vertical lines |
| * @(#) |
| * @(#) Returns 0 on success and -1 on error |
| * |
| * Copyright: 1990, N. Dessipris. |
| * |
| * Author: Nicos Dessipris |
| * Written on: 02/05/1990 |
| * Modified on : |
| * |
| * 19/9/95 JC |
| * - tidied up |
| */ |
| |
| /* |
| |
| 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*/ |
| |
| int |
| im_cntlines( IMAGE *im, double *nolines, int flag ) |
| { |
| int x, y; |
| PEL *line; |
| int cnt; |
| |
| /* Is im valid? |
| */ |
| if( im_incheck( im ) ) |
| return( -1 ); |
| if( im->Coding != IM_CODING_NONE || im->BandFmt != IM_BANDFMT_UCHAR || |
| im->Bands != 1 ) { |
| im_error( "im_cntlines", "%s", |
| _( "1-band uchar uncoded only" ) ); |
| return( -1 ); |
| } |
| if( flag != 0 && flag != 1 ) { |
| im_error( "im_cntlines", "%s", |
| _( "flag should be 0 (horizontal) or 1 (vertical)" ) ); |
| return( -1 ); |
| } |
| |
| line = (PEL *) im->data; |
| if( flag == 1 ) { |
| /* Count vertical lines. |
| */ |
| for( cnt = 0, y = 0; y < im->Ysize; y++ ) { |
| PEL *p = line; |
| |
| for( x = 0; x < im->Xsize - 1; x++ ) { |
| if( p[0] < (PEL)128 && p[1] >= (PEL)128 ) |
| cnt++; |
| else if( p[0] >= (PEL)128 && p[1] < (PEL)128 ) |
| cnt++; |
| |
| p++; |
| } |
| |
| line += im->Xsize; |
| } |
| |
| *nolines = (float) cnt / (2.0 * im->Ysize); |
| } |
| else { |
| /* Count horizontal lines. |
| */ |
| for( cnt = 0, y = 0; y < im->Ysize - 1; y++ ) { |
| PEL *p1 = line; |
| PEL *p2 = line + im->Xsize; |
| |
| for( x = 0; x < im->Xsize; x++ ) { |
| if( *p1 < (PEL)128 && *p2 >= (PEL)128 ) |
| cnt++; |
| else if( *p1 >= (PEL)128 && *p2 < (PEL)128 ) |
| cnt++; |
| |
| p1++; |
| p2++; |
| } |
| |
| line += im->Xsize; |
| } |
| |
| *nolines = (float)cnt / (2.0 * im->Xsize); |
| } |
| |
| return( 0 ); |
| } |