| /* @(#) Thresholds an image. Works for any non-complex type. |
| * @(#) Output is a binary image with 0 and 255 only |
| * @(#) Input is either memory mapped or in a buffer. |
| * @(#) |
| * @(#) int im_thresh(imin, imout, threshold) |
| * @(#) IMAGE *imin, *imout; |
| * @(#) double threshold; |
| * @(#) |
| * @(#) Returns 0 on success and -1 on error |
| * |
| * Copyright: 1991, N. Dessipris, J Cupitt |
| * |
| * Author: N. Dessipris, J. Cupitt |
| * Written on: 15/03/1991 |
| * Modified on : |
| */ |
| |
| /* |
| |
| 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 <stdlib.h> |
| |
| #include <vips/vips.h> |
| |
| #ifdef WITH_DMALLOC |
| #include <dmalloc.h> |
| #endif /*WITH_DMALLOC*/ |
| |
| /* Useful: Call a macro with the name, type pairs for all VIPS functions. */ |
| #define BRIGHT 255 |
| #define DARK 0 |
| #define im_for_all_types(A) \ |
| case IM_BANDFMT_UCHAR: A(unsigned char); break; \ |
| case IM_BANDFMT_CHAR: A(signed char); break; \ |
| case IM_BANDFMT_USHORT: A(unsigned short); break; \ |
| case IM_BANDFMT_SHORT: A(signed short); break; \ |
| case IM_BANDFMT_UINT: A(unsigned int); break; \ |
| case IM_BANDFMT_INT: A(signed int); break; \ |
| case IM_BANDFMT_FLOAT: A(float); break; \ |
| case IM_BANDFMT_DOUBLE: A(double); break; |
| |
| /* Replacement for im_thresh */ |
| int |
| im_thresh( in, out, threshold ) |
| IMAGE *in, *out; |
| double threshold; |
| { |
| int x, y; |
| PEL *bu; /* Buffer we write to */ |
| int s, epl; /* Size and els per line */ |
| |
| /* Check our args. */ |
| if( im_iocheck( in, out ) ) |
| return( -1 ); |
| if( in->Coding != IM_CODING_NONE ) { |
| im_error( "im_thresh", "%s", _( "input should be uncoded") ); |
| return(-1); |
| } |
| |
| /* Set up the output header. */ |
| if( im_cp_desc( out, in ) ) |
| return( -1 ); |
| out->BandFmt = IM_BANDFMT_UCHAR; |
| if( im_setupout( out ) ) |
| return( -1 ); |
| |
| /* Make buffer for building o/p in. */ |
| epl = in->Xsize * in->Bands; |
| s = epl * sizeof( PEL ); |
| if( (bu = (PEL *) im_malloc( out, (unsigned)s )) == NULL ) |
| return( -1 ); |
| |
| /* Define what we do for each band element type. */ |
| #define im_thresh_loop(TYPE)\ |
| { TYPE *a = (TYPE *) in->data;\ |
| \ |
| for( y = 0; y < in->Ysize; y++ ) {\ |
| PEL *b = bu;\ |
| \ |
| for( x = 0; x < epl; x++ ) {\ |
| double f = (double) *a++;\ |
| if ( f >= threshold)\ |
| *b++ = (PEL)BRIGHT;\ |
| else\ |
| *b++ = (PEL)DARK;\ |
| }\ |
| \ |
| if( im_writeline( y, out, bu ) ) \ |
| return( -1 );\ |
| }\ |
| } |
| |
| /* Do the above for all image types. */ |
| switch( in->BandFmt ) { |
| im_for_all_types( im_thresh_loop ); |
| |
| default: |
| im_error( "im_thresh", "%s", _( "Unknown input format") ); |
| return( -1 ); |
| } |
| |
| return( 0 ); |
| } |
