| /* @(#) Functions which detects the +ve and -ve edges of |
| * @(#) zero crossings of an image depending on the flag |
| * @(#) Function im_zerox() assumes that the imin file is an integer image |
| * @(#) either memory mapped or in a buffer. |
| * @(#) The output image is byte with |
| * @(#) zero crossing set to 255 and all othre values set to zero |
| * @(#) |
| * @(#) int im_zerox(pimin, pimout, flag) |
| * @(#) IMAGE *pimin, *pimout; |
| * @(#) int flag; |
| * @(#) |
| * @(#) All functions return 0 on success and -1 on error |
| * @(#) |
| * |
| * Copyright: 1990, N. Dessipris. |
| * |
| * Author: Nicos Dessipris |
| * Written on: 12/02/1990 |
| * Modified on : |
| * 1/2/95 JC |
| * - rewritten for PIO |
| * - some bugs removed |
| * 11/5/06 |
| * - small clean ups |
| */ |
| |
| /* |
| |
| 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*/ |
| |
| #define loop( TYPE ) \ |
| for( i = 0; i < ne; i++ ) { \ |
| TYPE p1 = ((TYPE *)p)[i]; \ |
| TYPE p2 = ((TYPE *)p)[i + ba]; \ |
| \ |
| if( flag == 1 && p1 > 0 && p2 <= 0 ) \ |
| q[i] = 255; \ |
| else if( flag == -1 && p1 < 0 && p2 >= 0 ) \ |
| q[i] = 255; \ |
| else \ |
| q[i] = 0; \ |
| } |
| |
| /* Zerox generate function. |
| */ |
| static int |
| zerox_gen( REGION *or, void *seq, void *a, void *b ) |
| { |
| REGION *ir = (REGION *) seq; |
| IMAGE *in = (IMAGE *) a; |
| int flag = GPOINTER_TO_INT( b ); |
| Rect irect; |
| Rect *r = &or->valid; |
| |
| /* Range of pixels we loop over. |
| */ |
| int le = r->left; |
| int to = r->top; |
| int bo = IM_RECT_BOTTOM( r ); |
| int ba = in->Bands; |
| int ne = ba * r->width; |
| |
| int i, y; |
| |
| /* We need to be able to see one pixel to the right. |
| */ |
| irect.top = r->top; |
| irect.left = r->left; |
| irect.width = r->width + 1; |
| irect.height = r->height; |
| if( im_prepare( ir, &irect ) ) |
| return( -1 ); |
| |
| for( y = to; y < bo; y++ ) { |
| PEL *p = (PEL *) IM_REGION_ADDR( ir, le, y ); |
| PEL *q = (PEL *) IM_REGION_ADDR( or, le, y ); |
| |
| switch( in->BandFmt ) { |
| case IM_BANDFMT_CHAR: loop( signed char ); break; |
| case IM_BANDFMT_SHORT: loop( signed short ); break; |
| case IM_BANDFMT_INT: loop( signed int ); break; |
| case IM_BANDFMT_FLOAT: loop( float ); break; |
| case IM_BANDFMT_DOUBLE: loop( double ); break; |
| |
| default: |
| error_exit( "im_zerox: internal error" ); |
| /*NOTREACHED*/ |
| } |
| } |
| |
| return( 0 ); |
| } |
| |
| int |
| im_zerox( IMAGE *in, IMAGE *out, int flag ) |
| { |
| IMAGE *t1 = im_open_local( out, "im_zerox#1" , "p" ); |
| |
| if( !t1 ) |
| return( -1 ); |
| if( flag != -1 && flag != 1 ) { |
| im_error( "im_zerox", "%s", _( "flag not -1 or 1" ) ); |
| return( -1 ); |
| } |
| if( im_piocheck( in, t1 ) ) |
| return( -1 ); |
| if( vips_bandfmt_iscomplex( in->BandFmt ) || |
| in->Coding != IM_CODING_NONE ) { |
| im_error( "im_zerox", "%s", _( "non-complex uncoded only" ) ); |
| return( -1 ); |
| } |
| if( in->Xsize < 2 ) { |
| im_error( "im_zerox", "%s", _( "image too narrow" ) ); |
| return( -1 ); |
| } |
| if( vips_bandfmt_isuint( in->BandFmt ) ) |
| /* Unsigned type, therefore there will be no zero-crossings. |
| */ |
| return( im_black( out, in->Xsize, in->Ysize, in->Bands ) ); |
| |
| /* Force output to be BYTE. Output is narrower than input by 1 pixel. |
| */ |
| if( im_cp_desc( t1, in ) ) |
| return( -1 ); |
| t1->BandFmt = IM_BANDFMT_UCHAR; |
| t1->Xsize -= 1; |
| |
| /* Set hints - THINSTRIP is ok with us. |
| */ |
| if( im_demand_hint( t1, IM_THINSTRIP, NULL ) ) |
| return( -1 ); |
| |
| /* Generate image. |
| */ |
| if( im_generate( t1, im_start_one, zerox_gen, im_stop_one, |
| in, GINT_TO_POINTER( flag ) ) ) |
| return( -1 ); |
| |
| /* Now embed it in a larger image. |
| */ |
| if( im_embed( t1, out, 0, 0, 0, in->Xsize, in->Ysize ) ) |
| return( -1 ); |
| |
| return( 0 ); |
| } |