158 lines
3.9 KiB
C
158 lines
3.9 KiB
C
/* @(#) Slices an image using two thresholds. Works for any non-complex type.
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* @(#) Output has three levels 0 128 and 255. Values below or = t1 are 0,
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* @(#) above t2 are 255 and the remaining are 128.
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* @(#) Input is either memory mapped or in a buffer.
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* @(#) It is implied that t1 is less than t2; however the program checks
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* @(#) if they are the wrong way and swaps them
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* @(#)
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* @(#) int im_slice(in, out, t1, t2)
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* @(#) IMAGE *in, *out;
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* @(#) double t1, t2;
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* @(#)
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* @(#) Returns 0 on success and -1 on error
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*
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* Copyright: 1991, N. Dessipris
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*
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* Author: N. Dessipris
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* Written on: 15/03/1991
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* Modified on :
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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 <math.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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#define BRIGHT 255
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#define GREY 128
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#define DARK 0
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/* Useful: Call a macro with the name, type pairs for all VIPS functions.
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*/
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#define im_for_all_types(A) \
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case IM_BANDFMT_UCHAR: A(unsigned char); break; \
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case IM_BANDFMT_CHAR: A(signed char); break; \
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case IM_BANDFMT_USHORT: A(unsigned short); break; \
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case IM_BANDFMT_SHORT: A(signed short); break; \
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case IM_BANDFMT_UINT: A(unsigned int); break; \
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case IM_BANDFMT_INT: A(signed int); break; \
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case IM_BANDFMT_FLOAT: A(float); break;
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/* Replacement for im_slice */
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int
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im_slice( in, out, t1, t2 )
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IMAGE *in, *out;
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double t1, t2;
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{
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int x, y, z;
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PEL *bu; /* Buffer we write to */
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int s, epl; /* Size and els per line */
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double thresh1, thresh2;
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/* Check our args. */
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if( im_iocheck( in, out ) )
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{
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im_errormsg("im_slice: im_iocheck failed");
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return( -1 );
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}
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if( in->Coding != IM_CODING_NONE )
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{
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im_errormsg("im_slice: input should be uncoded");
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return( -1 );
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}
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/* Set up the output header. */
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if( im_cp_desc( out, in ) )
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{
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im_errormsg("im_slice: im_cp_desc failed");
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return( -1 );
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}
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out->BandFmt = IM_BANDFMT_UCHAR;
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out->Bbits = IM_BBITS_BYTE;
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if( im_setupout( out ) )
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{
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im_errormsg("im_slice: im_setupout failed");
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return( -1 );
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}
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if ( t1 <= t2 )
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{ thresh1 = t1; thresh2 = t2; }
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else
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{ thresh1 = t2; thresh2 = t1; }
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/* Make buffer for building o/p in. */
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epl = in->Xsize * in->Bands;
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s = epl * sizeof( PEL );
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if( (bu = (PEL *) im_malloc( out, (unsigned)s )) == NULL )
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return( -1 );
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/* Define what we do for each band element type. */
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#define im_slice_loop(TYPE)\
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{ TYPE *a = (TYPE *) in->data;\
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\
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for( y = 0; y < in->Ysize; y++ ) {\
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PEL *b = bu;\
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\
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for( x = 0; x < in->Xsize; x++ )\
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for( z = 0; z < in->Bands; z++ ) {\
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double f = (double) *a++;\
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if ( f <= thresh1)\
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*b++ = (PEL)DARK;\
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else if ( f > thresh2 )\
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*b++ = (PEL)BRIGHT;\
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else \
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*b++ = (PEL)GREY;\
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}\
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\
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if( im_writeline( y, out, bu ) )\
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return( -1 );\
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}\
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}
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/* Do the above for all image types. */
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switch( in->BandFmt ) {
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im_for_all_types( im_slice_loop );
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default:
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im_errormsg("im_slice: Unknown input format");
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return( -1 );
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}
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return( 0 );
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}
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