libvips/libsrc/other/im_simcontr.c

134 lines
3.2 KiB
C

/* @(#) creates a pattern showing the similtaneous constrast effect
* @(#)
* @(#) Usage: int im_simcontr(image, xs, ys)
* @(#) IMAGE *image;
* @(#) int xs, ys;
* @(#)
* @(#) Returns 0 on success and -1 on error
* @(#)
*
* Copyright: 1990, N. Dessipris.
*
* Author: Nicos Dessipris
* Written on: 19/07/1991
* Modified on:
* 22/7/93 JC
* - externs removed
* - im_outcheck() added
*/
/*
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 <math.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
int
im_simcontr( IMAGE *image, int xs, int ys )
{
int x, y;
unsigned char *line1, *line2, *cpline;
/* Check input args */
if( im_outcheck( image ) )
return( -1 );
/* Set now image properly */
im_initdesc(image, xs, ys, 1, IM_BBITS_BYTE, IM_BANDFMT_UCHAR,
IM_CODING_NONE, IM_TYPE_B_W, 1.0, 1.0, 0, 0 );
/* Set up image checking whether the output is a buffer or a file */
if (im_setupout( image ) == -1 )
{ im_errormsg("im_simcontr: im_setupout failed"); return(-1); }
/* Create data */
line1 = (unsigned char *)calloc((unsigned)xs, sizeof(char));
line2 = (unsigned char *)calloc((unsigned)xs, sizeof(char));
if ( (line1 == NULL) || (line2 == NULL) )
{ im_errormsg("im_simcontr: calloc failed"); return(-1); }
cpline = line1;
for (x=0; x<xs; x++)
*cpline++ = (PEL)255;
cpline = line1;
for (x=0; x<xs/2; x++)
*cpline++ = (PEL)0;
cpline = line2;
for (x=0; x<xs; x++)
*cpline++ = (PEL)255;
cpline = line2;
for (x=0; x<xs/8; x++)
*cpline++ = (PEL)0;
for (x=0; x<xs/4; x++)
*cpline++ = (PEL)128;
for (x=0; x<xs/8; x++)
*cpline++ = (PEL)0;
for (x=0; x<xs/8; x++)
*cpline++ = (PEL)255;
for (x=0; x<xs/4; x++)
*cpline++ = (PEL)128;
for (y=0; y<ys/4; y++)
{
if ( im_writeline( y, image, (PEL *)line1 ) == -1 )
{
free ( (char *)line1 ); free ( (char *)line2 );
return( -1 );
}
}
for (y=ys/4; y<(ys/4+ys/2); y++)
{
if ( im_writeline( y, image, (PEL *)line2 ) == -1 )
{
free ( (char *)line1 ); free ( (char *)line2 );
return( -1 );
}
}
for (y=(ys/4 + ys/2); y<ys; y++)
{
if ( im_writeline( y, image, (PEL *)line1 ) == -1 )
{
free ( (char *)line1 ); free ( (char *)line2 );
return( -1 );
}
}
free ( (char *)line1 ); free ( (char *)line2 );
return(0);
}