libvips/libsrc/histograms_lut/im_identity.c

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2007-08-29 18:23:50 +02:00
/* @(#) Creates a image file with Xsize=256, Ysize=1, Bands=bands,
* @(#) Bbits=IM_BBITS_BYTE, BandFmt=IM_BANDFMT_UCHAR, Type=IM_TYPE_HISTOGRAM;
* @(#)
* @(#) The created image consist a n bands linear lut and is the basis
* @(#) for building up look-up tables.
* @(#)
* @(#) int im_identity(lut, bands)
* @(#) IMAGE *lut;
* @(#) int bands;
* @(#)
* @(#) As above, but make a ushort LUT. ushort LUTs can be less than 65536
* @(#) elements - sz is the number of elements required.
* @(#)
* @(#) int im_identity_ushort(lut, bands, sz)
* @(#) IMAGE *lut;
* @(#) int bands;
* @(#) int sz;
* @(#)
* @(#) Returns -1 on error and 0 on success
* @(#)
*
* Copyright 1991, N. Dessipris.
*
* Author N. Dessipris
* Written on 11/03/1991
* Updated on:
* 18/6/93 JC
* - im_outcheck() call added
* - ANSIfied
* 24/8/94 JC
* - im_identity_ushort() 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_identity( IMAGE *lut, int bands )
{
unsigned char *buf, *p;
int x, z;
/* Check input args
*/
if( im_outcheck( lut ) )
return( -1 );
if( bands < 0 ) {
im_errormsg( "im_identity: bad bands" );
return( -1 );
}
/* Set new image properly.
*/
im_initdesc( lut,
256, 1, bands, IM_BBITS_BYTE, IM_BANDFMT_UCHAR,
IM_CODING_NONE, IM_TYPE_HISTOGRAM, 1.0, 1.0, 0, 0 );
/* Make output.
*/
if( im_setupout( lut ) )
return( -1 );
/* Create output buffer.
*/
if( !(buf = (unsigned char *) im_malloc( lut, bands * 256 )) )
return( -1 );
/* Write ramp.
*/
for( p = buf, x = 0; x < 256; x++ )
for( z = 0; z < bands; z++ )
*p++ = x;
if( im_writeline( 0, lut, buf ) )
return( -1 );
return( 0 );
}
int
im_identity_ushort( IMAGE *lut, int bands, int sz )
{
unsigned short *buf, *p;
int x, z;
/* Check input args
*/
if( im_outcheck( lut ) )
return( -1 );
if( sz > 65536 || sz < 0 ) {
im_errormsg( "im_identity_ushort: bad size" );
return( -1 );
}
if( bands < 0 ) {
im_errormsg( "im_identity_ushort: bad bands" );
return( -1 );
}
/* Set new image.
*/
im_initdesc( lut,
sz, 1, bands, IM_BBITS_SHORT, IM_BANDFMT_USHORT,
IM_CODING_NONE, IM_TYPE_HISTOGRAM, 1.0, 1.0, 0, 0 );
/* Make output.
*/
if( im_setupout( lut ) )
return( -1 );
/* Create output buffer.
*/
if( !(buf = (unsigned short *)
im_malloc( lut, sz * bands * sizeof( unsigned short ) )) )
return( -1 );
/* Write ramp.
*/
for( p = buf, x = 0; x < sz; x++ )
for( z = 0; z < bands; z++ )
*p++ = x;
if( im_writeline( 0, lut, (PEL *) buf ) )
return( -1 );
return( 0 );
}