libvips/libsrc/arithmetic/im_fav4.c

96 lines
2.4 KiB
C

/* @(#) Optimised 4 frame average
Copyright (C) 1992, Kirk Martinez, History of Art Dept, Birkbeck College
*/
/*
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 <stdlib.h>
#include <string.h>
#include <vips/vips.h>
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/
#define ARGS "fav4: frame average 4 frames\nARGS: im1 im2 im3 im4 outfile"
#define NFRAMES 4
/* @(#) Optimised 4 frame average
Copyright (C) 1992, Kirk Martinez, History of Art Dept, Birkbeck College
CHAR images only!
ARGS: array of 4 source images and output image
*/
int
im_fav4( IMAGE **in, IMAGE *out)
{
PEL *result, *buffer, *p1, *p2, *p3, *p4;
int x,y;
int linebytes, PICY;
/* check IMAGEs parameters
*/
if(im_iocheck(in[1], out)) return(-1);
/* BYTE images only!
*/
if( (in[0]->BandFmt != IM_BANDFMT_CHAR) && (in[0]->BandFmt != IM_BANDFMT_UCHAR)) return(-1);
if ( im_cp_desc(out, in[1]) == -1) /* copy image descriptors */
return(-1);
if ( im_setupout(out) == -1)
return(-1);
linebytes = in[0]->Xsize * in[0]->Bands;
PICY = in[0]->Ysize;
buffer = (PEL*)im_malloc(NULL,linebytes);
memset(buffer, 0, linebytes);
p1 = (PEL*)in[0]->data;
p2 = (PEL*)in[1]->data;
p3 = (PEL*)in[2]->data;
p4 = (PEL*)in[3]->data;
for (y = 0; y < PICY; y++)
{
result = buffer;
/* average 4 pels with rounding, for whole line*/
for (x = 0; x < linebytes; x++) {
*result++ = (PEL)((int)((int)*p1++ + (int)*p2++ + (int)*p3++ + (int)*p4++ +2) >> 2);
}
im_writeline(y,out, buffer);
}
im_free(buffer);
return(0);
}