libvips/libsrc/colour/im_rad2float.c

/* Convert Radiance 32bit packed format to float.
 * 3/3/09
 * 	- from LabQ2Lab and Radiance sources
 */

/*

    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

 */

/*

    Sections of this file from Greg Ward and Radiance with kind 
    permission. The Radience copyright notice appears below.

 */

/* ====================================================================
 * The Radiance Software License, Version 1.0
 *
 * Copyright (c) 1990 - 2009 The Regents of the University of California,
 * through Lawrence Berkeley National Laboratory.   All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *         notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *           if any, must include the following acknowledgment:
 *             "This product includes Radiance software
 *                 (http://radsite.lbl.gov/)
 *                 developed by the Lawrence Berkeley National Laboratory
 *               (http://www.lbl.gov/)."
 *       Alternately, this acknowledgment may appear in the software itself,
 *       if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
 *       and "The Regents of the University of California" must
 *       not be used to endorse or promote products derived from this
 *       software without prior written permission. For written
 *       permission, please contact radiance@radsite.lbl.gov.
 *
 * 5. Products derived from this software may not be called "Radiance",
 *       nor may "Radiance" appear in their name, without prior written
 *       permission of Lawrence Berkeley National Laboratory.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Lawrence Berkeley National Laboratory.   For more
 * information on Lawrence Berkeley National Laboratory, please see
 * <http://www.lbl.gov/>.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <vips/intl.h>

#include <stdio.h>
#include <math.h>

#include <vips/vips.h>

#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif /*WITH_DMALLOC*/

/* Begin copy-paste from Radiance sources.
 */

#define  RED		0
#define  GRN		1
#define  BLU		2
#define  CIEX		0	/* or, if input is XYZ... */
#define  CIEY		1
#define  CIEZ		2
#define  EXP		3	/* exponent same for either format */
#define  COLXS		128	/* excess used for exponent */
#define  WHT		3	/* used for RGBPRIMS type */

#undef  BYTE
#define  BYTE 	unsigned char	/* 8-bit unsigned integer */

typedef BYTE  COLR[4];		/* red, green, blue (or X,Y,Z), exponent */

typedef float COLORV;
typedef COLORV  COLOR[3];	/* red, green, blue (or X,Y,Z) */

#define  copycolor(c1,c2)	((c1)[0]=(c2)[0],(c1)[1]=(c2)[1],(c1)[2]=(c2)[2])

static void
colr_color(col, clr)		/* convert short to float color */
register COLOR  col;
register COLR  clr;
{
	double  f;
	
	if (clr[EXP] == 0)
		col[RED] = col[GRN] = col[BLU] = 0.0;
	else {
		f = ldexp(1.0, (int)clr[EXP]-(COLXS+8));
		col[RED] = (clr[RED] + 0.5)*f;
		col[GRN] = (clr[GRN] + 0.5)*f;
		col[BLU] = (clr[BLU] + 0.5)*f;
	}
}

/* End copy-paste from Radiance sources.
 */


void
rad2float( COLR *inp, COLOR *outbuf, int n )        
{
	colr_color(outbuf[0], inp[0]);
	while (--n > 0) {
		outbuf++; inp++;
		if (inp[0][RED] == inp[-1][RED] &&
			    inp[0][GRN] == inp[-1][GRN] &&
			    inp[0][BLU] == inp[-1][BLU] &&
			    inp[0][EXP] == inp[-1][EXP])
			copycolor(outbuf[0], outbuf[-1]);
		else
			colr_color(outbuf[0], inp[0]);
	}
}

int
im_rad2float( IMAGE *in, IMAGE *out )
{
	/* Must be 4-band uchar.
	 */
	if( in->Bands != 4 || in->BandFmt != IM_BANDFMT_UCHAR ||
		in->Coding != IM_CODING_NONE ) {
		im_error( "im_rad2float", "%s",
			_( "not a 4-band uchar uncoded image" ) );
		return( -1 );
	}

	if( im_cp_desc( out, in ) )
		return( -1 );
	out->Bands = 3;
	out->BandFmt = IM_BANDFMT_FLOAT;
	out->Bbits = im_bits_of_fmt( out->BandFmt );

	if( im_wrapone( in, out, 
		(im_wrapone_fn) rad2float, NULL, NULL ) )
		return( -1 );

	return( 0 );
}