The RADIANCE Picture File Format

Radiance is a lighting simulation and rendering system available by
anonymous ftp from hobbes.lbl.gov (128.3.12.38).  The picture file
format used by the program uses a floating point representation that
provides greater fidelity and numerical accuracy over a 24-bit
image, without taking much extra space.

At the end of this message I have put a shar file of the routines you
need to read and write Radiance pictures.  The format has been
enhanced slightly for the next release (in an upward compatible
way), so you should definitely use these newer routines.

The file format, like most binary files used by Radiance, contains
an ASCII information header that is terminated by an empty line.
This header typically begins with the line "#?RADIANCE", followd
by the commands used to generate the file, along with variables
indicating exposure, view parameters, and so on.  Next there is a
single line that indicates the resolution and pixel scanning order of
the image.  For Radiance pictures, the pixels are order as English
text, left to right and top to bottom.  This is indicated with a line
of the form:

-Y M +X N

Where M and N are the y and x resolutions, respectively.  The x and y
image coordinates are always the same, starting with (0,0) at the lower
left corner, (N,0) at the lower right, and (0,M) at the upper left.
The y resolution appears first in our specification because it is the
major sort, and is preceded by a minus sign because it is decreasing in
the file.

Finally, the floating point scanlines follow.  Each pixel is represented by
at most 4 bytes.  The first three bytes are the red, green and blue mantissas
(in that order), and the fourth byte is a common exponent.  The floating point
color (R,G,B)=(1.,.5,.25) would be represented by the bytes (128,64,32,129).
The conversion back to floating point is possible using the ldexp() library
routine, or it's better to use the colr_color() routine included in color.c.

The scanlines are usually run-length encoded.  My previous scheme (release 1.4
and earlier) used a simple count for repeated pixels.  My new scheme is
more complicated and encodes the four components separately.  I don't
recommend writing your own routine to decode it -- use what's in color.c.

A skeletal program to read a Radiance picture file and convert to 24-bit
gamma-corrected color looks like this:

/* Copyright (c) 1992 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "@(#)ra_skel.c 2.9 2/27/94 LBL";
#endif

/*
 *  Skeletal 24-bit image conversion program.  Replace "skel"
 *  in this file with a more appropriate image type identifier.
 *
 *  The Rmakefile entry should look something like this:
 *	ra_skel:	ra_skel.o
 *		cc $(CFLAGS) -o ra_skel ra_skel.o -lrt -lm
 *	ra_skel.o:	../common/color.h ../common/resolu.h
 *
 *  If you like to do things the hard way, you can link directly
 *  to the object files "color.o colrops.o resolu.o header.o" in
 *  the common subdirectory instead of using the -lrt library.
 */

#include  <stdio.h>
#include  <math.h>
#ifdef MSDOS
#include  <fcntl.h>
#endif
#include  "color.h"
#include  "resolu.h"

extern char  *malloc();

double	gamcor = 2.2;			/* gamma correction */

int  bradj = 0;				/* brightness adjustment */

char  *progname;

int  xmax, ymax;


main(argc, argv)
int  argc;
char  *argv[];
{
	int  reverse = 0;
	int  i;
	
	progname = argv[0];

	for (i = 1; i < argc; i++)
		if (argv[i][0] == '-')
			switch (argv[i][1]) {
			case 'g':		/* gamma correction */
				gamcor = atof(argv[++i]);
				break;
			case 'e':		/* exposure adjustment */
				if (argv[i+1][0] != '+' && argv[i+1][0] != '-')
					goto userr;
				bradj = atoi(argv[++i]);
				break;
			case 'r':		/* reverse conversion */
				reverse = 1;
				break;
			default:
				goto userr;
			}
		else
			break;

	if (i < argc-2)
		goto userr;
	if (i <= argc-1 && freopen(argv[i], "r", stdin) == NULL) {
		fprintf(stderr, "%s: can't open input \"%s\"\n",
				progname, argv[i]);
		exit(1);
	}
	if (i == argc-2 && freopen(argv[i+1], "w", stdout) == NULL) {
		fprintf(stderr, "%s: can't open output \"%s\"\n",
				progname, argv[i+1]);
		exit(1);
	}
#ifdef MSDOS
	setmode(fileno(stdin), O_BINARY);
	setmode(fileno(stdout), O_BINARY);
#endif
	setcolrgam(gamcor);		/* set up gamma correction */
	if (reverse) {
					/* get their image resolution */
		read_skel_head(&xmax, &ymax);
					/* put our header */
		newheader("RADIANCE", stdout);
		printargs(i, argv, stdout);
		fputformat(COLRFMT, stdout);
		putchar('\n');
		fprtresolu(xmax, ymax, stdout);
					/* convert file */
		skel2ra();
	} else {
					/* get our header */
		if (checkheader(stdin, COLRFMT, NULL) < 0 ||
				fgetresolu(&xmax, &ymax, stdin) < 0)
			quiterr("bad picture format");
					/* write their header */
		write_skel_head(xmax, ymax);
					/* convert file */
		ra2skel();
	}
	exit(0);
userr:
	fprintf(stderr,
		"Usage: %s [-r][-g gamma][-e +/-stops] [input [output]]\n",
			progname);
	exit(1);
}


quiterr(err)		/* print message and exit */
char  *err;
{
	if (err != NULL) {
		fprintf(stderr, "%s: %s\n", progname, err);
		exit(1);
	}
	exit(0);
}


skel2ra()		/* convert 24-bit scanlines to Radiance picture */
{
	COLR	*scanout;
	register int	x;
	int	y;
						/* allocate scanline */
	scanout = (COLR *)malloc(xmax*sizeof(COLR));
	if (scanout == NULL)
		quiterr("out of memory in skel2ra");
						/* convert image */
	for (y = ymax-1; y >= 0; y--) {
		for (x = 0; x < xmax; x++) {
			scanout[x][RED] = getc(stdin);
			scanout[x][GRN] = getc(stdin);
			scanout[x][BLU] = getc(stdin);
		}
		if (feof(stdin) | ferror(stdin))
			quiterr("error reading skel image");
						/* undo gamma */
		gambs_colrs(scanout, xmax);
		if (bradj)			/* adjust exposure */
			shiftcolrs(scanout, xmax, bradj);
		if (fwritecolrs(scanout, xmax, stdout) < 0)
			quiterr("error writing Radiance picture");
	}
						/* free scanline */
	free((char *)scanout);
}


ra2skel()		/* convert Radiance scanlines to 24-bit */
{
	COLR	*scanin;
	register int	x;
	int	y;
						/* allocate scanline */
	scanin = (COLR *)malloc(xmax*sizeof(COLR));
	if (scanin == NULL)
		quiterr("out of memory in ra2skel");
						/* convert image */
	for (y = ymax-1; y >= 0; y--) {
		if (freadcolrs(scanin, xmax, stdin) < 0)
			quiterr("error reading Radiance picture");
		if (bradj)			/* adjust exposure */
			shiftcolrs(scanin, xmax, bradj);
		colrs_gambs(scanin, xmax);	/* gamma correction */
		for (x = 0; x < xmax; x++) {
			putc(scanin[x][RED], stdout);
			putc(scanin[x][GRN], stdout);
			putc(scanin[x][BLU], stdout);
		}
		if (ferror(stdout))
			quiterr("error writing skel file");
	}
						/* free scanline */
	free((char *)scanin);
}
--------------------------------------------------------------

You will find all the routines you need in ray/src/common.  The
checkheader() routine is in the module header.c, fgetresolu is in resolu.c,
freadcolrs() is in color.c, and setcolrgam() and colrs_gambs() are
in the module colrops.c.

If you want to convert the file to 8-bit color, the process is quite a
bit more complicated.  I suggest you take a look at the ra_t8.c program
in the ray/src/px directory to get a better idea of what is involved.

------------------------------
#! /bin/sh
# This is a shell archive, meaning:
# 1. Remove everything above the #! /bin/sh line.
# 2. Save the resulting text in a file.
# 3. Execute the file with /bin/sh (not csh) to create:
#	color.h
#	resolu.h
#	resolu.c
#	header.c
#	color.c
#	colrops.c
# This archive created: Tue Apr  5 14:07:02 1994
export PATH; PATH=/bin:/usr/bin:$PATH
if test -f 'color.h'
then
	echo shar: "will not over-write existing file 'color.h'"
else
sed 's/^X//' << \SHAR_EOF > 'color.h'
X/* Copyright (c) 1991 Regents of the University of California */
X
X/* SCCSid "@(#)color.h 2.6 8/2/93 LBL" */
X
X/*
X *  color.h - header for routines using pixel color values.
X *
X *     12/31/85
X *
X *  Two color representations are used, one for calculation and
X *  another for storage.  Calculation is done with three floats
X *  for speed.  Stored color values use 4 bytes which contain
X *  three single byte mantissas and a common exponent.
X */
X
X#define  RED		0
X#define  GRN		1
X#define  BLU		2
X#define  EXP		3
X#define  COLXS		128	/* excess used for exponent */
X
Xtypedef unsigned char  BYTE;	/* 8-bit unsigned integer */
X
Xtypedef BYTE  COLR[4];		/* red, green, blue, exponent */
X
X#define  copycolr(c1,c2)	(c1[0]=c2[0],c1[1]=c2[1], \
X				c1[2]=c2[2],c1[3]=c2[3])
X
Xtypedef float  COLOR[3];	/* red, green, blue */
X
X#define  colval(col,pri)	((col)[pri])
X
X#define  setcolor(col,r,g,b)	((col)[RED]=(r),(col)[GRN]=(g),(col)[BLU]=(b))
X
X#define  copycolor(c1,c2)	((c1)[0]=(c2)[0],(c1)[1]=(c2)[1],(c1)[2]=(c2)[2])
X
X#define  scalecolor(col,sf)	((col)[0]*=(sf),(col)[1]*=(sf),(col)[2]*=(sf))
X
X#define  addcolor(c1,c2)	((c1)[0]+=(c2)[0],(c1)[1]+=(c2)[1],(c1)[2]+=(c2)[2])
X
X#define  multcolor(c1,c2)	((c1)[0]*=(c2)[0],(c1)[1]*=(c2)[1],(c1)[2]*=(c2)[2])
X
X#ifdef  NTSC
X#define  bright(col)		(.295*(col)[RED]+.636*(col)[GRN]+.070*(col)[BLU])
X#define  normbright(c)		(int)((74L*(c)[RED]+164L*(c)[GRN]+18L*(c)[BLU])>>8)
X#else
X#define  bright(col)		(.263*(col)[RED]+.655*(col)[GRN]+.082*(col)[BLU])
X#define  normbright(c)		(int)((67L*(c)[RED]+168L*(c)[GRN]+21L*(c)[BLU])>>8)
X#endif
X
X				/* luminous efficacies over visible spectrum */
X#define  MAXEFFICACY		683.		/* defined maximum at 550 nm */
X#define  WHTEFFICACY		179.		/* uniform white light */
X#define  D65EFFICACY		203.		/* standard illuminant D65 */
X#define  INCEFFICACY		160.		/* illuminant A (incand.) */
X#define  SUNEFFICACY		208.		/* illuminant B (solar dir.) */
X#define  SKYEFFICACY		D65EFFICACY	/* skylight */
X#define  DAYEFFICACY		D65EFFICACY	/* combined sky and solar */
X
X#define  luminance(col)		(WHTEFFICACY * bright(col))
X
X#define  intens(col)		( (col)[0] > (col)[1] \
X				? (col)[0] > (col)[2] ? (col)[0] : (col)[2] \
X				: (col)[1] > (col)[2] ? (col)[1] : (col)[2] )
X
X#define  colrval(c,p)		( (c)[EXP] ? \
X				ldexp((c)[p]+.5,(int)(c)[EXP]-(COLXS+8)) : \
X				0. )
X
X#define  WHTCOLOR		{1.0,1.0,1.0}
X#define  BLKCOLOR		{0.0,0.0,0.0}
X#define  WHTCOLR		{128,128,128,COLXS+1}
X#define  BLKCOLR		{0,0,0,0}
X
X				/* picture format identifier */
X#define  COLRFMT		"32-bit_rle_rgbe"
X
X				/* macros for exposures */
X#define  EXPOSSTR		"EXPOSURE="
X#define  LEXPOSSTR		9
X#define  isexpos(hl)		(!strncmp(hl,EXPOSSTR,LEXPOSSTR))
X#define  exposval(hl)		atof((hl)+LEXPOSSTR)
X#define  fputexpos(ex,fp)	fprintf(fp,"%s%e\n",EXPOSSTR,ex)
X
X				/* macros for pixel aspect ratios */
X#define  ASPECTSTR		"PIXASPECT="
X#define  LASPECTSTR		10
X#define  isaspect(hl)		(!strncmp(hl,ASPECTSTR,LASPECTSTR))
X#define  aspectval(hl)		atof((hl)+LASPECTSTR)
X#define  fputaspect(pa,fp)	fprintf(fp,"%s%f\n",ASPECTSTR,pa)
X
X				/* macros for color correction */
X#define  COLCORSTR		"COLORCORR="
X#define  LCOLCORSTR		10
X#define  iscolcor(hl)		(!strncmp(hl,COLCORSTR,LCOLCORSTR))
X#define  colcorval(cc,hl)	sscanf(hl+LCOLCORSTR,"%f %f %f", \
X					&(cc)[RED],&(cc)[GRN],&(cc)[BLU])
X#define  fputcolcor(cc,fp)	fprintf(fp,"%s %f %f %f\n",COLCORSTR, \
X					(cc)[RED],(cc)[GRN],(cc)[BLU])
X
X#ifdef  DCL_ATOF
Xextern double  atof(), ldexp(), frexp();
X#endif
SHAR_EOF
fi
if test -f 'resolu.h'
then
	echo shar: "will not over-write existing file 'resolu.h'"
else
sed 's/^X//' << \SHAR_EOF > 'resolu.h'
X/* Copyright (c) 1991 Regents of the University of California */
X
X/* SCCSid "@(#)resolu.h 2.2 6/4/93 LBL" */
X
X/*
X * Definitions for resolution line in image file.
X *
X * True image orientation is defined by an xy coordinate system
X * whose origin is at the lower left corner of the image, with
X * x increasing to the right and y increasing in the upward direction.
X * This true orientation is independent of how the pixels are actually
X * ordered in the file, which is indicated by the resolution line.
X * This line is of the form "{+-}{XY} xyres {+-}{YX} yxres\n".
X * A typical line for a 1024x600 image might be "-Y 600 +X 1024\n",
X * indicating that the scanlines are in English text order (PIXSTANDARD).
X */
X
X			/* flags for scanline ordering */
X#define  XDECR			1
X#define  YDECR			2
X#define  YMAJOR			4
X
X			/* standard scanline ordering */
X#define  PIXSTANDARD		(YMAJOR|YDECR)
X#define  PIXSTDFMT		"-Y %d +X %d\n"
X
X			/* structure for image dimensions */
Xtypedef struct {
X	int	or;		/* orientation (from flags above) */
X	int	xr, yr;		/* x and y resolution */
X} RESOLU;
X
X			/* macros to get scanline length and number */
X#define  scanlen(rs)		((rs)->or & YMAJOR ? (rs)->xr : (rs)->yr)
X#define  numscans(rs)		((rs)->or & YMAJOR ? (rs)->yr : (rs)->xr)
X
X			/* resolution string buffer and its size */
X#define  RESOLU_BUFLEN		32
Xextern char  resolu_buf[RESOLU_BUFLEN];
X
X			/* macros for reading/writing resolution struct */
X#define  fputsresolu(rs,fp)	fputs(resolu2str(resolu_buf,rs),fp)
X#define  fgetsresolu(rs,fp)	str2resolu(rs, \
X					fgets(resolu_buf,RESOLU_BUFLEN,fp))
X
X			/* reading/writing of standard ordering */
X#define  fprtresolu(sl,ns,fp)	fprintf(fp,PIXSTDFMT,ns,sl)
X#define  fscnresolu(sl,ns,fp)	(fscanf(fp,PIXSTDFMT,ns,sl)==2)
X
Xextern char  *resolu2str();
SHAR_EOF
fi
if test -f 'resolu.c'
then
	echo shar: "will not over-write existing file 'resolu.c'"
else
sed 's/^X//' << \SHAR_EOF > 'resolu.c'
X/* Copyright (c) 1991 Regents of the University of California */
X
X#ifndef lint
Xstatic char SCCSid[] = "@(#)resolu.c 2.2 11/28/91 LBL";
X#endif
X
X/*
X * Read and write image resolutions.
X */
X
X#include <stdio.h>
X
X#include "resolu.h"
X
X
Xchar  resolu_buf[RESOLU_BUFLEN];	/* resolution line buffer */
X
X
Xfputresolu(ord, sl, ns, fp)		/* put out picture dimensions */
Xint  ord;			/* scanline ordering */
Xint  sl, ns;			/* scanline length and number */
XFILE  *fp;
X{
X	RESOLU  rs;
X
X	if ((rs.or = ord) & YMAJOR) {
X		rs.xr = sl;
X		rs.yr = ns;
X	} else {
X		rs.xr = ns;
X		rs.yr = sl;
X	}
X	fputsresolu(&rs, fp);
X}
X
X
Xint
Xfgetresolu(sl, ns, fp)			/* get picture dimensions */
Xint  *sl, *ns;			/* scanline length and number */
XFILE  *fp;
X{
X	RESOLU  rs;
X
X	if (!fgetsresolu(&rs, fp))
X		return(-1);
X	if (rs.or & YMAJOR) {
X		*sl = rs.xr;
X		*ns = rs.yr;
X	} else {
X		*sl = rs.yr;
X		*ns = rs.xr;
X	}
X	return(rs.or);
X}
X
X
Xchar *
Xresolu2str(buf, rp)		/* convert resolution struct to line */
Xchar  *buf;
Xregister RESOLU  *rp;
X{
X	if (rp->or&YMAJOR)
X		sprintf(buf, "%cY %d %cX %d\n",
X				rp->or&YDECR ? '-' : '+', rp->yr,
X				rp->or&XDECR ? '-' : '+', rp->xr);
X	else
X		sprintf(buf, "%cX %d %cY %d\n",
X				rp->or&XDECR ? '-' : '+', rp->xr,
X				rp->or&YDECR ? '-' : '+', rp->yr);
X	return(buf);
X}
X
X
Xstr2resolu(rp, buf)		/* convert resolution line to struct */
Xregister RESOLU  *rp;
Xchar  *buf;
X{
X	register char  *xndx, *yndx;
X	register char  *cp;
X
X	if (buf == NULL)
X		return(0);
X	xndx = yndx = NULL;
X	for (cp = buf; *cp; cp++)
X		if (*cp == 'X')
X			xndx = cp;
X		else if (*cp == 'Y')
X			yndx = cp;
X	if (xndx == NULL || yndx == NULL)
X		return(0);
X	rp->or = 0;
X	if (xndx > yndx) rp->or |= YMAJOR;
X	if (xndx[-1] == '-') rp->or |= XDECR;
X	if (yndx[-1] == '-') rp->or |= YDECR;
X	if ((rp->xr = atoi(xndx+1)) <= 0)
X		return(0);
X	if ((rp->yr = atoi(yndx+1)) <= 0)
X		return(0);
X	return(1);
X}
SHAR_EOF
fi
if test -f 'header.c'
then
	echo shar: "will not over-write existing file 'header.c'"
else
sed 's/^X//' << \SHAR_EOF > 'header.c'
X/* Copyright (c) 1994 Regents of the University of California */
X
X#ifndef lint
Xstatic char SCCSid[] = "@(#)header.c 2.4 2/27/94 LBL";
X#endif
X
X/*
X *  header.c - routines for reading and writing information headers.
X *
X *	8/19/88
X *
X *  newheader(t,fp)	start new information header identified by string t
X *  isheadid(s)		returns true if s is a header id line
X *  headidval(r,s)	copy header identifier value in s to r
X *  printargs(ac,av,fp) print an argument list to fp, followed by '\n'
X *  isformat(s)		returns true if s is of the form "FORMAT=*"
X *  formatval(r,s)	copy the format value in s to r
X *  fputformat(s,fp)	write "FORMAT=%s" to fp
X *  getheader(fp,f,p)	read header from fp, calling f(s,p) on each line
X *  checkheader(i,p,o)	check header format from i against p and copy to o
X *
X *  To copy header from input to output, use getheader(fin, fputs, fout)
X */
X
X#include  <stdio.h>
X#include  <ctype.h>
X
X#define	 MAXLINE	512
X
X#ifndef BSD
X#define	 index	strchr
X#endif
X
Xextern char  *index();
X
Xchar  HDRSTR[] = "#?";		/* information header magic number */
X
Xchar  FMTSTR[] = "FORMAT=";	/* format identifier */
X
X
Xnewheader(s, fp)		/* identifying line of information header */
Xchar  *s;
Xregister FILE  *fp;
X{
X	fputs(HDRSTR, fp);
X	fputs(s, fp);
X	putc('\n', fp);
X}
X
X
Xheadidval(r,s)			/* get header id (return true if is id) */
Xregister char  *r, *s;
X{
X	register char  *cp = HDRSTR;
X
X	while (*cp) if (*cp++ != *s++) return(0);
X	if (r == NULL) return(1);
X	while (*s) *r++ = *s++;
X	*r = '\0';
X	return(1);
X}
X
X
Xisheadid(s)			/* check to see if line is header id */
Xchar  *s;
X{
X	return(headidval(NULL, s));
X}
X
X
Xprintargs(ac, av, fp)		/* print arguments to a file */
Xint  ac;
Xchar  **av;
Xregister FILE  *fp;
X{
X	int  quote;
X
X	while (ac-- > 0) {
X		if (index(*av, ' ') != NULL) {		/* quote it */
X			if (index(*av, '\'') != NULL)
X				quote = '"';
X			else
X				quote = '\'';
X			putc(quote, fp);
X			fputs(*av++, fp);
X			putc(quote, fp);
X		} else
X			fputs(*av++, fp);
X		putc(' ', fp);
X	}
X	putc('\n', fp);
X}
X
X
Xformatval(r, s)			/* get format value (return true if format) */
Xregister char  *r;
Xregister char  *s;
X{
X	register char  *cp = FMTSTR;
X
X	while (*cp) if (*cp++ != *s++) return(0);
X	while (isspace(*s)) s++;
X	if (!*s) return(0);
X	if (r == NULL) return(1);
X	while(*s) *r++ = *s++;
X	while (isspace(r[-1])) r--;
X	*r = '\0';
X	return(1);
X}
X
X
Xisformat(s)			/* is line a format line? */
Xchar  *s;
X{
X	return(formatval(NULL, s));
X}
X
X
Xfputformat(s, fp)		/* put out a format value */
Xchar  *s;
XFILE  *fp;
X{
X	fputs(FMTSTR, fp);
X	fputs(s, fp);
X	putc('\n', fp);
X}
X
X
Xgetheader(fp, f, p)		/* get header from file */
XFILE  *fp;
Xint  (*f)();
Xchar  *p;
X{
X	char  buf[MAXLINE];
X
X	for ( ; ; ) {
X		buf[MAXLINE-2] = '\n';
X		if (fgets(buf, MAXLINE, fp) == NULL)
X			return(-1);
X		if (buf[0] == '\n')
X			return(0);
X#ifdef MSDOS
X		if (buf[0] == '\r' && buf[1] == '\n')
X			return(0);
X#endif
X		if (buf[MAXLINE-2] != '\n') {
X			ungetc(buf[MAXLINE-2], fp);	/* prevent false end */
X			buf[MAXLINE-2] = '\0';
X		}
X		if (f != NULL)
X			(*f)(buf, p);
X	}
X}
X
X
Xstruct check {
X	FILE	*fp;
X	char	fs[64];
X};
X
X
Xstatic
Xmycheck(s, cp)			/* check a header line for format info. */
Xchar  *s;
Xregister struct check  *cp;
X{
X	if (!formatval(cp->fs, s) && cp->fp != NULL)
X		fputs(s, cp->fp);
X}
X
X
X/*
X * Copymatch(pat,str) checks pat for wildcards, and
X * copies str into pat if there is a match (returning true).
X */
X
X#ifdef COPYMATCH
Xcopymatch(pat, str)
Xchar	*pat, *str;
X{
X	int	docopy = 0;
X	register char	*p = pat, *s = str;
X
X	do {
X		switch (*p) {
X		case '?':			/* match any character */
X			if (!*s++)
X				return(0);
X			docopy++;
X			break;
X		case '*':			/* match any string */
X			while (p[1] == '*') p++;
X			do
X				if ( (p[1]=='?' || p[1]==*s)
X						&& copymatch(p+1,s) ) {
X					strcpy(pat, str);
X					return(1);
X				}
X			while (*s++);
X			return(0);
X		case '\\':			/* literal next */
X			p++;
X		/* fall through */
X		default:			/* normal character */
X			if (*p != *s)
X				return(0);
X			s++;
X			break;
X		}
X	} while (*p++);
X	if (docopy)
X		strcpy(pat, str);
X	return(1);
X}
X#else
X#define copymatch(pat, s)	(!strcmp(pat, s))
X#endif
X
X
X/*
X * Checkheader(fin,fmt,fout) returns a value of 1 if the input format
X * matches the specification in fmt, 0 if no input format was found,
X * and -1 if the input format does not match or there is an
X * error reading the header.  If fmt is empty, then -1 is returned
X * if any input format is found (or there is an error), and 0 otherwise.
X * If fmt contains any '*' or '?' characters, then checkheader
X * does wildcard expansion and copies a matching result into fmt.
X * Be sure that fmt is big enough to hold the match in such cases!
X * The input header (minus any format lines) is copied to fout
X * if fout is not NULL.
X */
X
Xcheckheader(fin, fmt, fout)
XFILE  *fin;
Xchar  *fmt;
XFILE  *fout;
X{
X	struct check	cdat;
X
X	cdat.fp = fout;
X	cdat.fs[0] = '\0';
X	if (getheader(fin, mycheck, &cdat) < 0)
X		return(-1);
X	if (cdat.fs[0] != '\0')
X		return(copymatch(fmt, cdat.fs) ? 1 : -1);
X	return(0);
X}
SHAR_EOF
fi
if test -f 'color.c'
then
	echo shar: "will not over-write existing file 'color.c'"
else
sed 's/^X//' << \SHAR_EOF > 'color.c'
X/* Copyright (c) 1991 Regents of the University of California */
X
X#ifndef lint
Xstatic char SCCSid[] = "@(#)color.c 2.8 3/26/94 LBL";
X#endif
X
X/*
X *  color.c - routines for color calculations.
X *
X *     10/10/85
X */
X
X#include  <stdio.h>
X
X#include  <math.h>
X
X#include  "color.h"
X
X#define  MINELEN	8	/* minimum scanline length for encoding */
X#define  MAXELEN	0x7fff	/* maximum scanline length for encoding */
X#define  MINRUN		4	/* minimum run length */
X
X
Xchar *
Xtempbuffer(len)			/* get a temporary buffer */
Xunsigned  len;
X{
X	extern char  *malloc(), *realloc();
X	static char  *tempbuf = NULL;
X	static unsigned  tempbuflen = 0;
X
X	if (len > tempbuflen) {
X		if (tempbuflen > 0)
X			tempbuf = realloc(tempbuf, len);
X		else
X			tempbuf = malloc(len);
X		tempbuflen = tempbuf==NULL ? 0 : len;
X	}
X	return(tempbuf);
X}
X
X
Xfwritecolrs(scanline, len, fp)		/* write out a colr scanline */
Xregister COLR  *scanline;
Xunsigned  len;
Xregister FILE  *fp;
X{
X	register int  i, j, beg, cnt;
X	int  c2;
X	
X	if (len < MINELEN | len > MAXELEN)	/* OOBs, write out flat */
X		return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len);
X					/* put magic header */
X	putc(2, fp);
X	putc(2, fp);
X	putc(len>>8, fp);
X	putc(len&255, fp);
X					/* put components seperately */
X	for (i = 0; i < 4; i++) {
X	    for (j = 0; j < len; j += cnt) {	/* find next run */
X		for (beg = j; beg < len; beg += cnt) {
X		    for (cnt = 1; cnt < 127 && beg+cnt < len &&
X			    scanline[beg+cnt][i] == scanline[beg][i]; cnt++)
X			;
X		    if (cnt >= MINRUN)
X			break;			/* long enough */
X		}
X		if (beg-j > 1 && beg-j < MINRUN) {
X		    c2 = j+1;
X		    while (scanline[c2++][i] == scanline[j][i])
X			if (c2 == beg) {	/* short run */
X			    putc(128+beg-j, fp);
X			    putc(scanline[j][i], fp);
X			    j = beg;
X			    break;
X			}
X		}
X		while (j < beg) {		/* write out non-run */
X		    if ((c2 = beg-j) > 128) c2 = 128;
X		    putc(c2, fp);
X		    while (c2--)
X			putc(scanline[j++][i], fp);
X		}
X		if (cnt >= MINRUN) {		/* write out run */
X		    putc(128+cnt, fp);
X		    putc(scanline[beg][i], fp);
X		} else
X		    cnt = 0;
X	    }
X	}
X	return(ferror(fp) ? -1 : 0);
X}
X
X
Xfreadcolrs(scanline, len, fp)		/* read in an encoded colr scanline */
Xregister COLR  *scanline;
Xint  len;
Xregister FILE  *fp;
X{
X	register int  i, j;
X	int  code, val;
X					/* determine scanline type */
X	if (len < MINELEN | len > MAXELEN)
X		return(oldreadcolrs(scanline, len, fp));
X	if ((i = getc(fp)) == EOF)
X		return(-1);
X	if (i != 2) {
X		ungetc(i, fp);
X		return(oldreadcolrs(scanline, len, fp));
X	}
X	scanline[0][GRN] = getc(fp);
X	scanline[0][BLU] = getc(fp);
X	if ((i = getc(fp)) == EOF)
X		return(-1);
X	if (scanline[0][GRN] != 2 || scanline[0][BLU] & 128) {
X		scanline[0][RED] = 2;
X		scanline[0][EXP] = i;
X		return(oldreadcolrs(scanline+1, len-1, fp));
X	}
X	if ((scanline[0][BLU]<<8 | i) != len)
X		return(-1);		/* length mismatch! */
X					/* read each component */
X	for (i = 0; i < 4; i++)
X	    for (j = 0; j < len; ) {
X		if ((code = getc(fp)) == EOF)
X		    return(-1);
X		if (code > 128) {	/* run */
X		    code &= 127;
X		    val = getc(fp);
X		    while (code--)
X			scanline[j++][i] = val;
X		} else			/* non-run */
X		    while (code--)
X			scanline[j++][i] = getc(fp);
X	    }
X	return(feof(fp) ? -1 : 0);
X}
X
X
Xoldreadcolrs(scanline, len, fp)		/* read in an old colr scanline */
Xregister COLR  *scanline;
Xint  len;
Xregister FILE  *fp;
X{
X	int  rshift;
X	register int  i;
X	
X	rshift = 0;
X	
X	while (len > 0) {
X		scanline[0][RED] = getc(fp);
X		scanline[0][GRN] = getc(fp);
X		scanline[0][BLU] = getc(fp);
X		scanline[0][EXP] = getc(fp);
X		if (feof(fp) || ferror(fp))
X			return(-1);
X		if (scanline[0][RED] == 1 &&
X				scanline[0][GRN] == 1 &&
X				scanline[0][BLU] == 1) {
X			for (i = scanline[0][EXP] << rshift; i > 0; i--) {
X				copycolr(scanline[0], scanline[-1]);
X				scanline++;
X				len--;
X			}
X			rshift += 8;
X		} else {
X			scanline++;
X			len--;
X			rshift = 0;
X		}
X	}
X	return(0);
X}
X
X
Xfwritescan(scanline, len, fp)		/* write out a scanline */
Xregister COLOR  *scanline;
Xint  len;
XFILE  *fp;
X{
X	COLR  *clrscan;
X	int  n;
X	register COLR  *sp;
X					/* get scanline buffer */
X	if ((sp = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
X		return(-1);
X	clrscan = sp;
X					/* convert scanline */
X	n = len;
X	while (n-- > 0) {
X		setcolr(sp[0], scanline[0][RED],
X				  scanline[0][GRN],
X				  scanline[0][BLU]);
X		scanline++;
X		sp++;
X	}
X	return(fwritecolrs(clrscan, len, fp));
X}
X
X
Xfreadscan(scanline, len, fp)		/* read in a scanline */
Xregister COLOR  *scanline;
Xint  len;
XFILE  *fp;
X{
X	register COLR  *clrscan;
X
X	if ((clrscan = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
X		return(-1);
X	if (freadcolrs(clrscan, len, fp) < 0)
X		return(-1);
X					/* convert scanline */
X	colr_color(scanline[0], clrscan[0]);
X	while (--len > 0) {
X		scanline++; clrscan++;
X		if (clrscan[0][RED] == clrscan[-1][RED] &&
X			    clrscan[0][GRN] == clrscan[-1][GRN] &&
X			    clrscan[0][BLU] == clrscan[-1][BLU] &&
X			    clrscan[0][EXP] == clrscan[-1][EXP])
X			copycolor(scanline[0], scanline[-1]);
X		else
X			colr_color(scanline[0], clrscan[0]);
X	}
X	return(0);
X}
X
X
Xsetcolr(clr, r, g, b)		/* assign a short color value */
Xregister COLR  clr;
Xdouble  r, g, b;
X{
X	double  d;
X	int  e;
X	
X	d = r > g ? r : g;
X	if (b > d) d = b;
X
X	if (d <= 1e-32) {
X		clr[RED] = clr[GRN] = clr[BLU] = 0;
X		clr[EXP] = 0;
X		return;
X	}
X
X	d = frexp(d, &e) * 255.9999 / d;
X
X	clr[RED] = r * d;
X	clr[GRN] = g * d;
X	clr[BLU] = b * d;
X	clr[EXP] = e + COLXS;
X}
X
X
Xcolr_color(col, clr)		/* convert short to float color */
Xregister COLOR  col;
Xregister COLR  clr;
X{
X	double  f;
X	
X	if (clr[EXP] == 0)
X		col[RED] = col[GRN] = col[BLU] = 0.0;
X	else {
X		f = ldexp(1.0, (int)clr[EXP]-(COLXS+8));
X		col[RED] = (clr[RED] + 0.5)*f;
X		col[GRN] = (clr[GRN] + 0.5)*f;
X		col[BLU] = (clr[BLU] + 0.5)*f;
X	}
X}
X
X
Xbigdiff(c1, c2, md)			/* c1 delta c2 > md? */
Xregister COLOR  c1, c2;
Xdouble  md;
X{
X	register int  i;
X
X	for (i = 0; i < 3; i++)
X		if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) ||
X			colval(c2,i)-colval(c1,i) > md*colval(c1,i))
X			return(1);
X	return(0);
X}
SHAR_EOF
fi
if test -f 'colrops.c'
then
	echo shar: "will not over-write existing file 'colrops.c'"
else
sed 's/^X//' << \SHAR_EOF > 'colrops.c'
X/* Copyright (c) 1992 Regents of the University of California */
X
X#ifndef lint
Xstatic char SCCSid[] = "@(#)colrops.c 2.4 10/2/92 LBL";
X#endif
X
X/*
X * Integer operations on COLR scanlines
X */
X
X#include "color.h"
X
X#define NULL		0
X
Xextern char	*bmalloc();
X
X#define MAXGSHIFT	31		/* maximum shift for gamma table */
X
Xstatic BYTE	*g_mant = NULL, *g_nexp = NULL;
X
Xstatic BYTE	(*g_bval)[256] = NULL;
X
X#ifndef pow
Xextern double	pow();
X#endif
X
X
Xsetcolrcor(f, a2)		/* set brightness correction */
Xdouble	(*f)();
Xdouble	a2;
X{
X	double	mult;
X	register int	i, j;
X					/* allocate tables */
X	if (g_bval == NULL && (g_bval =
X			(BYTE (*)[256])bmalloc((MAXGSHIFT+1)*256)) == NULL)
X		return(-1);
X					/* compute colr -> gamb mapping */
X	mult = 1.0/256.0;
X	for (i = 0; i <= MAXGSHIFT; i++) {
X		for (j = 0; j < 256; j++)
X			g_bval[i][j] = 256.0 * (*f)((j+.5)*mult, a2);
X		mult *= 0.5;
X	}
X	return(0);
X}
X
X
Xsetcolrinv(f, a2)		/* set inverse brightness correction */
Xdouble	(*f)();
Xdouble	a2;
X{
X	double	mult;
X	register int	i, j;
X					/* allocate tables */
X	if (g_mant == NULL && (g_mant = (BYTE *)bmalloc(256)) == NULL)
X		return(-1);
X	if (g_nexp == NULL && (g_nexp = (BYTE *)bmalloc(256)) == NULL)
X		return(-1);
X					/* compute gamb -> colr mapping */
X	i = 0;
X	mult = 256.0;
X	for (j = 255; j > 0; j--) {
X		while ((g_mant[j] = mult * (*f)(j/256.0, a2)) < 128) {
X			i++;
X			mult *= 2.0;
X		}
X		g_nexp[j] = i;
X	}
X	g_mant[0] = 0;
X	g_nexp[0] = COLXS;
X	return(0);
X}
X
X
Xsetcolrgam(g)			/* set gamma conversion */
Xdouble	g;
X{
X	if (setcolrcor(pow, 1.0/g) < 0)
X		return(-1);
X	return(setcolrinv(pow, g));
X}
X
X
Xcolrs_gambs(scan, len)		/* convert scanline of colrs to gamma bytes */
Xregister COLR	*scan;
Xint	len;
X{
X	register int	i, expo;
X
X	if (g_bval == NULL)
X		return(-1);
X	while (len-- > 0) {
X		expo = scan[0][EXP] - COLXS;
X		if (expo < -MAXGSHIFT) {
X			if (expo < -MAXGSHIFT-8) {
X				scan[0][RED] =
X				scan[0][GRN] =
X				scan[0][BLU] = 0;
X			} else {
X				i = (-MAXGSHIFT-1) - expo;
X				scan[0][RED] = 
X				g_bval[MAXGSHIFT][((scan[0][RED]>>i)+1)>>1];
X				scan[0][GRN] =
X				g_bval[MAXGSHIFT][((scan[0][GRN]>>i)+1)>>1];
X				scan[0][BLU] =
X				g_bval[MAXGSHIFT][((scan[0][BLU]>>i)+1)>>1];
X			}
X		} else if (expo > 0) {
X			if (expo > 8) {
X				scan[0][RED] =
X				scan[0][GRN] =
X				scan[0][BLU] = 255;
X			} else {
X				i = (scan[0][RED]<<1 | 1) << (expo-1);
X				scan[0][RED] = i > 255 ? 255 : g_bval[0][i];
X				i = (scan[0][GRN]<<1 | 1) << (expo-1);
X				scan[0][GRN] = i > 255 ? 255 : g_bval[0][i];
X				i = (scan[0][BLU]<<1 | 1) << (expo-1);
X				scan[0][BLU] = i > 255 ? 255 : g_bval[0][i];
X			}
X		} else {
X			scan[0][RED] = g_bval[-expo][scan[0][RED]];
X			scan[0][GRN] = g_bval[-expo][scan[0][GRN]];
X			scan[0][BLU] = g_bval[-expo][scan[0][BLU]];
X		}
X		scan[0][EXP] = COLXS;
X		scan++;
X	}
X	return(0);
X}
X
X
Xgambs_colrs(scan, len)		/* convert gamma bytes to colr scanline */
Xregister COLR	*scan;
Xint	len;
X{
X	register int	nexpo;
X
X	if (g_mant == NULL | g_nexp == NULL)
X		return(-1);
X	while (len-- > 0) {
X		nexpo = g_nexp[scan[0][RED]];
X		if (g_nexp[scan[0][GRN]] < nexpo)
X			nexpo = g_nexp[scan[0][GRN]];
X		if (g_nexp[scan[0][BLU]] < nexpo)
X			nexpo = g_nexp[scan[0][BLU]];
X		if (nexpo < g_nexp[scan[0][RED]])
X			scan[0][RED] = g_mant[scan[0][RED]]
X					>> (g_nexp[scan[0][RED]]-nexpo);
X		else
X			scan[0][RED] = g_mant[scan[0][RED]];
X		if (nexpo < g_nexp[scan[0][GRN]])
X			scan[0][GRN] = g_mant[scan[0][GRN]]
X					>> (g_nexp[scan[0][GRN]]-nexpo);
X		else
X			scan[0][GRN] = g_mant[scan[0][GRN]];
X		if (nexpo < g_nexp[scan[0][BLU]])
X			scan[0][BLU] = g_mant[scan[0][BLU]]
X					>> (g_nexp[scan[0][BLU]]-nexpo);
X		else
X			scan[0][BLU] = g_mant[scan[0][BLU]];
X		scan[0][EXP] = COLXS - nexpo;
X		scan++;
X	}
X	return(0);
X}
X
X
Xshiftcolrs(scan, len, adjust)	/* shift a scanline of colors by 2^adjust */
Xregister COLR	*scan;
Xregister int	len;
Xregister int	adjust;
X{
X	int	minexp;
X
X	if (adjust == 0)
X		return;
X	minexp = adjust < 0 ? -adjust : 0;
X	while (len-- > 0) {
X		if (scan[0][EXP] <= minexp)
X			scan[0][RED] = scan[0][GRN] = scan[0][BLU] =
X			scan[0][EXP] = 0;
X		else
X			scan[0][EXP] += adjust;
X		scan++;
X	}
X}
X
X
Xnormcolrs(scan, len, adjust)	/* normalize a scanline of colrs */
Xregister COLR  *scan;
Xint  len;
Xint  adjust;
X{
X	register int  c;
X	register int  shift;
X
X	while (len-- > 0) {
X		shift = scan[0][EXP] + adjust - COLXS;
X		if (shift > 0) {
X			if (shift > 8) {
X				scan[0][RED] =
X				scan[0][GRN] =
X				scan[0][BLU] = 255;
X			} else {
X				shift--;
X				c = (scan[0][RED]<<1 | 1) << shift;
X				scan[0][RED] = c > 255 ? 255 : c;
X				c = (scan[0][GRN]<<1 | 1) << shift;
X				scan[0][GRN] = c > 255 ? 255 : c;
X				c = (scan[0][BLU]<<1 | 1) << shift;
X				scan[0][BLU] = c > 255 ? 255 : c;
X			}
X		} else if (shift < 0) {
X			if (shift < -8) {
X				scan[0][RED] =
X				scan[0][GRN] =
X				scan[0][BLU] = 0;
X			} else {
X				shift = -1-shift;
X				scan[0][RED] = ((scan[0][RED]>>shift)+1)>>1;
X				scan[0][GRN] = ((scan[0][GRN]>>shift)+1)>>1;
X				scan[0][BLU] = ((scan[0][BLU]>>shift)+1)>>1;
X			}
X		}
X		scan[0][EXP] = COLXS - adjust;
X		scan++;
X	}
X}
SHAR_EOF
fi
exit 0
#	End of shell archive