--- ray/src/px/macbethcal.c	1995/10/11 10:40:13	2.1
+++ ray/src/px/macbethcal.c	2024/02/22 02:07:40	2.29
@@ -1,145 +1,288 @@
-/* Copyright (c) 1995 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: macbethcal.c,v 2.29 2024/02/22 02:07:40 greg Exp $";
 #endif
-
 /*
  * Calibrate a scanned MacBeth Color Checker Chart
  *
- * Produce a .cal file suitable for use with pcomb.
+ * Produce a .cal file suitable for use with pcomb,
+ * or .cwp file suitable for use with pcwarp.
+ *
+ * Warping code depends on conformance of COLOR and W3VEC types.
  */
 
-#include <stdio.h>
-#ifdef MSDOS
-#include <fcntl.h>
-#endif
+#include <math.h>
+
+#include "platform.h"
+#include "paths.h"
+#include "rtio.h"
 #include "color.h"
 #include "resolu.h"
 #include "pmap.h"
+#include "warp3d.h"
+#include "mx3.h"
 
-				/* MacBeth colors (CIE 1931, absolute white) */
-				/* computed from spectral measurements */
+				/* MacBeth colors */
+#define	DarkSkin	0
+#define	LightSkin	1
+#define	BlueSky		2
+#define	Foliage		3
+#define	BlueFlower	4
+#define	BluishGreen	5
+#define	Orange		6
+#define	PurplishBlue	7
+#define	ModerateRed	8
+#define	Purple		9
+#define	YellowGreen	10
+#define	OrangeYellow	11
+#define	Blue		12
+#define	Green		13
+#define	Red		14
+#define	Yellow		15
+#define	Magenta		16
+#define	Cyan		17
+#define	White		18
+#define	Neutral8	19
+#define	Neutral65	20
+#define	Neutral5	21
+#define	Neutral35	22
+#define	Black		23
+				/* computed from 10nm spectral measurements */
+				/* CIE 1931 2 degree obs, equal-energy white */
 float	mbxyY[24][3] = {
-		{0.462, 0.3769, 0.0932961},	/* DarkSkin */
-		{0.4108, 0.3542, 0.410348},	/* LightSkin */
-		{0.2626, 0.267, 0.181554},	/* BlueSky */
-		{0.36, 0.4689, 0.108447},	/* Foliage */
-		{0.2977, 0.2602, 0.248407},	/* BlueFlower */
-		{0.2719, 0.3485, 0.401156},	/* BluishGreen */
-		{0.52, 0.4197, 0.357899},	/* Orange */
-		{0.229, 0.1866, 0.103911},	/* PurplishBlue */
-		{0.4909, 0.3262, 0.242615},	/* ModerateRed */
-		{0.3361, 0.2249, 0.0600102},	/* Purple */
-		{0.3855, 0.4874, 0.42963},	/* YellowGreen */
-		{0.4853, 0.4457, 0.476343},	/* OrangeYellow */
-		{0.2026, 0.1369, 0.0529249},	/* Blue */
-		{0.3007, 0.4822, 0.221226},	/* Green */
-		{0.5805, 0.3238, 0.162167},	/* Red */
-		{0.4617, 0.472, 0.64909},	/* Yellow */
-		{0.4178, 0.2625, 0.233662},	/* Magenta */
-		{0.2038, 0.2508, 0.167275},	/* Cyan */
-		{0.3358, 0.337, 0.916877},	/* White */
-		{0.3338, 0.3348, 0.604678},	/* Neutral.8 */
-		{0.3333, 0.3349, 0.364566},	/* Neutral.65 */
-		{0.3353, 0.3359, 0.200238},	/* Neutral.5 */
-		{0.3363, 0.336, 0.0878721},	/* Neutral.35 */
-		{0.3346, 0.3349, 0.0308383}	/* Black */
+		{0.421236, 0.361196, 0.103392},		/* DarkSkin */
+		{0.40868, 0.358157, 0.352867},		/* LightSkin */
+		{0.265063, 0.271424, 0.185124},		/* BlueSky */
+		{0.362851, 0.43055, 0.132625},		/* Foliage */
+		{0.28888, 0.260851, 0.233138},		/* BlueFlower */
+		{0.277642, 0.365326, 0.416443},		/* BluishGreen */
+		{0.524965, 0.40068, 0.312039},		/* Orange */
+		{0.225018, 0.190392, 0.114999},		/* PurplishBlue */
+		{0.487199, 0.315372, 0.198616},		/* ModerateRed */
+		{0.314245, 0.227231, 0.0646047},	/* Purple */
+		{0.396202, 0.489732, 0.440724},		/* YellowGreen */
+		{0.493297, 0.435299, 0.43444},		/* OrangeYellow */
+		{0.198191, 0.149265, 0.0588122},	/* Blue */
+		{0.322838, 0.487601, 0.229258},		/* Green */
+		{0.561833, 0.321165, 0.126978},		/* Red */
+		{0.468113, 0.467021, 0.605289},		/* Yellow */
+		{0.397128, 0.248535, 0.201761},		/* Magenta */
+		{0.209552, 0.276256, 0.190917},		/* Cyan */
+		{0.337219, 0.339042, 0.912482},		/* White */
+		{0.333283, 0.335077, 0.588297},		/* Neutral.8 */
+		{0.332747, 0.334371, 0.3594},		/* Neutral.65 */
+		{0.331925, 0.334202, 0.19114},		/* Neutral.5 */
+		{0.330408, 0.332615, 0.0892964},	/* Neutral.35 */
+		{0.331841, 0.331405, 0.0319541},	/* Black */
 	};
 
 COLOR	mbRGB[24];		/* MacBeth RGB values */
 
 #define	NMBNEU		6	/* Number of MacBeth neutral colors */
-short	mbneu[NMBNEU] = {23,22,21,20,19,18};
-#define NMBMOD		3	/* Number of MacBeth moderate colors */
-short	mbmod[NMBMOD] = {1,3,2};
-#define NMBSAT		6	/* Number of MacBeth saturated colors */
-short	mbsat[NMBSAT] = {14,12,13,15,16,17};
+short	mbneu[NMBNEU] = {Black,Neutral35,Neutral5,Neutral65,Neutral8,White};
 
+#define  NEUFLGS	(1L<<White|1L<<Neutral8|1L<<Neutral65| \
+				1L<<Neutral5|1L<<Neutral35|1L<<Black)
+
+#define  SATFLGS	(1L<<Red|1L<<Green|1L<<Blue|1L<<Magenta|1L<<Yellow| \
+			1L<<Cyan|1L<<Orange|1L<<Purple|1L<<PurplishBlue| \
+			1L<<YellowGreen|1<<OrangeYellow|1L<<BlueFlower)
+
+#define  UNSFLGS	(1L<<DarkSkin|1L<<LightSkin|1L<<BlueSky|1L<<Foliage| \
+			1L<<BluishGreen|1L<<ModerateRed)
+
+#define  REQFLGS	NEUFLGS			/* need these colors */
+#define  MODFLGS	(NEUFLGS|UNSFLGS)	/* should be in gamut */
+
+#define  RG_BORD	0	/* patch border */
+#define  RG_CENT	01	/* central region of patch */
+#define  RG_ORIG	02	/* original color region */
+#define  RG_CORR	04	/* corrected color region */
+
+#ifndef  DISPCOM
+#define  DISPCOM	"ximage -e auto -op \"%s\""
+#endif
+
+int	scanning = 1;		/* scanned input (or recorded output)? */
+double	irrad = 1.0;		/* irradiance multiplication factor */
+int	rawmap = 0;		/* put out raw color mapping? */
+
 int	xmax, ymax;		/* input image dimensions */
 int	bounds[4][2];		/* image coordinates of chart corners */
 double	imgxfm[3][3];		/* coordinate transformation matrix */
 
-COLOR	picRGB[24];		/* picture colors */
+COLOR	inpRGB[24];		/* measured or scanned input colors */
+long	inpflags = 0;		/* flags of which colors were input */
+long	gmtflags = 0;		/* flags of out-of-gamut colors */
 
-double	bramp[NMBNEU][2];	/* brightness ramp */
-double	solmat[3][3];		/* color mapping matrix */
+COLOR	bramp[NMBNEU][2];	/* brightness ramp (per primary) */
+COLORMAT	solmat;		/* color mapping matrix */
+COLOR	colmin, colmax;		/* gamut limits */
 
-FILE	*debugfp = NULL;
+WARP3D	*wcor = NULL;		/* color space warp */
+
+FILE	*debugfp = NULL;	/* debug output picture */
 char	*progname;
 
-extern char	*malloc();
+static void init(void);
+static int chartndx(int	x, int y, int	*np);
+static void getpicture(void);
+static void getcolors(void);
+static void bresp(COLOR	y, COLOR	x);
+static void compute(void);
+static void putmapping(void);
+static void compsoln(COLOR	cin[], COLOR	cout[], int	n);
+static void cwarp(void);
+static int cvtcolor(COLOR	cout, COLOR	cin);
+static int cresp(COLOR	cout, COLOR	cin);
+static void xyY2RGB(COLOR	rgbout, float	xyYin[3]);
+static void picdebug(void);
+static void clrdebug(void);
+static void getpos(char	*name, int	bnds[2], FILE	*fp);
+static void pickchartpos(char	*pfn);
 
 
-main(argc, argv)
-int	argc;
-char	**argv;
+int
+main(
+	int	argc,
+	char	**argv
+)
 {
 	int	i;
 
 	progname = argv[0];
-	if (argc > 2 && !strcmp(argv[1], "-d")) {	/* debug output */
-		if ((debugfp = fopen(argv[2], "w")) == NULL) {
-			perror(argv[2]);
-			exit(1);
+	for (i = 1; i < argc && argv[i][0] == '-'; i++)
+		switch (argv[i][1]) {
+		case 'd':				/* debug output */
+			i++;
+			if (badarg(argc-i, argv+i, "s"))
+				goto userr;
+			if ((debugfp = fopen(argv[i], "w")) == NULL) {
+				perror(argv[i]);
+				exit(1);
+			}
+			SET_FILE_BINARY(debugfp);
+			newheader("RADIANCE", debugfp);		/* start */
+			printargs(argc, argv, debugfp);		/* header */
+			break;
+		case 'p':				/* picture position */
+			if (badarg(argc-i-1, argv+i+1, "iiiiiiii"))
+				goto userr;
+			bounds[0][0] = atoi(argv[++i]);
+			bounds[0][1] = atoi(argv[++i]);
+			bounds[1][0] = atoi(argv[++i]);
+			bounds[1][1] = atoi(argv[++i]);
+			bounds[2][0] = atoi(argv[++i]);
+			bounds[2][1] = atoi(argv[++i]);
+			bounds[3][0] = atoi(argv[++i]);
+			bounds[3][1] = atoi(argv[++i]);
+			scanning = 2;
+			break;
+		case 'P':				/* pick position */
+			scanning = 3;
+			break;
+		case 'i':				/* irradiance factor */
+			i++;
+			if (badarg(argc-i, argv+i, "f"))
+				goto userr;
+			irrad = atof(argv[i]);
+			break;
+		case 'm':				/* raw map output */
+			rawmap = 1;
+			break;
+		case 'c':				/* color input */
+			scanning = 0;
+			break;
+		default:
+			goto userr;
 		}
-#ifdef MSDOS
-		setmode(fileno(debugfp), O_BINARY);
-#endif
-		newheader("RADIANCE", debugfp);
-		printargs(argc, argv, debugfp);
-		argv += 2;
-		argc -= 2;
-	}
-	if (argc != 3 && argc != 11)
-		goto userr;
-	if (strcmp(argv[1], "-") && freopen(argv[1], "r", stdin) == NULL) {
-		perror(argv[1]);
+							/* open files */
+	if (i < argc && freopen(argv[i], "r", stdin) == NULL) {
+		perror(argv[i]);
 		exit(1);
 	}
-	if (strcmp(argv[2], "-") && freopen(argv[2], "w", stdout) == NULL) {
-		perror(argv[2]);
+	if (i+1 < argc && freopen(argv[i+1], "w", stdout) == NULL) {
+		perror(argv[i+1]);
 		exit(1);
 	}
-#ifdef MSDOS
-	setmode(fileno(stdin), O_BINARY);
-#endif
-	if (checkheader(stdin, COLRFMT, NULL) < 0 ||
-			fgetresolu(&xmax, &ymax, stdin) < 0) {
-		fprintf(stderr, "%s: bad input picture\n", progname);
-		exit(1);
-	}
-					/* get chart boundaries */
-	if (argc == 11) {
-		for (i = 0; i < 4; i++) {
-			if (!isint(argv[2*i+3]) | !isint(argv[2*i+4]))
+	if (scanning) {			/* load input picture header */
+		SET_FILE_BINARY(stdin);
+		if (checkheader(stdin, COLRFMT, NULL) < 0 ||
+				fgetresolu(&xmax, &ymax, stdin) < 0) {
+			fprintf(stderr, "%s: bad input picture\n", progname);
+			exit(1);
+		}
+		if (scanning == 3) {
+			if (i >= argc)
 				goto userr;
-			bounds[i][0] = atoi(argv[2*i+3]);
-			bounds[i][1] = atoi(argv[2*i+4]);
+			pickchartpos(argv[i]);
+			scanning = 2;
 		}
-	} else {
+	} else {			/* else set default xmax and ymax */
+		xmax = 512;
+		ymax = 2*512/3;
+	}
+	if (scanning != 2) {		/* use default boundaries */
 		bounds[0][0] = bounds[2][0] = .029*xmax + .5;
 		bounds[0][1] = bounds[1][1] = .956*ymax + .5;
 		bounds[1][0] = bounds[3][0] = .971*xmax + .5;
 		bounds[2][1] = bounds[3][1] = .056*ymax + .5;
 	}
 	init();				/* initialize */
-	getcolors();			/* get picture colors */
-	putmapping();			/* put out color mapping */
-	putdebug();			/* put out debug picture */
+	if (scanning)			/* get picture colors */
+		getpicture();
+	else
+		getcolors();
+	compute();			/* compute color mapping */
+	if (rawmap) {			/* print out raw correspondence */
+		int	j;
+
+		printf("# Color correspondence produced by:\n#\t\t");
+		printargs(argc, argv, stdout);
+		printf("#\tUsage: pcwarp %s uncorrected.hdr > corrected.hdr\n",
+				i+1 < argc ? argv[i+1] : "{this_file}");
+		printf("#\t   Or: pcond [options] -m %s orig.hdr > output.hdr\n",
+				i+1 < argc ? argv[i+1] : "{this_file}");
+		for (j = 0; j < 24; j++)
+			printf("%f %f %f    %f %f %f\n",
+				colval(inpRGB[j],RED), colval(inpRGB[j],GRN),
+				colval(inpRGB[j],BLU), colval(mbRGB[j],RED),
+				colval(mbRGB[j],GRN), colval(mbRGB[j],BLU));
+		if (scanning && debugfp != NULL)
+			cwarp();		/* color warp for debugging */
+	} else {			/* print color mapping */
+						/* print header */
+		printf("{\n\tColor correction file computed by:\n\t\t");
+		printargs(argc, argv, stdout);
+		printf("\n\tUsage: pcomb -f %s uncorrected.hdr > corrected.hdr\n",
+				i+1 < argc ? argv[i+1] : "{this_file}");
+		if (!scanning)
+			printf("\t   Or: pcond [options] -f %s orig.hdr > output.hdr\n",
+					i+1 < argc ? argv[i+1] : "{this_file}");
+		printf("}\n");
+		putmapping();			/* put out color mapping */
+	}
+	if (debugfp != NULL) {		/* put out debug picture */
+		if (scanning)
+			picdebug();
+		else
+			clrdebug();
+	}
 	exit(0);
 userr:
-	fprintf(stderr, "Usage: %s [-d dbg.pic] input.pic output.cal [xul yul xur yur xll yll xlr ylr]\n",
+	fprintf(stderr,
+"Usage: %s [-d dbg.hdr][-P | -p xul yul xur yur xll yll xlr ylr][-i irrad][-m] input.hdr [output.{cal|cwp}]\n",
 			progname);
+	fprintf(stderr, "   or: %s [-d dbg.hdr][-i irrad][-m] -c [xyY.dat [output.{cal|cwp}]]\n",
+			progname);
 	exit(1);
+	return 1; /* pro forma return */
 }
 
 
-init()				/* initialize */
+static void
+init(void)				/* initialize */
 {
 	double	quad[4][2];
-	COLOR	ctmp;
-	double	d;
 	int	i;
 					/* make coordinate transformation */
 	quad[0][0] = bounds[0][0];
@@ -157,18 +300,18 @@ init()				/* initialize */
 	}
 					/* map MacBeth colors to RGB space */
 	for (i = 0; i < 24; i++) {
-		d = mbxyY[i][2] / mbxyY[i][1];
-		ctmp[0] = mbxyY[i][0] * d;
-		ctmp[1] = mbxyY[i][2];
-		ctmp[2] = (1. - mbxyY[i][0] - mbxyY[i][1]) * d;
-		cie_rgb(mbRGB[i], ctmp);
+		xyY2RGB(mbRGB[i], mbxyY[i]);
+		scalecolor(mbRGB[i], irrad);
 	}
 }
 
 
-int
-chartndx(x, y)				/* find color number for position */
-int	x, y;
+static int
+chartndx(			/* find color number for position */
+	int	x,
+	int y,
+	int	*np
+)
 {
 	double	ipos[3], cpos[3];
 	int	ix, iy;
@@ -180,26 +323,32 @@ int	x, y;
 	mx3d_transform(ipos, imgxfm, cpos);
 	cpos[0] /= cpos[2];
 	cpos[1] /= cpos[2];
-	if (cpos[0] < 0. || cpos[0] >= 6. || cpos[1] < 0. || cpos[1] >= 4.)
-		return(-1);
+	if ((cpos[0] < 0.) | (cpos[0] >= 6.) | (cpos[1] < 0.) | (cpos[1] >= 4.))
+		return(RG_BORD);
 	ix = cpos[0];
 	iy = cpos[1];
 	fx = cpos[0] - ix;
 	fy = cpos[1] - iy;
-	if (fx < .35 || fx >= .65 || fy < .35 || fy >= .65)
-		return(-1);
-	return(iy*6 + ix);
+	*np = iy*6 + ix;
+	if ((fx >= 0.35) & (fx < 0.65) & (fy >= 0.35) & (fy < 0.65))
+		return(RG_CENT);
+	if ((fx < 0.05) | (fx >= 0.95) | (fy < 0.05) | (fy >= 0.95))
+		return(RG_BORD);
+	if (fx >= 0.5)			/* right side is corrected */
+		return(RG_CORR);
+	return(RG_ORIG);		/* left side is original */
 }
 
 
-getcolors()				/* load in picture colors */
+static void
+getpicture(void)				/* load in picture colors */
 {
 	COLR	*scanln;
 	COLOR	pval;
 	int	ccount[24];
 	double	d;
-	int	y;
-	register int	x, i;
+	int	y, i;
+	int	x;
 
 	scanln = (COLR *)malloc(xmax*sizeof(COLR));
 	if (scanln == NULL) {
@@ -207,7 +356,7 @@ getcolors()				/* load in picture colors */
 		exit(1);
 	}
 	for (i = 0; i < 24; i++) {
-		setcolor(picRGB[i], 0., 0., 0.);
+		setcolor(inpRGB[i], 0., 0., 0.);
 		ccount[i] = 0;
 	}
 	for (y = ymax-1; y >= 0; y--) {
@@ -216,101 +365,241 @@ getcolors()				/* load in picture colors */
 					progname);
 			exit(1);
 		}
-		for (x = 0; x < xmax; x++) {
-			i = chartndx(x, y);
-			if (i >= 0) {
+		for (x = 0; x < xmax; x++)
+			if (chartndx(x, y, &i) == RG_CENT) {
 				colr_color(pval, scanln[x]);
-				addcolor(picRGB[i], pval);
+				addcolor(inpRGB[i], pval);
 				ccount[i]++;
 			}
+	}
+	for (i = 0; i < 24; i++) {		/* compute averages */
+		if (ccount[i] == 0)
+			continue;
+		d = 1./ccount[i];
+		scalecolor(inpRGB[i], d);
+		inpflags |= 1L<<i;
+	}
+	free((void *)scanln);
+}
+
+
+static void
+getcolors(void)			/* get xyY colors from standard input */
+{
+	int	gotwhite = 0;
+	COLOR	whiteclr;
+	int	n;
+	float	xyYin[3];
+
+	while (fgetval(stdin, 'i', &n) == 1) {		/* read colors */
+		if ((n < 0) | (n > 24) ||
+				fgetval(stdin, 'f', &xyYin[0]) != 1 ||
+				fgetval(stdin, 'f', &xyYin[1]) != 1 ||
+				fgetval(stdin, 'f', &xyYin[2]) != 1 ||
+				(xyYin[0] < 0.) | (xyYin[1] < 0.) ||
+				xyYin[0] + xyYin[1] > 1.) {
+			fprintf(stderr, "%s: bad color input data\n",
+					progname);
+			exit(1);
 		}
+		if (n == 0) {				/* calibration white */
+			xyY2RGB(whiteclr, xyYin);
+			gotwhite++;
+		} else {				/* standard color */
+			n--;
+			xyY2RGB(inpRGB[n], xyYin);
+			inpflags |= 1L<<n;
+		}
 	}
-	for (i = 0; i < 24; i++) {
-		if (ccount[i] == 0) {
-			fprintf(stderr, "%s: bad chart boundaries\n",
+					/* normalize colors */
+	if (!gotwhite) {
+		if (!(inpflags & 1L<<White)) {
+			fprintf(stderr, "%s: missing input for White\n",
 					progname);
 			exit(1);
 		}
-		d = 1.0/ccount[i];
-		scalecolor(picRGB[i], d);
+		setcolor(whiteclr,
+			colval(inpRGB[White],RED)/colval(mbRGB[White],RED),
+			colval(inpRGB[White],GRN)/colval(mbRGB[White],GRN),
+			colval(inpRGB[White],BLU)/colval(mbRGB[White],BLU));
 	}
-	free((char *)scanln);
+	for (n = 0; n < 24; n++)
+		if (inpflags & 1L<<n)
+			setcolor(inpRGB[n],
+				colval(inpRGB[n],RED)/colval(whiteclr,RED),
+				colval(inpRGB[n],GRN)/colval(whiteclr,GRN),
+				colval(inpRGB[n],BLU)/colval(whiteclr,BLU));
 }
 
 
-double
-bresp(x)		/* piecewise linear interpolation of brightness */
-double	x;
+static void
+bresp(		/* piecewise linear interpolation of primaries */
+	COLOR	y,
+	COLOR	x
+)
 {
-	register int	n = NMBNEU;
+	int	i, n;
 
-	while (n > 0 && x < bramp[--n][0])
-		;
-	return( ((bramp[n+1][0] - x)*bramp[n][1] +
-				(x - bramp[n][0])*bramp[n+1][1]) /
-			(bramp[n+1][0] - bramp[n][0]) );
+	for (i = 0; i < 3; i++) {
+		for (n = 0; n < NMBNEU-2; n++)
+			if (colval(x,i) < colval(bramp[n+1][0],i))
+				break;
+		colval(y,i) = ((colval(bramp[n+1][0],i) - colval(x,i)) *
+						colval(bramp[n][1],i) +
+				(colval(x,i) - colval(bramp[n][0],i)) *
+						colval(bramp[n+1][1],i)) /
+			(colval(bramp[n+1][0],i) - colval(bramp[n][0],i));
+	}
 }
 
 
-putmapping()			/* compute and print mapping for pcomb -f */
+static void
+compute(void)			/* compute color mapping */
 {
-	float	clrin[NMBMOD][3], clrout[NMBMOD][3];
-	register int	i, j;
+	COLOR	clrin[24], clrout[24];
+	long	cflags;
+	COLOR	ctmp;
+	int	i, n;
+					/* did we get what we need? */
+	if ((inpflags & REQFLGS) != REQFLGS) {
+		fprintf(stderr, "%s: missing required input colors\n",
+				progname);
+		exit(1);
+	}
 					/* compute piecewise luminance curve */
 	for (i = 0; i < NMBNEU; i++) {
-		bramp[i][0] = bright(picRGB[mbneu[i]]);
-		bramp[i][1] = bright(mbRGB[mbneu[i]]);
+		copycolor(bramp[i][0], inpRGB[mbneu[i]]);
+		for (n = 3*(i>0); n--; )
+			if (colval(bramp[i][0],n) <=
+					colval(bramp[i-1][0],n)+1e-7) {
+				fprintf(stderr,
+		"%s: non-increasing neutral patch\n", progname);
+				exit(1);
+			}
+		copycolor(bramp[i][1], mbRGB[mbneu[i]]);
 	}
-					/* compute color matrix */
-	for (i = 0; i < NMBMOD; i++)
-		for (j = 0; j < 3; j++) {
-			clrin[i][j] = bresp(picRGB[mbmod[i]][j]);
-			clrout[i][j] = mbRGB[mbmod[i]][j];
+					/* compute color space gamut */
+	if (scanning) {
+		copycolor(colmin, cblack);
+		copycolor(colmax, cwhite);
+		scalecolor(colmax, irrad);
+	} else
+		for (i = 0; i < 3; i++) {
+			colval(colmin,i) = colval(bramp[0][0],i) -
+				colval(bramp[0][1],i) *
+				(colval(bramp[1][0],i)-colval(bramp[0][0],i)) /
+				(colval(bramp[1][1],i)-colval(bramp[0][1],i));
+			colval(colmax,i) = colval(bramp[NMBNEU-2][0],i) +
+				(1.-colval(bramp[NMBNEU-2][1],i)) *
+				(colval(bramp[NMBNEU-1][0],i) -
+					colval(bramp[NMBNEU-2][0],i)) /
+				(colval(bramp[NMBNEU-1][1],i) -
+					colval(bramp[NMBNEU-2][1],i));
 		}
-	compsoln(clrin, clrout, NMBMOD);
+					/* compute color mapping */
+	do {
+		cflags = inpflags & ~gmtflags;
+		n = 0;				/* compute transform matrix */
+		for (i = 0; i < 24; i++)
+			if (cflags & 1L<<i) {
+				bresp(clrin[n], inpRGB[i]);
+				copycolor(clrout[n], mbRGB[i]);
+				n++;
+			}
+		compsoln(clrin, clrout, n);
+		for (i = 0; i < 24; i++)	/* check gamut */
+			if (cflags & 1L<<i && cvtcolor(ctmp, inpRGB[i]))
+				gmtflags |= 1L<<i;
+	} while (cflags & gmtflags);
+	if (gmtflags & MODFLGS)
+		fprintf(stderr,
+		"%s: warning - some moderate colors are out of gamut\n",
+				progname);
+}
+
+
+static void
+putmapping(void)			/* put out color mapping */
+{
+	static char	cchar[3] = {'r', 'g', 'b'};
+	int	i, j;
 					/* print brightness mapping */
-	printf("xval(i) : select(i, 0");
-	for (i = 0; i < NMBNEU; i++)
-		printf(", %g", bramp[i][0]);
-	printf(");\n");
-	printf("yval(i) : select(i, 0");
-	for (i = 0; i < NMBNEU; i++)
-		printf(", %g", bramp[i][1]);
-	printf(");\n");
-	printf("ifind(x,f,n) : if(1.5-n, 1, if(x-f(n), n, ifind(x,f,n-1)));\n");
-	printf("binterp(i,x) : ((xval(i+1)-x)*yval(i) + (x-xval(i))*yval(i+1))/\n");
-	printf("\t\t(xval(i+1) - xval(i));\n");
-	printf("bresp(x) : binterp(ifind(x,xval,xval(0)-1), x);\n");
-	printf("nred = bresp(ri(1));\n");
-	printf("ngrn = bresp(gi(1));\n");
-	printf("nblu = bresp(bi(1));\n");
+	for (j = 0; j < 3; j++) {
+		printf("%cxa(i) : select(i", cchar[j]);
+		for (i = 0; i < NMBNEU; i++)
+			printf(",%g", colval(bramp[i][0],j));
+		printf(");\n");
+		printf("%cya(i) : select(i", cchar[j]);
+		for (i = 0; i < NMBNEU; i++)
+			printf(",%g", colval(bramp[i][1],j));
+		printf(");\n");
+		printf("%cfi(n) = if(n-%g, %d, if(%cxa(n+1)-%c, n, %cfi(n+1)));\n",
+				cchar[j], NMBNEU-1.5, NMBNEU-1, cchar[j],
+				cchar[j], cchar[j]);
+		printf("%cndx = %cfi(1);\n", cchar[j], cchar[j]);
+		printf("%c%c = ((%cxa(%cndx+1)-%c)*%cya(%cndx) + ",
+				cchar[j], scanning?'n':'o', cchar[j],
+				cchar[j], cchar[j], cchar[j], cchar[j]);
+		printf("(%c-%cxa(%cndx))*%cya(%cndx+1)) /\n",
+				cchar[j], cchar[j], cchar[j],
+				cchar[j], cchar[j]);
+		printf("\t\t(%cxa(%cndx+1) - %cxa(%cndx)) ;\n",
+				cchar[j], cchar[j], cchar[j], cchar[j]);
+	}
 					/* print color mapping */
-	printf("ro = %g*nred + %g*ngrn + %g*nblu\n",
-			solmat[0][0], solmat[1][0], solmat[2][0]);
-	printf("go = %g*nred + %g*ngrn + %g*nblu\n",
-			solmat[0][1], solmat[1][1], solmat[2][1]);
-	printf("bo = %g*nred + %g*ngrn + %g*nblu\n",
-			solmat[0][2], solmat[1][2], solmat[2][2]);
+	if (scanning) {
+		printf("r = ri(1); g = gi(1); b = bi(1);\n");
+		printf("ro = %g*rn + %g*gn + %g*bn ;\n",
+				solmat[0][0], solmat[0][1], solmat[0][2]);
+		printf("go = %g*rn + %g*gn + %g*bn ;\n",
+				solmat[1][0], solmat[1][1], solmat[1][2]);
+		printf("bo = %g*rn + %g*gn + %g*bn ;\n",
+				solmat[2][0], solmat[2][1], solmat[2][2]);
+	} else {
+		printf("r1 = ri(1); g1 = gi(1); b1 = bi(1);\n");
+		printf("r = %g*r1 + %g*g1 + %g*b1 ;\n",
+				solmat[0][0], solmat[0][1], solmat[0][2]);
+		printf("g = %g*r1 + %g*g1 + %g*b1 ;\n",
+				solmat[1][0], solmat[1][1], solmat[1][2]);
+		printf("b = %g*r1 + %g*g1 + %g*b1 ;\n",
+				solmat[2][0], solmat[2][1], solmat[2][2]);
+	}
 }
 
 
-compsoln(cin, cout, n)		/* solve 3x3 system */
-float	cin[][3], cout[][3];
-int	n;
+static void
+compsoln(		/* solve 3xN system using least-squares */
+	COLOR	cin[],
+	COLOR	cout[],
+	int	n
+)
 {
 	extern double	mx3d_adjoint(), fabs();
 	double	mat[3][3], invmat[3][3];
 	double	det;
 	double	colv[3], rowv[3];
-	register int	i, j;
+	int	i, j, k;
 
-	if (n != 3) {
-		fprintf(stderr, "%s: inconsistent code!\n", progname);
+	if (n < 3) {
+		fprintf(stderr, "%s: too few colors to match!\n", progname);
 		exit(1);
 	}
-	for (i = 0; i < 3; i++)
-		for (j = 0; j < 3; j++)
-			mat[i][j] = cin[j][i];
+	if (n == 3)
+		for (i = 0; i < 3; i++)
+			for (j = 0; j < 3; j++)
+				mat[i][j] = colval(cin[j],i);
+	else {				/* compute A^t A */
+		for (i = 0; i < 3; i++)
+			for (j = i; j < 3; j++) {
+				mat[i][j] = 0.;
+				for (k = 0; k < n; k++)
+					mat[i][j] += colval(cin[k],i) *
+							colval(cin[k],j);
+			}
+		for (i = 1; i < 3; i++)		/* using symmetry */
+			for (j = 0; j < i; j++)
+				mat[i][j] = mat[j][i];
+	}
 	det = mx3d_adjoint(mat, invmat);
 	if (fabs(det) < 1e-4) {
 		fprintf(stderr, "%s: cannot compute color mapping\n",
@@ -324,42 +613,100 @@ int	n;
 		for (j = 0; j < 3; j++)
 			invmat[i][j] /= det;
 	for (i = 0; i < 3; i++) {
+		if (n == 3)
+			for (j = 0; j < 3; j++)
+				colv[j] = colval(cout[j],i);
+		else
+			for (j = 0; j < 3; j++) {
+				colv[j] = 0.;
+				for (k = 0; k < n; k++)
+					colv[j] += colval(cout[k],i) *
+							colval(cin[k],j);
+			}
+		mx3d_transform(colv, invmat, rowv);
 		for (j = 0; j < 3; j++)
-			rowv[j] = cout[j][i];
-		mx3d_transform(rowv, invmat, colv);
-		for (j = 0; j < 3; j++)
-			solmat[j][i] = colv[j];
+			solmat[i][j] = rowv[j];
 	}
 }
 
 
-cvtcolor(cout, cin)		/* convert color according to our mapping */
-COLOR	cout, cin;
+static void
+cwarp(void)				/* compute color warp map */
 {
-	double	r, g, b;
-	double	r1, g1, b1;
+	int	i;
 
-	r = bresp(colval(cin,RED));
-	g = bresp(colval(cin,GRN));
-	b = bresp(colval(cin,BLU));
-	r1 = r*solmat[0][0] + g*solmat[1][0] + b*solmat[2][0];
-	if (r1 < 0) r1 = 0;
-	g1 = r*solmat[0][1] + g*solmat[1][1] + b*solmat[2][1];
-	if (g1 < 0) g1 = 0;
-	b1 = r*solmat[0][2] + g*solmat[1][2] + b*solmat[2][2];
-	if (b1 < 0) b1 = 0;
-	setcolor(cout, r1, g1, b1);
+	if ((wcor = new3dw(W3EXACT)) == NULL)
+		goto memerr;
+	for (i = 0; i < 24; i++)
+		if (!add3dpt(wcor, inpRGB[i], mbRGB[i]))
+			goto memerr;
+	return;
+memerr:
+	perror(progname);
+	exit(1);
 }
 
 
-putdebug()			/* put out debugging picture */
+static int
+cvtcolor(		/* convert color according to our mapping */
+	COLOR	cout,
+	COLOR	cin
+)
 {
+	COLOR	ctmp;
+	int	clipped;
+
+	if (wcor != NULL) {
+		clipped = warp3d(cout, cin, wcor);
+		clipped |= clipgamut(cout,bright(cout),CGAMUT,colmin,colmax);
+	} else if (scanning) {
+		bresp(ctmp, cin);
+		clipped = cresp(cout, ctmp);
+	} else {
+		clipped = cresp(ctmp, cin);
+		bresp(cout, ctmp);
+	}
+	return(clipped);
+}
+
+
+static int
+cresp(		/* transform color according to matrix */
+	COLOR	cout,
+	COLOR	cin
+)
+{
+	colortrans(cout, solmat, cin);
+	return(clipgamut(cout, bright(cout), CGAMUT, colmin, colmax));
+}
+
+
+static void
+xyY2RGB(		/* convert xyY to RGB */
+	COLOR	rgbout,
+	float	xyYin[3]
+)
+{
+	COLOR	ctmp;
+	double	d;
+
+	d = xyYin[2] / xyYin[1];
+	ctmp[0] = xyYin[0] * d;
+	ctmp[1] = xyYin[2];
+	ctmp[2] = (1. - xyYin[0] - xyYin[1]) * d;
+				/* allow negative values */
+	colortrans(rgbout, xyz2rgbmat, ctmp);
+}
+
+
+static void
+picdebug(void)			/* put out debugging picture */
+{
+	static COLOR	blkcol = BLKCOLOR;
 	COLOR	*scan;
-	int	y;
-	register int	x, i;
+	int	y, i;
+	int	x, rg;
 
-	if (debugfp == NULL)
-		return;
 	if (fseek(stdin, 0L, 0) == EOF) {
 		fprintf(stderr, "%s: cannot seek on input picture\n", progname);
 		exit(1);
@@ -373,8 +720,10 @@ putdebug()			/* put out debugging picture */
 		exit(1);
 	}
 						/* finish debug header */
+	fputformat(COLRFMT, debugfp);
 	putc('\n', debugfp);
 	fprtresolu(xmax, ymax, debugfp);
+						/* write debug picture */
 	for (y = ymax-1; y >= 0; y--) {
 		if (freadscan(scan, xmax, stdin) < 0) {
 			fprintf(stderr, "%s: error rereading input picture\n",
@@ -382,11 +731,18 @@ putdebug()			/* put out debugging picture */
 			exit(1);
 		}
 		for (x = 0; x < xmax; x++) {
-			i = chartndx(x, y);
-			if (i < 0)
+			rg = chartndx(x, y, &i);
+			if (rg == RG_CENT) {
+				if (!(1L<<i & gmtflags) || (x+y)&07) {
+					copycolor(scan[x], mbRGB[i]);
+					clipgamut(scan[x], bright(scan[x]),
+						CGAMUT, colmin, colmax);
+				} else
+					copycolor(scan[x], blkcol);
+			} else if (rg == RG_CORR)
 				cvtcolor(scan[x], scan[x]);
-			else
-				copycolor(scan[x], mbRGB[i]);
+			else if (rg != RG_ORIG)
+				copycolor(scan[x], blkcol);
 		}
 		if (fwritescan(scan, xmax, debugfp) < 0) {
 			fprintf(stderr, "%s: error writing debugging picture\n",
@@ -394,5 +750,120 @@ putdebug()			/* put out debugging picture */
 			exit(1);
 		}
 	}
-	free((char *)scan);
+						/* clean up */
+	fclose(debugfp);
+	free((void *)scan);
+}
+
+
+static void
+clrdebug(void)			/* put out debug picture from color input */
+{
+	static COLR	blkclr = BLKCOLR;
+	COLR	mbclr[24], cvclr[24], orclr[24];
+	COLR	*scan;
+	COLOR	ctmp, ct2;
+	int	y, i;
+	int	x, rg;
+						/* convert colors */
+	for (i = 0; i < 24; i++) {
+		copycolor(ctmp, mbRGB[i]);
+		clipgamut(ctmp, bright(ctmp), CGAMUT, cblack, cwhite);
+		setcolr(mbclr[i], colval(ctmp,RED),
+				colval(ctmp,GRN), colval(ctmp,BLU));
+		if (inpflags & 1L<<i) {
+			copycolor(ctmp, inpRGB[i]);
+			clipgamut(ctmp, bright(ctmp), CGAMUT, cblack, cwhite);
+			setcolr(orclr[i], colval(ctmp,RED),
+					colval(ctmp,GRN), colval(ctmp,BLU));
+			if (rawmap)
+				copycolr(cvclr[i], mbclr[i]);
+			else {
+				bresp(ctmp, inpRGB[i]);
+				colortrans(ct2, solmat, ctmp);
+				clipgamut(ct2, bright(ct2), CGAMUT,
+						cblack, cwhite);
+				setcolr(cvclr[i], colval(ct2,RED),
+						colval(ct2,GRN),
+						colval(ct2,BLU));
+			}
+		}
+	}
+						/* allocate scanline */
+	scan = (COLR *)malloc(xmax*sizeof(COLR));
+	if (scan == NULL) {
+		perror(progname);
+		exit(1);
+	}
+						/* finish debug header */
+	fputformat(COLRFMT, debugfp);
+	putc('\n', debugfp);
+	fprtresolu(xmax, ymax, debugfp);
+						/* write debug picture */
+	for (y = ymax-1; y >= 0; y--) {
+		for (x = 0; x < xmax; x++) {
+			rg = chartndx(x, y, &i);
+			if (rg == RG_CENT) {
+				if (!(1L<<i & gmtflags) || (x+y)&07)
+					copycolr(scan[x], mbclr[i]);
+				else
+					copycolr(scan[x], blkclr);
+			} else if (rg == RG_BORD || !(1L<<i & inpflags))
+				copycolr(scan[x], blkclr);
+			else if (rg == RG_ORIG)
+				copycolr(scan[x], orclr[i]);
+			else /* rg == RG_CORR */
+				copycolr(scan[x], cvclr[i]);
+		}
+		if (fwritecolrs(scan, xmax, debugfp) < 0) {
+			fprintf(stderr, "%s: error writing debugging picture\n",
+					progname);
+			exit(1);
+		}
+	}
+						/* clean up */
+	fclose(debugfp);
+	free((void *)scan);
+}
+
+
+static void
+getpos(		/* get boundary position */
+	char	*name,
+	int	bnds[2],
+	FILE	*fp
+)
+{
+	char	buf[64];
+
+	fprintf(stderr, "\tSelect corner: %s\n", name);
+	if (fgets(buf, sizeof(buf), fp) == NULL ||
+			sscanf(buf, "%d %d", &bnds[0], &bnds[1]) != 2) {
+		fprintf(stderr, "%s: read error from display process\n",
+				progname);
+		exit(1);
+	}
+}
+
+
+static void
+pickchartpos(		/* display picture and pick chart location */
+	char	*pfn
+)
+{
+	char	combuf[PATH_MAX];
+	FILE	*pfp;
+
+	sprintf(combuf, DISPCOM, pfn);
+	if ((pfp = popen(combuf, "r")) == NULL) {
+		perror(combuf);
+		exit(1);
+	}
+	fputs("Use middle mouse button to select chart corners:\n", stderr);
+	getpos("upper left (dark skin)", bounds[0], pfp);
+	getpos("upper right (bluish green)", bounds[1], pfp);
+	getpos("lower left (white)", bounds[2], pfp);
+	getpos("lower right (black)", bounds[3], pfp);
+	fputs("Got it -- quit display program.\n", stderr);
+	pclose(pfp);
 }