--- ray/src/px/pcomb.c	1991/04/18 10:19:48	1.9
+++ ray/src/px/pcomb.c	1991/04/23 15:49:53	1.12
@@ -48,27 +48,32 @@ int	xres=0, yres=0;			/* picture resolution */
 
 int	xpos, ypos;			/* picture position */
 
+int	wrongformat = 0;
 
+
 tputs(s)			/* put out string preceded by a tab */
 char	*s;
 {
+	char	fmt[32];
 	double	d;
 	COLOR	ctmp;
-				/* echo header line */
-	putchar('\t');
-	fputs(s, stdout);
-	if (!original)
-		return;
-				/* check for exposure */
-	if (isexpos(s)) {
+
+	if (isformat(s)) {			/* check format */
+		formatval(fmt, s);
+		wrongformat = strcmp(fmt, COLRFMT);
+	} else if (original && isexpos(s)) {	/* exposure */
 		d = 1.0/exposval(s);
 		scalecolor(input[nfiles].coef, d);
-	} else if (iscolcor(s)) {
+	} else if (original && iscolcor(s)) {	/* color correction */
 		colcorval(ctmp, s);
 		colval(input[nfiles].coef,RED) /= colval(ctmp,RED);
 		colval(input[nfiles].coef,GRN) /= colval(ctmp,GRN);
 		colval(input[nfiles].coef,BLU) /= colval(ctmp,BLU);
+	} else {				/* echo unaffected line */
+		putchar('\t');
+		fputs(s, stdout);
 	}
+
 }
 
 
@@ -80,10 +85,10 @@ char	*argv[];
 	double	f;
 	int	a;
 	
-	funset(vcolin[RED], 1, l_redin);
-	funset(vcolin[GRN], 1, l_grnin);
-	funset(vcolin[BLU], 1, l_bluin);
-	funset(vbrtin, 1, l_brtin);
+	funset(vcolin[RED], 1, '=', l_redin);
+	funset(vcolin[GRN], 1, '=', l_grnin);
+	funset(vcolin[BLU], 1, '=', l_bluin);
+	funset(vbrtin, 1, '=', l_brtin);
 	
 	for (a = 1; a < argc; a++)
 		if (argv[a][0] == '-')
@@ -153,7 +158,12 @@ getfiles:
 		}
 		fputs(input[nfiles].name, stdout);
 		fputs(":\n", stdout);
-		getheader(input[nfiles].fp, tputs);
+		getheader(input[nfiles].fp, tputs, NULL);
+		if (wrongformat) {
+			eputs(input[nfiles].name);
+			eputs(": not in Radiance picture format\n");
+			quit(1);
+		}
 		if (fgetresolu(&xpos, &ypos, input[nfiles].fp) !=
 				(YMAJOR|YDECR)) {
 			eputs(input[nfiles].name);
@@ -172,6 +182,7 @@ getfiles:
 		nfiles++;
 	}
 	printargs(argc, argv, stdout);
+	fputformat(COLRFMT, stdout);
 	putchar('\n');
 	fputresolu(YMAJOR|YDECR, xres, yres, stdout);
 	combine();
@@ -203,9 +214,9 @@ combine()			/* combine pictures */
 	else
 		brtdef = NULL;
 						/* predefine variables */
-	varset(vnfiles, (double)nfiles);
-	varset(vxres, (double)xres);
-	varset(vyres, (double)yres);
+	varset(vnfiles, '=', (double)nfiles);
+	varset(vxres, '=', (double)xres);
+	varset(vyres, '=', (double)yres);
 						/* allocate scanline */
 	scanout = (COLOR *)emalloc(xres*sizeof(COLOR));
 						/* combine files */
@@ -216,11 +227,11 @@ combine()			/* combine pictures */
 			    eputs(": read error\n");
 			    quit(1);
 		    }
-	    varset(vypos, (double)ypos);
+	    varset(vypos, '=', (double)ypos);
 	    for (xpos = 0; xpos < xres; xpos++) {
 		for (i = 0; i < nfiles; i++)
 			multcolor(input[i].scan[xpos],input[i].coef);
-		varset(vxpos, (double)xpos);
+		varset(vxpos, '=', (double)xpos);
 		eclock++;
 		if (brtdef != NULL) {
 		    d = evalue(brtdef);