--- ray/src/px/pfilt.c	1990/12/08 10:14:33	1.13
+++ ray/src/px/pfilt.c	1991/06/05 12:15:30	1.17
@@ -19,6 +19,8 @@ static char SCCSid[] = "$SunId$ LBL";
 extern char  *malloc();
 extern float  *matchlamp();
 
+#define  FEQ(a,b)	((a) >= .98*(b) && (a) <= 1.02*(b))
+
 #define  CHECKRAD	1.5	/* radius to check for filtering */
 
 COLOR  exposure = WHTCOLOR;	/* exposure for the frame */
@@ -51,6 +53,8 @@ int  xres, yres;		/* resolution of input */
 double  inpaspect = 1.0;	/* pixel aspect ratio of input */
 int  correctaspect = 0;		/* aspect ratio correction? */
 
+int  wrongformat = 0;
+
 int  xrad;			/* x window size */
 int  yrad;			/* y window size */
 
@@ -121,6 +125,12 @@ char  **argv;
 					d = pow(2.0, atof(argv[i+1]));
 				else
 					d = atof(argv[i+1]);
+				if (d < 1e-20 || d > 1e20) {
+					fprintf(stderr,
+						"%s: exposure out of range\n",
+							argv[0]);
+					exit(1);
+				}
 				switch (argv[i][2]) {
 				case '\0':
 					scalecolor(exposure, d);
@@ -178,7 +188,20 @@ char  **argv;
 			}
 		else
 			break;
-			
+					/* get lamp data (if necessary) */
+	if (lamptype != NULL) {
+		if (loadlamps(lampdat) < 0)
+			quit(1);
+		if ((lampcolor = matchlamp(lamptype)) == NULL) {
+			fprintf(stderr, "%s: unknown lamp type\n", lamptype);
+			quit(1);
+		}
+		colval(exposure,RED) /= lampcolor[0];
+		colval(exposure,GRN) /= lampcolor[1];
+		colval(exposure,BLU) /= lampcolor[2];
+		freelamps();
+	}
+					/* open input file */
 	if (i == argc) {
 		if (singlepass)
 			fin = stdin;
@@ -205,21 +228,13 @@ char  **argv;
 		fprintf(stderr, "%s: bad # file arguments\n", progname);
 		quit(1);
 	}
-					/* get lamp data (if necessary) */
-	if (lamptype != NULL) {
-		if (loadlamps(lampdat) < 0)
-			quit(1);
-		if ((lampcolor = matchlamp(lamptype)) == NULL) {
-			fprintf(stderr, "%s: unknown lamp type\n", lamptype);
-			quit(1);
-		}
-		colval(exposure,RED) /= lampcolor[0];
-		colval(exposure,GRN) /= lampcolor[1];
-		colval(exposure,BLU) /= lampcolor[2];
-		freelamps();
-	}
 					/* get header */
-	getheader(fin, headline);
+	getheader(fin, headline, NULL);
+	if (wrongformat) {
+		fprintf(stderr, "%s: input must be a Radiance picture\n",
+				progname);
+		quit(1);
+	}
 					/* add new header info. */
 	printargs(i, argv, stdout);
 					/* get picture size */
@@ -265,9 +280,15 @@ char  **argv;
 headline(s)				/* process line from header */
 char  *s;
 {
+	char  fmt[32];
+
 	fputs(s, stdout);		/* copy to output */
 	if (isaspect(s))		/* get aspect ratio */
 		inpaspect *= aspectval(s);
+	else if (isformat(s)) {
+		formatval(fmt, s);
+		wrongformat = strcmp(fmt, COLRFMT);
+	}
 }
 
 
@@ -366,6 +387,7 @@ FILE  *in;
 
 scan2init()			/* prepare scanline arrays */
 {
+	COLOR	ctmp;
 	double  d;
 	register int  i;
 
@@ -381,7 +403,7 @@ scan2init()			/* prepare scanline arrays */
 
 		initmask();		/* initialize filter table */
 	}
-	barsize = 2 * yrad;
+	barsize = 2*yrad + 1;
 	scanin = (COLOR **)malloc(barsize*sizeof(COLOR *));
 	for (i = 0; i < barsize; i++) {
 		scanin[i] = (COLOR *)malloc(xres*sizeof(COLOR));
@@ -395,17 +417,25 @@ scan2init()			/* prepare scanline arrays */
 		fprintf(stderr, "%s: out of memory\n", progname);
 		quit(1);
 	}
-					/* record pixel aspect and exposure */
+					/* record pixel aspect ratio */
 	if (!correctaspect) {
 		d = x_c / y_r;
-		if (d < .99 || d > 1.01)
+		if (!FEQ(d,1.0))
 			fputaspect(d, stdout);
 	}
+					/* record exposure */
 	d = bright(exposure);
-	if (d < .995 || d > 1.005)
+	if (!FEQ(d,1.0))
 		fputexpos(d, stdout);
+					/* record color correction */
+	copycolor(ctmp, exposure);
+	scalecolor(ctmp, 1.0/d);
+	if (!FEQ(colval(ctmp,RED),colval(ctmp,GRN)) ||
+			!FEQ(colval(ctmp,GRN),colval(ctmp,BLU)))
+		fputcolcor(ctmp, stdout);
 	printf("\n");
-	fputresolu(YMAJOR|YDECR, ncols, nrows, stdout);	/* resolution */
+					/* write out resolution */
+	fputresolu(YMAJOR|YDECR, ncols, nrows, stdout);
 }