--- ray/src/px/ra_t8.c	1990/03/12 15:14:46	1.7
+++ ray/src/px/ra_t8.c	1991/08/23 13:40:01	1.11
@@ -1,4 +1,4 @@
-/* Copyright (c) 1986 Regents of the University of California */
+/* Copyright (c) 1991 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -51,8 +51,10 @@ extern long  ftell();
 
 extern double  atof(), pow();
 
-double	gamma = 2.0;			/* gamma correction */
+double	gamma = 2.2;			/* gamma correction */
 
+int  bradj = 0;				/* brightness adjustment */
+
 pic	*inpic;
 
 char  *progname;
@@ -95,6 +97,11 @@ char  *argv[];
 			case 'b':
 				greyscale = 1;
 				break;
+			case 'e':
+				if (argv[i+1][0] != '+' && argv[i+1][0] != '-')
+					goto userr;
+				bradj = atoi(argv[++i]);
+				break;
 			case 'c':
 				ncolors = atoi(argv[++i]);
 				break;
@@ -125,12 +132,13 @@ char  *argv[];
 		}
 					/* put header */
 		printargs(i, argv, stdout);
+		fputformat(COLRFMT, stdout);
 		putchar('\n');
 		fputresolu(YMAJOR|YDECR, xmax, ymax, stdout);
 					/* convert file */
 		tg2ra(&head);
 	} else {
-		if (i > argc-1 || i < argc-2)
+		if (i < argc-2 || (!greyscale && i > argc-1))
 			goto userr;
 		if ((inpic = openinput(argv[i], &head)) == NULL) {
 			sprintf(errmsg, "can't open input \"%s\"", argv[i]);
@@ -153,9 +161,9 @@ char  *argv[];
 	quiterr(NULL);
 userr:
 	fprintf(stderr,
-	"Usage: %s [-d][-c ncolors][-b][-g gamma] input [output]\n",
+	"Usage: %s [-d][-c ncolors][-b][-g gamma][-e +/-stops] input [output]\n",
 			progname);
-	fprintf(stderr, "   Or: %s -r [-g gamma] [input [output]]\n",
+	fprintf(stderr, "   Or: %s -r [-g gamma][-e +/-stops] [input [output]]\n",
 			progname);
 	exit(1);
 }
@@ -282,10 +290,10 @@ register struct hdStruct  *h;
 		p->fp = stdin;
 	else if ((p->fp = fopen(fname, "r")) == NULL)
 		return(NULL);
-					/* discard header */
-	getheader(p->fp, NULL);
-	if (fgetresolu(&xmax, &ymax, p->fp) != (YMAJOR|YDECR))
-		quiterr("bad picture size");
+					/* get header info. */
+	if (checkheader(p->fp, COLRFMT, NULL) < 0 ||
+			fgetresolu(&xmax, &ymax, p->fp) != (YMAJOR|YDECR))
+		quiterr("bad picture format");
 	p->nexty = 0;
 	p->bytes_line = 0;		/* variable length lines */
 	p->pos.y = (long *)ecalloc(ymax, sizeof(long));
@@ -339,7 +347,8 @@ struct hdStruct  *hp;
 					pow((map.c4[i][3]+.5)/256.,gamma),
 					pow((map.c4[i][2]+.5)/256.,gamma),
 					pow((map.c4[i][1]+.5)/256.,gamma));
-
+	if (bradj)
+		shiftcolrs(ctab, 256, bradj);
 					/* allocate targa data */
 	tarData = taralloc(hp);
 					/* get data */
@@ -382,7 +391,7 @@ register rgbpixel  *l3;
 		quiterr("read error in picreadline3");
 	inpic->nexty = y+1;
 							/* convert scanline */
-	normcolrs(inl, xmax, 0);
+	normcolrs(inl, xmax, bradj);
 	for (i = 0; i < xmax; i++) {
 		l3[i].r = inl[i][RED];
 		l3[i].g = inl[i][GRN];
@@ -465,7 +474,7 @@ colormap  map;
 	register int  i, val;
 
 	for (i = 0; i < 256; i++) {
-		val = pow(i/256.0, 1.0/gamma) * 256.0;
+		val = pow((i+0.5)/256.0, 1.0/gamma) * 256.0;
 		map[0][i] = map[1][i] = map[2][i] = val;
 	}
 }