--- ray/src/px/mt160r.c	1990/01/26 08:17:31	1.6
+++ ray/src/px/mt160r.c	1991/04/18 14:35:09	1.7
@@ -49,7 +49,10 @@ char  *fname;
 		return(-1);
 	}
 				/* discard header */
-	getheader(input, NULL);
+	if (checkheader(input, COLRFMT, NULL) < 0) {
+		fprintf(stderr, "%s: not a Radiance picture\n", fname);
+		return(-1);
+	}
 				/* get picture dimensions */
 	if (fgetresolu(&xres, &yres, input) != (YMAJOR|YDECR)) {
 		fprintf(stderr, "%s: bad picture size\n", fname);