Index: trunk/Ohana/src/opihi/cmd.data/imhist.c
===================================================================
--- trunk/Ohana/src/opihi/cmd.data/imhist.c	(revision 15274)
+++ trunk/Ohana/src/opihi/cmd.data/imhist.c	(revision 15442)
@@ -41,5 +41,5 @@
 
   if (argc != 4) {
-    gprint (GP_ERR, "USAGE: histogram <buffer> <x> <y> [-region sx sy nx ny] [-range min max]\n");
+    gprint (GP_ERR, "USAGE: histogram <buffer> <x> <y> [-region sx sy nx ny] [-range min max] [-delta binsize]\n");
     return (FALSE);
   }