FBNORM(1)                USER COMMANDS                  FBNORM(1)



NAME
     fbnorm - normalize and adjust grayscale or color image

SYNOPSIS
     fbnorm [ -b<val> -w<val> ] [ -<type> ] < image > image

DESCRIPTION
     Extends the contrast range to a full 0 to  255.   The  argu-
     ments  -b  and -w given the percentage of the darkest pixels
     to map to black and lightest pixels to map to white.

     For color images the default is to discard 0.5% each of  the
     darkest and lightest pixels.  Increasing the contrast beyond
     that may result in significant color artifacts (because  the
     color values will be partially clipped).

OPTIONS
     -b<num>,-w<num>
          _p_e_r_c_e_n_t_a_g_e _b_l_a_c_k, _w_h_i_t_e pixels to map to 0,  255.   The
          default  for grayscale images is to "discard" 2 percent
          of the black pixels and 1 percent of the white  pixels.
          For color images both values default to 0.5 percent.

          An alternate form is to  specify  two  integers,  which
          will then be linearly mapped to 0 and 255.

EXAMPLE
     To normalize a grayscale FBM image using defaults:

         % fbnorm < foo.fbm > bar.fbm

     To increase contrast by discarding 10 percent of  the  black
     pixels and 5 percent of the white pixels:

         % fbnorm -b10 -w5 < foo.fbm > bar.fbm

     Or, if you know that you want 34 to map to 0 and 197 to  map
     to 255, you can just type:

         % fbnorm 34 197 < foo.fbm > bar.fbm

SEE ALSO
     fbm(1) for general discussion, pbm(1) for PBM routines.

BUGS
     None known.

HISTORY
     Copyright (c) 1989 by  Michael  L.  Mauldin.  Permission  is
     granted  to  use  this  program in whole or in part provided
     that you do not sell it for profit and that  this  copyright
     notice is retained unchanged.



Sun Release 4.0      Last change: 07-Mar-89                     1






FBNORM(1)                USER COMMANDS                  FBNORM(1)



     07-Mar-89  Michael L. Mauldin at Carnegie Mellon University
          Beta release (version 0.9) mlm@cs.cmu.edu





















































Sun Release 4.0      Last change: 07-Mar-89                     2