PNMDEPTH

NAME

      pnmdepth - change the maxval in a portable anymap

SYNOPSIS

      pnmdepth newmaxval [pnmfile]

DESCRIPTION

      Reads a portable anymap as input.  Scales all the pixel values, and
      writes out the image with the new maxval.  Scaling the colors down to
      a smaller maxval will result in some loss of information.
      Be careful of off-by-one errors when choosing the new maxval.  For
      instance, if you want each color values to be five bits wide, use a
      maxval of 31, not 32.

DEMONSTRATION

      Let a.pnm be a portable anymap.
      The following command will change its maxval to 31:
	pnmmerge pnmdepth 31 a.pnm >a31.pnm

BEFORE

maxval=255

AFTER

pnmdepth 63

pnmdepth 15

pnmdepth 3

SEE ALSO

      pnm(5), ppmquant(1), ppmdither(1)

AUTHOR

      Copyright (C) 1989, 1991 by Jef Poskanzer.