
vhpf(1)                      Khoros                       vhpf(1)

PROGRAM
     vhpf - Perform a high-pass filtering operation on an image
     in the frequency domain.

SYNTAX
     vhpf

     -i             first input image

     -o             resulting output image

     -n             selects the order of the filter

     -c             selects the cut off radius

     [-t]           Choose Exponential Filter [False] or Butter-
                    worth Filter [True]

     [-V]           Gives the version for vhpf

     [-U]           Gives the usage for vhpf

     [-P]           Prompts for command line options

     [-A [file1]]   Creates the answer file called vhpf.ans or
                    file1

     [-a [file1]]   Uses vhpf.ans or file1 as the answer file

DESCRIPTION
     vhpf performs a high-pass filtering operation on an image in
     the frequency domain. The filter cutoff is a radius normal-
     ized to the longest image dimension (lets you filter non-
     square images, but with an elliptical cutoff area). The
     order of the filter is an integer specifying the sharpness
     of the cutoff.

REQUIRED ARGUMENTS
     -i     type: infile
            desc: first input image

     -o     type: outfile
            desc: resulting output image

     -n     type: integer
            desc: selects the order of the filter

     -c     type: float
            desc: selects the cut off radius

OPTIONAL ARGUMENTS
     -t     type: boolean
            desc: Choose Exponential Filter [False] or Butter-
            worth Filter [True]
            default: false

EXAMPLES
     vhpf -i input.image -o output.image -n 1 -c 1 -t 0

     This command high-pass filters input.image and stores the
     result in output.image.  The order of the filter is 1 and
     the cutoff radius is 1.  An exponential filter is used.

SEE ALSO
     intro(1), verror(3), vgparms(3), vutils(3), lvhpf(3)

RESTRICTIONS
     vhpf will complain if asked to operate on non COMPLEX input
     images.

     Filters of high order can take a long time to do their work.

COPYRIGHT
     Copyright 1991, University of New Mexico.  All rights
     reserved.

Khoros                    Release: 1.0                          1

