vlpf(1)

PROGRAM
vlpf - Perform a low-pass filtering operation on an image in the frequency domain.

SYNTAX

vlpf

-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 Butterworth Filter [True]

[-V]
    Gives the version for vlpf

[-U]
    Gives the usage for vlpf

[-P]
    Prompts for command line options

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

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

DESCRIPTION
vlpf performs a low-pass filtering operation on an image in the frequency domain. The filter cutoff is a radius normalized 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 Butterworth Filter [True]
    default: false

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

This command low 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), lvlpf(3)

RESTRICTIONS
vlpf will complain if asked to operate on non COMPLEX data storage type images.

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

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