USAGE: fltrfreq inimg outimg [-l f1] [-h f1] [-b f1 f2]
                            [-s f1 f2] [-n ORDER] [-g] [-p] [-I] [-L]

fltrfreq performs frequency domain filtering on image.

ARGUMENTS:
    inimg: input image filename (TIF)
   outimg: output image filename (TIF)

OPTIONS:
     -l f1: LOW-PASS FILTER passing frequencies below cutoff, f1.
     -h f1: HIGH-PASS FILTER passing frequencies above cutoff, f1.
  -b f1 f2: BAND-PASS FILTER passing frequencies between f1-f2.
  -s f1 f2: STOP-BAND-PASS FILTER passing frequencies not f1-f2.
  -n ORDER: order of Butterworth filter, dflt = 1.
        -g: flag to perform Gaussian filter, default is Butterworth.
        -p: flag for zero padding if set, and image row or column is
            not a power of 2, image size is increased by zero-.
            padding; otherwise image size is decreased (default).

            NOTE -- The frequencies (f1,f2) should be expressed as a
            number 0 to 1.0; this is a fractional frequency value of the
            full original pass band. For example, a low-pass filter with
            cutoff frequency of 0.5 will reduce the bandwidth by half.
            Where the image is not square, the fractional frequency
            value is relative to the higher frequency corresponding to
            the longer x or y axis.
        -I: invert image before processing
        -L: print Software License for this module
 

Example:

fltrfreq fltr0.tif fltrLP.tif -l 0.25 -I
 

fltr0.tif:

fltrLP.tif:

Copyright (C) 1999 MLMSoftware Group, LLC.