
vmarr(1)                     Khoros                      vmarr(1)

PROGRAM
     vmarr - Create a Marr type edge detection filter kernel.

SYNTAX
     vmarr

     -o             Marr kernel output image

     [-trigger]     trigger input

     [-r]           specify the number of rows in the kernel

     [-c]           specify the number of columns in the kernel

     [-v]           variance of the Gaussian

     [-V]           Gives the version for vmarr

     [-U]           Gives the usage for vmarr

     [-P]           Prompts for command line options

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

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

DESCRIPTION
     creates a convolution filter kernel using the following
     equation.  pixel = [-1/(PI*var*var)]*[1-r*r/(2*var)]*exp[-
     r*r/(2*var)], where r is the calculated distance from the
     center of the kernel.

     A Marr filter is the Laplacian of a Gaussian, and is
     intended for high lighting image edges and at the same time
     smooth out the noise.  vmarr creates image data of type
     float.

     The trigger input can be used to cause vcustom to re-execute
     when used inside cantata. No image is read from this input.

REQUIRED ARGUMENTS
     -o     type: outfile
            desc: Marr kernel output image

OPTIONAL ARGUMENTS
     -trigger
            type: infile
            desc: trigger input

     -r     type: integer
            desc: specify the number of rows in the kernel
            default: 3
            bounds: value > 0

     -c     type: integer
            desc: specify the number of columns in the kernel
            default: 3
            bounds: value > 0

     -v     type: float
            desc: variance of the Gaussian
            default: 1
            bounds: value > 0.0

EXAMPLES
SEE ALSO
     intro(1), verror(3), vgparms(3), vutils(3), lvmarr(3) vcus-
     tom(1)

RESTRICTIONS
     only generates float kernels, vconvert can change the image
     to other data types.

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

Khoros                    Release: 1.0                          1

