
venhance(1)                  Khoros                   venhance(1)

PROGRAM
     venhance - Enhances an image using the local standard devia-
     tion and mean.

SYNTAX
     venhance

     -i             input image filename

     -o             output image filename

     -w             window width of local area

     -h             window height of local area

     -k             specifies scale factor

     -v             specifies minimum standard deviation

     [-V]           Gives the version for venhance

     [-U]           Gives the usage for venhance

     [-P]           Prompts for command line options

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

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

DESCRIPTION
     venhance uses a local transformation based on the mean and
     variance of the intensity maps and the intensity of the
     input image f(x,y) to create a new image g(x,y) by perform-
     ing the following transformation at each pixel location
     (x,y):

             g(x,y) = A(x,y).[f(x,y) -m(x,y)] + m(x,y),

     where

             A(x,y) = k . M / sigma(x,y)     0 < k < 1

     where m(x,y) and sigma(x,y) are the gray-level mean and
     standard deviation computed in a neighborhood centered at
     (x,y), M is the global mean of f(x,y), and k is a constant
     in the range indicated above.

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

     -o     type: outfile
            desc: output image filename

     -w     type: integer
            desc: window width of local area

     -h     type: integer
            desc: window height of local area

     -k     type: float
            desc: specifies scale factor

     -v     type: float
            desc: specifies minimum standard deviation

OPTIONAL ARGUMENTS
     none

EXAMPLES
     venhance -i input.image -o output.image -w 5 -h 5 -k .5 -v 2

     This command performs image enhancement on input.image and
     stores the result in output.image.  The size of the window
     used is 5 by 5.  The tuning factor is .5 and the minimum
     allowable standard deviation is 2.

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

     Reference: Digital Image Processing (2nd Edition) by Gon-
     zalez and Wintz.

RESTRICTIONS
     venhance only operates on byte type images.

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

Khoros                    Release: 1.0                          1

