RETRO commands


PROGRAM NAME

venhance - Enhance Image Using the Local Standard Deviation & Mean (K1)

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 performing 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

OPTIONAL ARGUMENTS

-w
type: integer
desc: window width of local area
default: 3
bounds: 1 < [-w] < 100
-h
type: integer
desc: window height of local area
default: 3
bounds: 1 < [-h] < 100
-k
type: float
desc: specifies scale factor
default: 0.5
bounds: 0 < [-k] < 1
-v
type: float
desc: specifies minimum standard deviation
default: 1
bounds: 0 < [-v] < 2000

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

Reference: Digital Image Processing (2nd Edition) by Gonzalez and Wintz.

RESTRICTIONS

venhance only operates on byte type images.

REFERENCES

Digital Image Processing (2nd Edition) by Gonzalez and Wintz.

COPYRIGHT

Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.