CE AD - Contrast Enhancement - Anisotropic Diffusion

(7/15/03)

PURPOSE

Contrast 'enhancement' or denoising using anisotropic diffusion on image/volume.   Example.

SEE ALSO

CE MED [Contrast Enhancement - Median Filtering]

USAGE

.OPERATION: CE AD

.INPUT FILE: VOL001
[Enter name of the input file.]

.OUTPUT FILE: VOL002
[Enter name for output file.]

.CPF, MCD, OR HEG?: CPF
[Currently there are three different implementations:
CPF is Estes 'Corner preserving formulation.
MCD is Estes 'Mean curvature diffusion formulation.
HEG is Frangakis & Hegerl's formulation.

.ITERATIONS: 9
[Number of iterations.]

If 'MCD' is chosen the following question appears.

.WEIGHTING FACTOR: 1.0
[Weighting factor.]

If 'HEG' is chosen the following two questions appear.

.TIME STEP(0...0.25): .1

.SIGMA & LAMBDA: 1.0 1.0
[Sigma is standard deviation for Gaussian smoothing. Lambda is a contrast parameter.]

NOTES

  1. In option 'CPF' image/volume has 2 pixel boundary set to zero. The input data is automatically normalized over 0...1.0 before application of the algorithm. Finally the original image range is recreated. This option works in 2D, slice-by-slice on a volume.

  2. In option 'MCD' image/volume has a 1 pixel boundary set to zero. The input data is automatically normalized over 0...1.0 before application of the algorithm. Finally the original image range is recreated. This option works in 2D, slice-by-slice on a volume.

  3. Options 'CPF' & 'MCD' implement Adel's algorithm. Ported from 'C' code written by Robert R. Estes Jr.
    Copyright (C)1997 by Robert R. Estes Jr.
    References: Adel I. El-Fallah, Gary E. Ford: "The Evolution of Mean Curvature in Image Filtering", in "Proceedings of the IEEE International Conference on Image Processing ", pp 298-302, 1994.
    Also see: http://msp.cipic.ucdavis.edu/~ford/papers/ip97.ps, and http://www.ece.ucdavis.edu/~ford/research/papers/prl.ps.

    Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation. This software is provided "as is" without express or implied warranty.

  4. Option 'HEG' implements Frangakis & Hegerl's formulation.
    Ported from 'C' code written by Frangakis.
    Copyright (C) 2001 by Frangakis
    This option works in 3D on a volume.

SUBROUTINES

ANISO, ANISOE, ANISOF, ANISOF3

CALLER

UTIL2

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