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2D phase unwrapping algorithms

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2D phase unwrapping algorithms

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22 Dec 2008 (Updated )

Implementations of the phase quality path following method and Goldstein's branch cut method.

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Description

Two 2D phase unwrapping approaches are included:
1. Phase quality guided path following method.
2. Goldstein's branch cut method.

The algorithms are described in:
D. C. Ghiglia and M. D. Pritt, Two-Dimensional Phase Unwrapping:
Theory, Algorithms and Software. New York: Wiley-Interscience, 1998.

Acknowledgements

This file inspired Goldstein Unwrap2 D R1, Quality Guided Unwrap2 D R1, and Nf2 Ff.

MATLAB release MATLAB 7.5 (R2007b)
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Comments and Ratings (8)
26 May 2014 Bahar

Helped me a lot!

15 Sep 2012 Tim Zaman

Remarkably slow..

15 Sep 2012 Tim Zaman  
09 Aug 2012 peter  
17 Jul 2012 Armin Ka

Hi,
I need a phase unwrapping algorithm to unwrap the interference phase which is bounded between -pi, pi or 0, 2*pi
Thanks for your help.
A

05 Mar 2010 Eric

Useful for unwrapping small images, but not for large images. A 510x510 array took 25 minutes on my machine. The following improvements need to be made for larger arrays:

1. Implement the "postponed" list described in Ghiglia and Pritt.
2. Avoid using Matlab's unwrap() function for unwrapping a length-two vector. Instead use Itoh's Method for a length 2 vector explicitly:
D = psi(2)-psi(1);
delta = atan2(sin(D),cos(D);
phi = psi(1) + delta;
3. Resize matrices as vectors

This yields about 20X speed improvement for the 510x510 array size.

15 May 2009 Hex  
26 Feb 2009 Deva

Thanks for the contribution!! It is a much more elegant code than the one I was attempting to write from the pseudocode!

As I was testing out the code, I noticed that the algorithm does not go back and unwrap the branch cut pixels, as is described in Ghiglia and Pritt. Perhaps that would be a good addition to the next version?

Updates
23 Feb 2009

Modified the Goldstein algorithm to allow only part of a phase image to be unwrapped.

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