Algorithm Reference

Here is an overview of the available phase unwrapping algorithms in this package. Scikit-image’s unwrap algorithm is not rewritten here, it is just included for convenience and comparison. It still only works on the CPU.

The links at the bottom of the page will bring you to a mathematical description of each algorithm.

For an introduction to the Phase Unwrapping problem, see the excellent 1D and 2D introductions written by Dr. Munther Gdeisat and Dr. Francis Lilley. You can find them online with the titles:

• “One-Dimensional Phase Unwrapping Problem By Dr. Munther Gdeisat and Dr. Francis Lilley”

• “Two-Dimensional Phase Unwrapping Problem By Dr. Munther Gdeisat and Dr. Francis Lilley”

Overview

Algorithm overview

Algorithm	Speed	GPU friendly	Handles discontinuity	References
LS Poisson (xpunwrap.algo_ls_poisson)	very fast	excellent	poor	Ghiglia & Pritt (1998)
LS Poisson (Periodic Grad) (xpunwrap.algo_ls_poisson_pg)	very fast	excellent	poor	Ghiglia & Pritt (1998)
Weighted LS (xpunwrap.algo_ls_weighted)	medium	good	moderate	D. C. Ghiglia & L. A. Romero (1994), Ghiglia & Pritt (1998)
Reliability Path (for comparison) (xpunwrap.algo_skimage_unwrap)	medium	CPU-only	excellent	skimage example

• Least-Squares Poisson (algo_ls_poisson)
• Least-Squares with Periodic Gradients (algo_ls_poisson_pg)
• Weighted Least-Squares (algo_ls_weighted)