Events
The Taub Faculty of Computer Science Events and Talks
Iddit Shalem (M.Sc. Thesis Seminar)
Wednesday, 21.06.2006, 11:30
In this work we study the problem of two-dimensional phase
unwrapping and propose two algorithms for its solution.
Two-dimensional phase unwrapping is the problem of deducing
unambiguous ``phase" from values known only modulo $2\pi$. Many
authors agree that the objective of phase unwrapping should be to
find a weighted minimum of the number of places where adjacent
(discrete) phase values differ by more than $\pi$ (called
discontinuities). This NP-hard problem is of considerable
practical interest, largely due to its importance in interpreting
data acquired with synthetic aperture radar (SAR) interferometry.
Consequently, many heuristic algorithms have been proposed. Our
first algorithm considers the wrapped phase array as a grey level
image and applies the image segmentation problem to this image.
Based on the segmentation, we develop an efficient relaxation
method for decreasing discontinuities in the phase image. The
second algorithm presents an efficient multi-level graph algorithm
for the approximate solution of an equivalent problem---minimal
residue cut in the dual graph.