Robust unwrapping algorithm for 3-D phase volumes of arbitrary shape containing knotted phase singularity loops
2005 (English)Report (Other academic)
The extension of path-independent 2-D phase unwrapping algorithms, based on placement of branch cut lines between phase singularities of opposite sign, was recently proposed for phase volumes in a recent paper by Huntley. In 3-D the singularities were shown to form closed loops and path-independence was achieved by placing branch cut surfaces across the loops. In the current paper we describe in detail an optimised and extended version of Huntley's algorithm. This deals in particular with two aspects which are essential for practical phase volumes: (1) how to close partial loops which pass through arbitrary boundaries separating valid and invalid phase data, and (2) how to select the set of loops having shortest length. The second algorithm is necessary to deal with the ambiguous cases that can arise when the singularities form knots, i.e. two loops pass through a single phase volume element. The perfomance of the algorithm is demonstrated on 3-D phase maps from two types of medical imaging data: MRI and x-ray interferometry.
Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2005. , 25 p.
Research report / Luleå University of Technology, ISSN 1402-1528 ; 2005:16
Research subject Industrial Electronics
IdentifiersURN: urn:nbn:se:ltu:diva-24918Local ID: d0c54e40-b2c3-11db-bf9d-000ea68e967bOAI: oai:DiVA.org:ltu-24918DiVA: diva2:997970
Godkänd; 2005; 20070202 (ysko)2016-09-292016-09-29Bibliographically approved