Authors:

Marklund, O., Huntley, J.M., & CUSACK, R

Reference:

Year of publication:

2007

CBU number:

6601

Abstract:

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 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 work, we describe^ in detail an optimized and extended version of Huntley's algorithm.^ It deals in particular with two aspects that are essential^ for practical phase volumes: 1. how to close partial loops^ that pass through arbitrary boundaries separating valid and invalid phase^ data, and 2. how to select the set of loops^ having the shortest length. The second algorithm is necessary to^ deal with ambiguous cases that can arise when the singularities^ form knots, i.e., two loops pass through a single phase^ volume element. The performance of the algorithm is demonstrated on^ 3-D phase maps from two types of medical imaging data:^ medical resonance imaging (MRI) and x-ray interferometry.