Title 



Realtime phase unwrapping in Fourier space using a graphics processing unit
 
Author 



 
Abstract 



Numerous imaging techniques deliver measurement data which are mathematically constricted or wrapped to the finite interval [pi, pi], corresponding to the principle value domain of the arctangent function. A wide range of reconstruction algorithms has been developed to obtain the true, unwrapped phase by adding an integral multiple of 2 pi to each point of the wrapped grid. However, the phase unwrapping procedure is hampered by the presence of noise, phase vortices or insufficiently sampled digital data. Therefore, reliable phase unwrapping algorithms are generally computationally intensive and their design often requires multiple iterations to reach convergence, leading to high execution times. This is a limiting factor for many realtime applications that require phase data to be unwrapped before visualization. In this paper, we present the parallel implementation of a singlestep Fourierbased phase unwrapping algorithm that is robust against noise and phase residues. By executing the proposed algorithm on the graphics processing unit of a standard graphics card, we were able to reduce the total processing time of the phase unwrapping algorithm to < 5ms when executed on a 640x480pixel input map containing an arbitrarily high density of phase jumps. In addition, we expand upon this technique by inserting the obtained solution as a preconditioner in a conjugate gradient technique. This way, the user is able to provide the algorithm with an input map of pixel quality, helping the phase unwrapping algorithm to reach convergence iteratively.   
Language 



English
 
Source (journal) 



OPTICAL MEASUREMENT TECHNIQUES FOR STRUCTURES & SYSTEMS III  
Source (book) 



6th International Conference on Optical Measurement Techniques for, Structures and Systems III (OPTIMESS2015), APR 0809, 2015, Univ Antwerp, Univ Antwerp, Antwerp, BELGIUM  
Publication 



Maastricht : Shaker publishing bv, 2016
 
ISBN 



9789042304390
 
Volume/pages 



(2016), p. 321330
 
ISI 



000373413300033
 
