Real-time pipelined heterogeneous system for windowed Fourier filtering and quality guided phase unwrapping algorithm using Graphic Processing Unit

Abstract

Phase unwrapping refers to the reconstruction process of a continuous phase distribution from a wrapped phase map in optical interferometers, fringe projection systems and synthetic aperture radars. Usually, phase unwrapping (PU) is challenging due to speckle noise, atmosphere interference, and long discontinuities. Two dimensional phase unwrapping algorithms have been developed for several decades including the classic path‐following PU algorithm and path independent minimum‐norm PU algorithms. Being one of the path‐following algorithms, quality‐guided phase unwrapping algorithm relies on a quality map to guide the integration path. Recently, quality‐guided phase unwrapping algorithm along with WFF processing (WFF‐QG) was developed. It can provide better quality map compared with commonly used phase derivative variance (PDV) and largely improve the reliability of quality guided phase unwrapping algorithm. However, the WFF‐QG algorithms are computationally expensive, prohibiting it from real‐time applications. In this paper, to realize real‐time WFF‐QG algorithm, we propose a pipelined heterogeneous system based on CPU and graphic processing unit. Using NVIDIA GTX285 graphics card and quad‐core 2.5 GHz Intel(R) Xeon(R) CPU E5420, 2.15 frames per second (fps) can be achieved by WFF‐QG algorithm for real‐time continuous phase retrieval with size 256×256. Moreover, up to 62.3× speedup compared with the sequential codes in the same CPU has been achieved.