A fast phase unwrapping algorithm based on minimum discontinuity by blocking

Abstract

Two-dimensional phase unwrapping is one of the key problems in many signal processing applications. Flynn's minimum discontinuity phase unwrapping is one of the algorithm which can solve many different kinds of phase unwrapping problems successfully, but its computation efficiency is too low. To overcome this drawback, a blocked minimum discontinuity phase unwrapping algorithm is proposed. In the proposed algorithm, the wrapped phase image is tessellated into small blocks. Each block is unwrapped separately by minimum discontinuity phase unwrapping algorithm, and then the unwrapped blocks are merged together using minimum discontinuity approach again. The merging process has been divided into two steps. The discontinuities between the blocks are minimized firstly, and then the unwrapped image is taken as a whole to minimize the total discontinuities. This proposed algorithm is described in detail and tested on an IFSAR experimental wrapped phase image and the Etna wrapped image. Results show that the proposed algorithm works well and is more efficient than the Flynn's minimum discontinuity algorithm.