Two-dimensional Phase Unwrapping Method Using Cost Function of L0 Norm

Abstract

Considering cost model and convergence speed of the minimum norm unwrapping, a highly efficient two-dimensional global phase unwrapping method optimized with L0 norm is proposed. As analysing features of cost model in phase unwrapping with minimum norm, a cost function definition is provided in line with the L0 norm, which impose a stronger constraint in the tangent direction of phase discontinuity boundary than that in normal direction, in order to preserve integrity of discontinuity during iterative unwrapping processing for continuous phase. For the sake of slow speed of low-frequency error convergence during linear solving, a data partitioning strategy is introduced into unwrapping processing. Due to independence of minimum norm method in blocks, linear solving only focus on high-frequency information and improve efficiency of iterative work, and the low-frequency processing part is transferred to offsetting-aligning between blocks. With experiments and analysis, reliability and efficiency of the novel phase unwrapping method are certified comparing to existing methods.