提出了一种用于数字全息显微术的可靠度导向快速相位展开算法。对可靠度参数进行非线性量化,结合查表法实现数字全息再现像的相位可靠快速展开。在截断相位图中找出残差点,以残差点的物光强度最大值为阈值,将测量区域分为可信区域和非可信区域。将可信区域的可靠度设为最大,非可信区域的光强进行量化,作为其可靠度。这样制作了一张非线性质量图。利用该质量图,结合查表洪水算法进行相位展开。实验中,采用非线性查找表的相位展开算法比传统洪水算法快68倍以上,比枝切法快近3倍。结果表明,该算法在保持高质量相位展开的情况下大大提高了速度。
A fast reliability-guided phase unwrapping algorithm for digital holography is proposed. The value of reliability is nonlinearly quantized to form a quality map. The phase is unwrapped reliably and fast by combining the nonlinear quality map with look-up table operation. The residues are searched in the wrapped phase map, and the maximum intensity of residues is set as threshold. The measured region is segmented to the reliable region and the doubtful region by the threshold. A nonlinear quality map is derived by setting the reliability of reliable region to maximum and setting those of the doubtful region to quantized value of intensity. Flood-fill algorithm using look-up table is implemented with the nonlinear quality map to unwrap the phase map. In experiments, the speed of proposed algorithm is about 68 times faster than that of conventional flood-fill algorithm and about 3 times faster than that of branch cut algorithm. The experimental results demonstrate that the speed of proposed algorithm is significantly increased and the quality of unwrapped phase is good as well.