像面数字全息显微中的相位解包裹算法研究

为了快速准确地恢复出由像面数字全息显微术(IPDHM)得到的被测样品准确的相位分布,采用理论分析和实验验证相结合的方法,对5种相位解包裹算法的速度、准确性及适用范围等相关问题进行了研究。结果表明:对由IPDHM得到的含有欠采样区域的包裹相位图进行相位展开时,基于横向剪切的最小二乘法效果最好、速度最快;利用枝切法和质量导向图法处理的结果存在"拉线"和未展开区域,造成严重的解包裹错误;利用基于离散余弦变换(DCT)的最小二乘法和预条件共轭梯度法会使欠采样区域的误差进行传递,使得解包裹相位产生较大误差。因此,基于横向剪切干涉的最小二乘法是目前IPDHM中的最优相位解包裹算法。

Phase unwrapping algorithms in image plane digital holographic microscopy

In order to recover the accurate phase distribution of the tested sample rapidly by the image plane digital holographic microscopy(IPDHM),the basic problems,such as accuracy,speed,applying scope and others of five kinds of phase unwrapping algorithms are studied by theoretical analysis and experimental verification.The results show that the lateral shearing interferometry method based on least square is the best and fastest way to recover the phase which has under-sampling problem.Branch cut method on quality-guided path following method may cause serious errors because of streaks phenomenon and some not unwrapped areas.The discrete cosine transform(DCT) method based on least squares and preconditioned conjugate gradient(PCG) method may result in great error because the error can be transferred in the under-sampling area.Therefore,the lateral shearing interferometry method based on least square is the optimal phase unwrapping algorithm in IPDHM.