为了快速准确地对含有噪声的包裹相位图进行相位展开, 采用理论分析与计算机模拟及实验验证相结合的方法, 对基于快速傅里叶变换(FFT)的四种典型算法--四次FFT算法(4-FFT)、二次FFT算法(2-FFT)、四次离散余弦变换算法(4-DCT)及横向剪切干涉与FFT相结合的算法(LS-FFT)作了对比研究。结果表明: 2-FFT算法运行速度最快, 4-FFT算法次之, LS-FFT算法速度最慢; 4-FFT算法对含有较强噪声和轻微欠采样的实验数据的处理效果是最好的; LS-FFT算法对强噪声数据的处理效果最差。

In order to recover the noisy wrapped phase map rapidly and accurately, four typical algorithms based on fast Fourier transform, i.e. the algorithms respectively based on four fast Fourier transforms (4-FFT algorithm), two fast Fourier transforms (2-FFT algorithm), four discrete cosine transforms (4-DCT algorithm) and combination of lateral shearing and Fourier transform (LS-FFT algorithm), are compared through theoretical analysis, computer simulation and experimental verification. The results show that, the 2-FFT algorithm is the fastest, followed by the 4-FFT algorithm, and the LS-FFT algorithm is the slowest. For the strong noisy and slightly under-sampled wrapped phase map obtained by digital holographic experiments, the 4-FFT algorithm performs the best, while the LS-FFT algorithm does the worst.