消除零级衍射和循环移位改善计算机合成全息图的再现质量

Improving Reconstruction Image Quality of Computer-Synthesized Hologram with Eliminating Zero-Order Diffraction and Circular-Shift

分析了影响计算机合成全息再现像质量的主要因素,提出了一种改善计算机合成全息再现像质量的方法。零级衍射严重降低了再现像的对比度,连续两次离散傅里叶变换的循环移位作用使得再现虚像最后一行和最后一列被分别循环移位到第一行和第一列。采用Burch型合成全息图再现算法消除了零级衍射,调整像素的位置消除了虚像的循环移位,使得全息图能够精确恢复原始图像,实验证明这种方法能改善再现像质量。

After analyzing the reconstructed image quality of the computer-synthesized hologram（CSH）,a method to improve the reconstructed image quality of the CSH is provided.The zero-order diffraction will decrease the contrast of reconstructed image,while the cyclic shift effect of twice Discrete Fourier Transform（DFT） will shift the twin image’s last row and last column to the first row and first column,respectively.Burch’s method is adopted to eliminate the zero-order diffraction,while the pixel location is adjusted to eliminate the virtual image cyclic shift,the original image of CSH can be reconstructed accurately.This method is effectively proved by experiments.