基于希尔伯特变换的数字全息位相重构技术

为了提高数字全息重构的精度,采用希尔伯特变换的方法对数字全息位相重构进行了理论分析和实验验证。首先利用傅里叶变换滤除全息图中的0级项,然后运用希尔伯特变换对已经滤除0级项的全息图实现90°相移,并构造出解析信号,从而可以求出物体的包裹位相,最后利用最小二乘法进行位相解包裹得到物体的真实位相;并将希尔伯特变换法与常规傅里叶变换法重构的实验结果进行了对比和分析,获得了标准偏差的对比数据。结果表明,该方法比常规傅里叶变换法重构精度要高。这一结果对提高位相重构的精度是有帮助的。

Digital holographic phase reconstruction technology based on Hilbert transform

In order to improve the accuracy of digital holographic reconstruction, theoretical analysis and experimental verification of digital holographic reconstruction phase were made by using Hilbert transform. Firstly, the zero order item of the hologram was filtered through Fourier transform. Secondly, the hologram without zero order item was shifted 90° through the Hilbert transform so that the analytic signal was constructed and the object's wrapped phase was found. Finally, the object's real phase was obtained by using the least square method to unwrap the phase. The experimental results of Hilbert transform reconstruction and conventional Fourier transform reconstruction were compared. The data of the standard deviation was obtained and compared. The results indicate that the reconstruct precision of this method is higher than the conventional Fourier transform method. The research results are helpful to improve the precision of the phase reconstruction.