基于小波变换的太赫兹数字全息再现像去噪研究

太赫兹数字全息是当今太赫兹成像领域的研究热点之一。以真实连续太赫兹同轴数字全息再现像作为研究对象,进行了基于小波变换的去噪研究。选用bior2.2和sym4两种小波基,分别采用硬阈值和软阈值方式,对全息再现图像进行小波阈值去噪和基于小波的同态滤波处理,然后定量分析去噪结果。实验结果证明,对连续太赫兹同轴数字全息系统记录的再现像,采用bior2.2小波基的基于小波软阈值去噪的同态滤波,对太赫兹同轴数字全息再现图的去噪效果最好。

De-noising research on terahertz digital holography based on wavelet transform

Terahertz digital holography is one of the research hotspots in the terahertz imaging field over the world nowadays. The real reconstructed image was used as the research object, which was achieved by the continuous terahertz inline digital holographic imaging system, and the de-noising research was studied based on wavelet transform. Wavelet threshold technique and the homomorphic filtering based on wavelet were applied to denoise the image, with hard threshold and soft threshold technique respectively, by bior2.2 and sym4 wavelet base. Then the denoising result was quantitatively assessed. The experimental results show that the homomorphic filtering based on wavelet has the best de-nosing performance for the reconstructed image of terahertz continuous inline digital hologram, which works with soft threshold method and the bior2.2 wavelet basis.