半导体光电, 2014, 35 (4): 745, 网络出版: 2014-09-01
反射式离轴数字全息再现像中的噪声抑制
Noise Suppression in Reflective Offaxis Digital Holographic Reconstruction
全息 零级像 散斑噪声 高斯核函数 非局部均值滤波 holography zeroorder image speckle noise Gaussian kernel function nonlocal means filter
摘要
为了抑制反射式离轴数字全息再现像中的零级像和散斑噪声对再现像的影响, 利用高斯核函数在空域对数字全息图进行低通滤波, 再用原数字全息图减去滤波后的低频信息来抑制零级像, 采用非局部均值滤波来抑制散斑噪声。实验结果表明空域高斯核函数处理法能有效地抑制零级像, 非局部均值滤波可以抑制散斑噪声但对部分细节的保持能力不强, 改进后的非局部均值滤波在抑制散斑噪声的同时能很好地保护细节信息, 提高了离轴数字全息再现像的质量。
Abstract
To suppress the zeroorder image and speckle noise in reflective digital offaxis holography which have great impacts on the quality of reconstructed images, proposed is a new method, in which, firstly, the digital hologram is processed with Gaussian kernel function in spatial domain, then the original hologram is used to decrease the lowfrequency information of the filtered hologram so as to suppress the zeroorder image, lastly, a nonlocal means (NLM) filter is proposed to suppress speckle noise. Experimental results show that it is correct and effective to suppress the zeroorder image by processing digital hologram with Gaussian kernel function in spatial domain and NLM filter can only suppress the speckle noise effectively. While the improved NLM filter can not only suppress the speckle noise, but also preserve details perfectly, so the quality of reconstructed image is improved effectively.
汤春明, 张洪科, 于翔, 刘玉翠. 反射式离轴数字全息再现像中的噪声抑制[J]. 半导体光电, 2014, 35(4): 745. TANG Chunming, ZHANG Hongke, YU Xiang, LIU Yucui. Noise Suppression in Reflective Offaxis Digital Holographic Reconstruction[J]. Semiconductor Optoelectronics, 2014, 35(4): 745.