基于高斯核函数离轴数字全息零级像的抑制

Suppression of the zero-order image in digital off-axis holography based on Gaussian kernel function

为了降低离轴数字全息的再现像中零级像对再现像的干扰,提出了一种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全息图来抑制零级像的方法。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。把该方法与现有的频域法、减全息图均值法以及减局部均值法在抑制零级像的效果和计算速度上进行了比较,证明了该方法抑制零级像的效果好,计算速度快。通过所采用的方法提高了离轴数字全息再现像的质量。

A new method to suppress the zero-order image by processing digital hologram with Gaussian kernel func- tion in spatial domain is proposed. First, an original hologram is filtered by Gaussian kernel function. Then, the original hologram decreases the filtered hologram to suppress the zero-order image. It is correct and effective to suppress the zero-order image by experiment. Compared with the methods of the hologram subtracts its mean, the hologram subtracts its local mean and frequency domain, the new method has a better and faster effect. The proposed method improves the quality of digital off-axis holography reconstructed image.