基于阶跃响应的4f系统逆滤波去噪方法

Inverse Filtering Denoising Method for 4f System Based on Step Function Response

针对目前常规器件构成的4f信息光学系统空不变性能不足的问题,为在现有条件下对4f信息光学系统使用逆滤波方法现实去噪提出一种改进方法。该方法利用光学系统的并行优势,通过一次光学实验获取所有输入点扩散函数的组合信息——系统的阶跃响应,再利用线性性质对输出图像进行逆滤波去噪。实验结果表明,该方法在现有常规器件条件下实现了逆滤波,能明显改善4f系统输出图像质量并很好的保留凸显细节信息,并且不增加光学试验的复杂度和时间,同时还可以降低后期逆滤波算法的复杂度,节省计算时间。

Since the 4f optic information system composed of general equipments has not enough space invariant character, an improved method is presented to achieve inverse filtering denoising under the general condition. The step function response is obtained by taking advantage of the parallel processing of the 4f system and the linear theory is used to realize the inverse filtering denoising of the output image. Experiments show that the method can achieve the inverse filtering denoising, remarkably improve quality of the optic image and keep the detailed information under the current condition. Furthermore, the method doses not increase the complexity and time of the optic experiment. At the same time, it decreases the complexity and time of calculation of inversing filtering.