In the new m ethod, the traditional Wiener filter is used at first to obtain the initial esti mate of the target image, based on which the spectral densities of the target im age and noise image are estimated.

• 在改进的方法中 ,首先采用传统维纳滤波方法求得初始估值 ,然后利用该初始值求得原图像及噪声的谱密度估值 ,进而利用这些新获得的信息构成改进的维纳滤波器对退化图像进行第二次滤波。