Abstract: An adaptive filter to remove mixed Gaussian noise and impulse noise of the corrupted images based on their minimum entropies was proposed. The proposed filter calculated the noise rate of the corrupted image based on the minimum local entropy, and utilized the noise rate to determine the size of filter windows and the number of pixels to be brushed off in the filter windows of Alphatrimmed mean filter, and then used the average of leaved pixels' gray as the output of the filter. The performance of the proposed filter was evaluated by experiments. Experimental results show that the superiority of this filter including the ability of removing noises and that of preserving the partial details of images in comparison with some existing methods (median filter and mean filter), and this filter is an adaptive Alpha-trimmed mean filter.

Key words: mean filter, median filter, filter windows, adaptive filter

摘要： 提出一种基于图像最小信息熵的自适应滤波算法，利用局部信息熵最小的办法估计图像中的噪声感染程度，从而自适应地确定修正后的Alpha均值滤波器中滤波窗口的大小和去掉灰度最大和最小的像素个数，然后进行滤波。实验结果表明此算法较现有的中值滤波和均值滤波器的滤波能力有显著提高，而且在图像的局部特征和细节保持方面优于现有的滤波算法，并克服了修正后的Alpha均值滤波器非自适应性的弱点。

关键词: 均值滤波, 中值滤波, 滤波窗口, 自适应滤波器