Abstract: According to excellence and shortcoming of conventional median filter algorithm，an algorithm called adaptive weighted median filter algorithm based on similarity function is proposed.The method works in this way：Firstly，noise detection is employed to determine noise points in image，then the size of filtering window is adaptively adjusted according to the number of noise points，and the pixels are adaptively grouped in an ingenious way based on the similarity and weight value of every pixels is calculated adaptively.Finally，a new weighted median image smoothing algorithm is used to filter noise pixels.The simulation experiment shows that this algorithm both may effectively eliminate the noise，and may protect image detail well.Therefore it has better filtering performance than the conventional median filter algorithm.

摘要： 针对传统中值滤波算法的优缺点，提出了一种基于相似度函数的自适应加权中值滤波算法。该算法首先通过噪声检测确定图像中的噪声点，然后根据窗口内噪声点的个数自适应地调整滤波窗口的尺寸，再根据相似度大小，巧妙地将滤波窗口内各个像素点按一定的规律自适应地分组并赋予每组像素点相应的权重，最后采用加权中值滤波算法对检测出的噪声点进行滤波处理。计算机模拟实验结果表明：该算法既能有效地滤除噪声，又能较好地保护图像细节，滤波性能比传统中值滤波算法更理想。