一种新型的自适应模糊中值滤波算法

New adaptive fuzzy median filtering algorithm

针对传统中值滤波算法不能很好地保护图像细节以及受严重噪声污染时性能急剧下降的情况,提出了一种新型的自适应模糊中值滤波算法。通过比较滤波窗口内像素点的灰度值与像素点灰度值的均值定义了模糊滤波系数,利用此模糊滤波系数对滤波方法进行加权,得到一种加权中值滤波器。通过对小窗口内的灰度值不等于最大灰度值和最小灰度值的像素点的检测自适应调整窗口大小,对超过设定的最大窗口的情况,噪声点的灰度值用四个相邻的已处理的像素点灰度值的均值进行替换。仿真结果表明,新算法具有较好的细节保护能力和较强的去除噪声能力。

A new adaptive fuzzy median filtering algorithm is proposed for the problem that traditional median filtering algorithm can’t protect the image detail very well, and that its performance will be in the sharp decline in dealing with high-density noise image. By comparing the gray value of the pixels and the mean gray value of the pixels in the filtering window, coefficient of the fuzzy filter is defined. By using this coefficient as the weight function, a new weighted median filter approach is proposed. The size of the window is adjusted automatically by detecting the presence of pixels that have gray value between the maximum gray value and the minimum gray value of the filtering window. The gray value of the pixels in the center of window which exceeds the maximum window is replaced with the mean of gray value of neighbor-ing four pixels. Simulation results demonstrate the new algorithm has better image detail preservation and strong denois-ing ability.