关键词: 图像滤波, 椒盐噪声, 中值滤波算法, 灰度最值, 方向纹理, 概率滤波算法

Abstract: In order to detect and filter the noise more efficiently, the probability filtering algorithm based on the maximum and minimum gray and the directional texture detects the noise based on the maximum and minimum gray. For the suspicious noise of detected, it does second noise detection based on the smooth transitivity of four directional texture. In the filtering window, the signal pixel of highest frequency replaces the noise. If there is no signal pixel in the window, in order to make the window contain signal pixels, the filter window is enlarged. When the filtering window is enlarged to the maximum size, and there is still no signal pixel in the window, the pixel of highest frequency and processed in the window replaces the noise. The proposed algorithm and the current median filtering algorithms, the filtering performance of which is the best, are applied to image filtering experiment. Compared with the current median filtering algorithms, through the comparative analysis of subjective visual effect and objective data of the image filtering results, the probability filtering algorithm based on the maximum and minimum gray and the directional texture has proved that, its filtering performance is better than other algorithms. It maintains well the edges and details of image while filtering effectively the noise.

Key words: image filtering, salt-and-pepper noise, median filtering algorithm, maximum and minimum gray, directional texture, probability filtering algorithm