Abstract: Salt and pepper noise is produced at the processes of collection and transmission of digital image. Traditional filtering algorithm can not remove the noise effectively in the high noisy rate. This paper presents a filtering algorithm with accurate noise pixels detection based on extreme and medium filtering algorithm. The algorithm distinguishes noise pixels and signal pixels through setting threshold value and considering the correlativity of adjacent pixels, so it can improve the precision of filtering. Simulation results show that this algorithm is better than other algorithms at filtering salt and pepper noise and preserving the detail of image. And the restoring effect of image is good under high noisy rate.

Key words: salt and pepper noise, noise pixel detection, median filtering, correlativity of pixels

摘要： 数字图像在采集、传输等过程中会产生椒盐噪声。传统滤波算法在高噪声率情况下，很难对图像进行有效处理。该文在极值中值滤波的基础上，提出一种具有精确噪声点检测步骤的滤波算法，通过设定阈值并考虑相邻像素的相关性来区分噪声点和信号点，提高滤波精度。实验表明该算法在滤除噪声并保护图像细节方面比其他算法有较大提高，在严重噪声污染情况下，对图像的恢复也有较好效果。

关键词: 椒盐噪声, 噪声检测, 中值滤波, 像素相关性

CLC Number: 

• TP391