A Noisy Image Filtering Method Using Unidirectional Decaying Pulse Couple Neural Network

Abstract

A novel method is proposed to detect and filter pepper and salt noise in an image based on Pulse Coupled Neural Network (PCNN) firing matrix, which contains the spatial information and time information of the original image. The PCNN structure is simplified to avoid selecting too many parameters, which a unidirectional decaying threshold is proposed. The pixels polluted by noise are detected through analyzing and processing the PCNN firing matrix then the noisy pixels are filtered by median filter, which is proved to be effective in removing pepper and salt noise. The window size of the filter and the filtering time for noisy pixels are adaptively determined by calculating the noise intensity of the contaminated image. The experiment result demonstrates that the proposed method illustrates better performance in removing noise while conserving image edges and details than traditional filter does.