Abstract: Aimed at the loss of image details caused by median filtering when removing the impulse noise, this study proposes an adaptive filtering method based on noise detection and dynamic window. Firstly, using BDND method, the image pixel is divided into signal points and suspected noise points to reduce the number of pixels that need to be processed. Then a method of the window adaptive noise detection is designed to further distinguish the suspected noise points into the noise points and the fine points, which strengthen the protection of the details of the image. Finally the detected noise is removed by an improved adaptive median filter. The window adaptive control is integrated into this filter algorithm. The size of the window can be adaptively adjusted according to the noise condition. The image details are protected as much as possible while removing the noise. The experiments show that the algorithm in this paper is superior to other conventional algorithms in noise removal and detail protection, and can effectively improve the peak signal to noise ratio of the image. This method can also obtain better denoising effect for images with high density noise.

Key words:  impulse noise, noise detection, adaptive window, noise removal