An Efficient and Simple Switching Filter for Removal of High Density Salt-and-Pepper Noise
Hani M. Ibrahem · International Journal of Image Graphics and Signal Processing · 2013
This paper presents an efficient and simple adaptive method for high density salt-and-pepper noise removal.A noise detector is utilized to check whether the selected pixel is noisy or noise free.Noise pixels will then be subjected to the second stage of the filtering action, while the noise free pixels are left unaltered.Since not every pixel is filtered, undue distortion can be avoided.The noise free pixels are only considered in the filter operation for finding the value of the processed pixel.The window size is selected as 3 X 3 in the first step.If all pixels within the window are considered to be noise, then change the selected window size to 5 X 5.If all the pixels within the selected 5 x 5 window are considered to be noise, then the processing pixel is replaced by the previous resultant pixel.This technique requires one nonnoise original image as training image.The key point of the filter operation is based on the solution of the equations system X=A -1 B in the nonnoise original image.An algorithm to extract the data from the nonnoisy image and form it in the linear equation system is presented.Comparison of the given filter with other existing filters is provided in this paper.The results demonstrate that the proposed technique can obtain better performances than other existing denoising techniques.The proposed method works well for high-density salt & pepper noise even up to a noise density of 97%.