A Morphological Approach to Remove Salt and Pepper Noise in Images

In this paper, a morphological approach based on pixel connectivity is proposed for removing impulse noise in images. Impulse noise, also called the salt and pepper noise, usually occurs in dark and bright regions of the image and the presence of this noise degrades the visual quality of the image by affecting its texture and fine details. Our algorithm first identifies the noisy pixels in image based on 4-connectivity between the processing pixel and adjacent noisy pixels in a chosen window. Based on the region on which the processing is being done, the identified noise is removed and a median filter of varying mask size is used for estimating the correct value. The proposed method is found to be effective in dealing with high density impulse noise and further all the fine details and texture of the image is preserved.