Salt & Pepper Impulse Noise Removal using Adaptive Switching Median Filter

Abstract

An effective median filter for salt & pepper impulse range signals. An additive noise process may corrupt these noise removal is presented. This computationally efficient filtering digital images in both the acquisition and transmission stages. technique is implemented by a two pass algorithm: In the first Application-specific image filtering algorithms are needed to pass, identification of corrupted pixels that are to be filtered are simultaneously remove the effects of the corruptive process perfectly detected into a flag image using a variable sized detection window approach; In the second pass, using the and preserve important features of the images. Impulse noise detected flag image, the pixels to be modified are identified and removal in image processing often involves the removal of corrected by a more suitable median. Experimental results show these salt and pepper noises from images which is a very that the proposed algorithm performs far more superior than important pre-processing step for most other subsequent many of the median filtering techniques reported in terms of processing tasks such as edge detection, segmentation and retaining the fidelity of the image highly corrupted by impulse classification. In this area, early advances were dominated by noises even to the tune of ninety percent impulse noise. The linear filtering. They have had enormous impact on the proposed algorithm is free from patchy effects, does not extend lmelterf They techad formous stationary black or white blocks in the image as has been found in many development of various techniques for processing stationary other adaptive median based techniques and is very effective in and non-stationary signals. However, there are a large number cases when images are corrupted with large percentage of impulse of situations where linear filtering approach performs poorly. noises. This algorithm works very well for images with lower The limitation is the inability to simultaneously eradicate noise percentage of impulse noises also.

An efficient LOF-based long-range correlation filter for the restoration of salt and pepper impulse corrupted digital images

“…We use the impulse correction phase of one of our previously published work, adaptive switching median filter (ASMF) [10] The proposed restoration algorithm is described in the following steps:…”

“…However, their performance was inefficient due to the large number of arithmetic calculations needed for obtaining the transformed image. Numerous switching schemes [6][7][8][9][10][11][12][13][14] also evolved by identifying the corrupted pixel positions and by replacing them with suitable values determined from detected uncorrupted pixels. Mu et al [15] proposed * Correspondence: justin var@yahoo.com a fast and efficient median filter (FEMF) by addressing the limitation of the adaptive switching median filter [10], but it failed to preserve structural details of the local neighborhood while restoring impulses.…”

Fast averaging peer group filter for the impulsive noise removal in color images

“…In that case the size of the filtering window has to be increased until at least 2 uncorrupted pixels are found. This procedure is widely used when denoising grayscale images contaminated by strong salt & pepper noise [92][93][94].…”

Study and Analysis of Impulse Noise Reduction Filters

“…Switching Median impulse filter [23] identifies the noisy pixels by testing them for corruption with a more acceptable noise detector and replaced by a much valid intensity that can keep up the image fidelity to a large extent. The impulse detector is found from among the reliable pixels of window whose dimensions vary adaptively with the noise ratio which cannot cause the misdetection of signal as noise.…”