Adaptive 3-D median filtering for restoration of an image sequence corrupted by impulse noise

Abstract

An adaptive 3-D median filtering, which achieves optimal image quality as well as fast computing time, is proposed to remove the impulse noise from a highly corrupted image sequence. The proposed algorithm is compared with the widely used impulse noise removal algorithms with respect to the peak signal-to-noise ratio and the number of computations. The proposed algorithm preserves the image details which are not expected to be corrupted by impulse noise so that the number of computations can be minimized. It has good restoration performance whether the number of pixels corrupted by impulse noise is large or small. In the proposed algorithm, the impulse noise ratio, which is the ratio of the number of pixels corrupted by impulse noise to the total number of pixels, is estimated, and the restoration filtering is adaptively applied based on the estimated impulse noise ratio.