Random-valued impulse noise detector based on minimum spanning tree and its application to switching median filter

A switching median filter is effective for the impulse noise elimination while preserving edges and details of an image. In the switching median filter, an impulse noise detector is employed before filtering, and the detection results are used to control whether the pixels should be filtered or not. However, the conventional impulse detector tends to misjudge noise-free pixels constructing line structures to be the noises. In this paper, a new impulse noise detector based on the minimum spanning tree is proposed, and it is applied to the switching median filtering in order to eliminate the impulse noise effectively even for the image including line structures. Through the experiments, the effectiveness of the proposed impulse nosie detector is illustrated.