Adaptive Rank Based Impulsive Noise Reduction in Color Images

In this paper a new approach to the problem of impulsive noise removal in color images is presented. The novel design can be seen as a generalization of the vector median filter and is based on the weighting of the dissimilarity measures between pixels contained in the local filtering window. The weights assigned to each color sample are decreasing functions of their ranks in an ordered sequence, while the ordering is based on the distance between a given pixel and its neighbors. In this way, the rank weights diminish the influence of outliers on the proposed filter output. Extensive experiments revealed that the new filtering design efficiently suppresses the impulsive noise corrupting color images while enhancing their edges. This unique feature can be utilized in any application in which noise removal combined with edge enhancement is desired.