Image restoration by multistage adaptive center weighted median filters
Tong Sun, Moncef Gabbouj, Yrjo A. Neuvo · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1994
Multistage data-dependent center-weighted-median (CWM) filters, which contain a cascade of several adaptive CWM filters based on local statistics, are presented in this paper for image restoration. Window shapes on different stages, which are oriented in different important correlation directions of images, can be different. The selection of a window shape on each stage provides additional flexibility for the design of filters in order to improve the filtering performance. One important merit of the method is to remove noise in all regions of images, including detail regions, but still preserve the details. The performance of the proposed filters is better than the corresponding 2D single-stage filters with the same window size in many cases. Computer simulations are provided to asses the performance of the proposed filters.