Multichannel M-filtering for color image restoration

A new multichannel filter, the vector Huber filter (VHF) is proposed which, by relying on multivariate estimation theory permits to simultaneously remove impulsive and Gaussian noise from color images, while preserving edges and other fine image details. The new filter is obtained by extending the classical gray-scale Huber filter to the multichannel case. By relying on robust estimation theory, the rationale behind the development of the new filter is discussed. An approximated version of the vector Huber filter (the A-VHF filter), is also introduced to reduce the computational burden and making filtering practical. The validity of the A-VHF filter is confirmed by the preliminary experimental results shown in the paper.