Multivariate MTM filters-analysis and design options

The modified trimmed mean (MTM) filters are known to possess desirable robustness and detail preservation properties. They combine the averaging operation with the median operation which implies that the filters also attenuate noise efficiently. We investigate multivariate extensions of the MTM filters. In the multivariate case, there is no unique way to define the MTM filters and hence there are several design options. A few of the most promising definitions for these filters and various design options are studied. The robustness of multivariate MTM filters is analyzed using the influence function approach. Filtering examples are also given using RGB color images