Nonlinear filtering by threshold decomposition

A new threshold decomposition architecture is introduced to implement stack filters. The architecture is also generalized to a new class of nonlinear filters known as threshold decomposition (TD) filters which are shown to be equivalent to the class of Ll-filters under certain conditions. Another new class of filters known as linear and order-statistic (LOS) filters result from the intersection of the class of TD and Ll-filters. Performance comparison among several filters are then presented. It was found that TD is compatible with Ll, LOS, and linear filters in suppressing Gaussian noise, and is superior in suppressing salt-and-pepper noise. LOS filters, however, provide a better compromise in performance and complexity.