Mixed domain filtering of multidimensional signals

The concept of multidimensional mixed domain transform/spatiotemporal (MixeD) filtering is extended beyond the discrete Fourier transform (DFT) to include other types of discrete sinusoidal transforms, including the discrete Hartley transform (DHT) and the discrete cosine transform (DCT). Two MixeD filter examples are given, one using the two-dimensional (2-D) DHT and the other using the 2-D DCT, to selectively enhance a 3-D spatially planar (SP) pulse signal. The authors define the notation and provide a review of the MixeD filter method. MD and partial P-dimensional discrete transform operators are defined, and the design of MixeD filters is discussed. MixeD filters based on the 2-D DHT and the 2-D DCT are designed to selectively enhance a 3-D SP pulse. Experimental verification of these 3-D SP MixeD filters is described