(A) study on temporal filter based on motion adaptive spatial filtering and its systolic realization

Abstract

In this dissertation, a motion adaptive spatial filtering technique is discussed for a temporal band-limitation of video signals, and its systolic realization method is investigated. The proposed filter, named MASF (Motion Adaptive Spatial Filter), is based on the basic idea that a temporal filter can be specified on the spatial domain. Assuming that moving objects of an image sequence have constant velocity and rigid-translational motion, the temporal band-limitation is implemented by a space-variant spatial filter. In general, a sequence of images containing moving objects are known to bave inherently aliasing components. The proposed method has an important characteristic that the aliasing components can be reduced, which can not be achieved by conventional temporal filters. From a signal processing point of view, the aliasing degrades filter characteristics. Thus, the MASF is more preferable to the temporal domain filtering. To utilize the MASF in real applications, hardware realization scheme is proposed. By use of the systolic array well known structure for a VLSI design, systolic realization is investigated. The MASF is 1-dimensional convolution (1-dimensional transversal filter) along the movement trajectory. Considering the space-variant filter characteristics, the MASF is converted to 2-dimensional spatial filter suitable to parallel computing. The realization scheme permits modification of the filter window size without affecting to the throughput rate. For a real application, scanning types of an input source and filter structure should be considered. The former indicates Interlaced and Noninterlaced scannings, the latter is Finite Impulse Response (FIR) and Infinite Impulse Response (IIR). In this dissertation, they are fully discussed. Experiments based on the artificial and real image sequences present feasible results such as an improvement of coding rates and visual effects, etc. The MASF includes a wide scope temporal band-limitation, e. g., 3...