BBC R&D

Abstract

The conversion of interlaced video to progressive format may be carried out in a number of ways, including simple vertical interpolation, fixed or motion-compensated vertical-temporal interpolation, and approaches based on motion compensation using non-uniform sampling theory. Motion-compensated methods are the only ones which offer the possibility of maintaining high vertical resolution with minimal aliasing for the majority of vertical motion speeds. However, the accuracy and reliability of the vectors has a significant impact on the performance of such methods. For some applications, such as display conversion using vectors recovered from an MPEG-2 coded signal, the vector signal available will be less than perfect. This Report considers several motion-compensated interlace-to-progressive conversion methods, and assesses their performance with both accurate and inaccurate vectors. A way of making any motion-compensated method tolerant to gross vector errors is proposed and evaluated. Comparisons are made with non-motion-compensated methods, and a recommendation is made of a method suitable to use with vectors recovered from an MPEG-2 bitstream.