Motion-compensated conversion from interlaced to progressive formats

Abstract

This paper presents a new system for the conversion of interlaced formats to progressive ones. Like other proposals, it is motion compensation-based, but a substantial 2-fold improvement is added. First, assuming translational motions, the problem in the vertical direction is studied as a generalized interpolation problem. As a result, we derive two sets of linear filters which take into account the aliasing existing inside the fields. The first set of filters allows one to efficiently perform the interpolation which is required for subpel motion estimation. The second set of filters improves the estimation of the lines needed to obtain the progressive format, namely the deinterlacing process itself. Second, an improved block matching algorithm based on a split and merge procedure is used to estimate the motion and correctly propagate the motion vectors from blocks with reliable motion to blocks with uncertain motion. In order to tackle the problem of covered/uncovered objects, the whole process of estimation and motion-compensated interpolation is applied forward and backward. Simulation results and objective measurements are provided for artificially moving interlaced sequences obtained from a fixed picture and for a progressive sequence first converted to interlaced. The global system has also been tested on other sequences and visually assessed.