On the extraction of DC sequence from MPEG compressed video

Abstract

Reduced images formed from the collection of DC coefficients in intra-coded DCT compressed video retain a "global" feature which is useful for processing purposes. This paper examines the direct reconstruction of such DC images from motion-compensated P-frames and B-frames of MPEG compressed video. Exact expressions are derived and approximations are given for the computational speedup. The analysis and experimental results show that the approximations yield images that are very close to the true ones.