TY - CONF T1 - Video transcoding by reducing spatial resolution T2 - Image Processing, 2000. Proceedings. 2000 International Conference on Y1 - 2000 A1 - Yin,Peng A1 - M. Wu A1 - Liu,Bede KW - approach;computational KW - coding; KW - coding;video KW - complexity;data KW - compression;data KW - cosine KW - DCT KW - delivery;open-loop KW - domain KW - encapsulation;discrete KW - estimation;network KW - estimation;transform KW - hiding;digital KW - method;spatial KW - quality;motion KW - reduction;video KW - residues;MPEG KW - resolution KW - resolution;motion KW - stream;compressed KW - transcoding;computational KW - transforms;image KW - vectors KW - video;downsized KW - video;image AB - In network delivery of digital video, if the bandwidth required for a video is not available, the video has to be recoded at a reduced bit rate. It is highly desirable that the transcoding is carried out in real time while maintaining reasonable image quality. In this paper, we propose a fast approach to derive from an MPEG stream a new MPEG stream with half the spatial resolution. For the downsized video, we first generate from the original compressed video an improved estimate of the motion vectors. We then propose a compressed domain approach with data hiding to produce DCT residues by an open-loop method. The computational complexity is significantly lower than a number of previous approaches. Simulation suggests that our approach produces reasonable image quality JA - Image Processing, 2000. Proceedings. 2000 International Conference on VL - 1 M3 - 10.1109/ICIP.2000.901123 ER -