HDTV down-conversion using a drift reduction scheme

In the near future of the digital television (DTV) broadcasting, we assume that a standard definition television (SDTV) decoder should have the function of receiving a high definition television (HDTV) signal so that user with SDTV display can receiver HDTV program and display it on its monitor. In order to do so, it is required to convert a HDTV bitstream down to a SDTV signal. In this paper, we propose a fast and memory efficient scheme for the down-conversion. The proposed scheme uses adaptive scalar to truncate the HDTV motion vector for performing half-pel motion compensation (MC) in low-resolution so that the loss in motion vector accuracy will not be accumulated. It saves a lot of computations and requires a smaller memory by performing MC after the down-conversion. The simulation results show that the proposed scheme provides acceptable visual quality while maintaining reasonable complexity.