A New Coding Method For Low Bit-Rate Video Signals
Gang Tu, Luc Van Eycken, A. Oosterlinck · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1989
In this paper, a hybrid motion evaluation coder for low bit-rate (64 Kb/s) video sequence transmission is studied. More than one previous frames are used to estimate the temporary motion behavior in the motion evaluation process (rather than conventional motion estimation methods in which only the immediate former frame is used). The motion sequence is therefore estabished alongside the image data sequence. Through investigating and analysing the previous frame of this motion sequence, which are available to both the coder and the decoder, the moving objects can be identified from the background. The current image frame to be encoded is then divided into two types of regions: the background region which may not he transmitted at all but simply repeated with the data of the previously decoded frame, and the moving region which is encoded by compensating the motion information. The moving region is reconstructed in the normal frame sampling frequency while the background data are treated coarsely by refreshing them in a much lower frequency. The relative impact of the moving region with regard to the background region is also evaluated for assigning bits to the two separated regions. As long as this impact is significant enough, the background data may remain unchanged. The final reconstructed image frame is then the coarsely processed background superimposed by the decoded moving objects.