(A) variable bit amount allocation scheme for real time moving picture compression

Abstract

The optimal bit amount allocation in DVD (Digital Video Disc) application is to distribute a given bit amount over a set of sources such that the overall distortion is minimized. To meet this demand, two cycles of VBR (Variable Bit Rate) coding scheme is employed for optimal video coding in read only disc (DVD-ROM type) since a real-time signal processing is not required at the time of recording. Recently a rewritable disc such as a magneto-optical disc has made remarkable process in its recording capacity. This means that moving pictures can be recorded through the real time and the two cycles of coding for optimal bit amount allocation cannot be employed in real-time recording. In this thesis, an MPEG-based real-time variable bit amount allocation scheme, which utilizes the spatial information for the I-, P- and B-picture and the motion information for the P- and B- picture, is proposed to predict the bit amount of next picture. The proposed scheme for the real-time moving picture compression showed good performance in terms of SNR, and nearly the same performance as VBR control scheme using two cycles of coding targeting the optimal bit amount allocation. Because the spatial information and the motion information, which are used in the proposed scheme, are also required for the standard MPEG encoding procedure, the additional amount of computation for the proposed scheme is negligible for MPEG encoding.