| 摘要 |
Rate control in a stereoscopic digital video communication system is accomplished by modifying the quantization level of P or B-frame data in the enhancement layer depending on whether the frame is temporally predicted (from the same layer) or disparity predicted (from the opposite layer). The invention can maintain a consistent image quality by providing additional quantization bits for disparity-predicted P-pictures, for example, where a P-frame may be encoded from a B-frame in the enhancement layer. The selected quantization level corresponds to an overall bit rate requirement of the enhancement layer. For disparity predicted P-frames, the quantization step size is modified according to the activity level of the frame being encoded in the enhancement layer, or of the reference frame, whichever is greater. Also, image quality is improved and frame freeze up is prevented during editing modes such as fast forward and fast rewind which require random access to the picture data. When the reference frame in the base layer is the first frame of a group of pictures (GOP), the corresponding enhancement layer frame will be encoded as an I or P frame instead of as a B frame to improve image quality and eliminate or reduce error propagation during random access. <IMAGE> |
