TWO-STAGE BUFFER CONTROL FOR CONSTANT QUALITY TRANSMISSION OF MOTION JPEG2000 VIDEO STREAM
| Autor: | Ke-Wei Chen, 陳科維 |
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| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 Motion JPEG2000 (MJ2) has recently received increasing attention for its high efficiency in intra-frame coding and salient features in streaming compressed data over lossy networks and time-varying channels. As an extension of the JPEG2000 image coding standard, MJP2 is virtually a stream format for organizing compressed frames generated by the baseline JPEG2000 coding engine. As in the case of image coder, MJP2 has also some unsolved problems in the implementation of coder even though the generation of code streams is clearly specified. Among these problems, the buffer control for reducing quality fluctuation across frames under changing content and varying channel bandwidth is most significant. In this thesis, a novel buffer control algorithm for MJP2 coding, which consists of two stages, is proposed to efficiently reduce quality fluctuation and memory usage. In the first stage, an average of distortion is computed from the frames that have already transmitted, the frame in transmission and the frames in transmission buffer which video frames to get consistent distortion. In the second stage, the overall bit number allocated in the first stage should not exceed the available space in the transmission buffer. In the algorithm, the lowest number of video frame buffers required for maintaining video quality at a given bit rate can be achieved. The goal is to allocate the capacity of channel between sequences to achieve constant quality across all sequence. Experimental results show that the proposed buffer control algorithm has higher performance in constant quality transmission than Motion JPEG2000 without buffer control. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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