Research On Rate Control Algorithm For JPEG XR

Still image compression standard JPEG XR and Motion-JPEG XR motion picture compression standard have high compression performance, support for higher dynamic range and color accuracy, and fully use integer operations to simplify the algorithm and reduce memory footprint and so on, which make it in the near future be more widely used. Rate control algorithm is an important part in the JPEG XR encoding, which determine the merits of the image compression performance and image quality. Therefore, researching the rate control algorithm of JPEG XR, proposing high-quality rate control strategy can help reduce coding using redundant, reducing memory consumption and increase coding speed. They are very important for JPEG XR and Motion-JPEG XR.Before studying the rate control algorithm, we introduce compression standard JPEG XR image coding and image coding rate control of the basic theory first. This part of the presentation will provide valuable basic knowledge and theoretical basis for further study the rate control algorithm of JPEG XR. Then we according to the encoding characteristics of JPEG XR, propose a novel rate control algorithm which based on a adaptive rate-distortion table, it can adjust based on the current situation of the macro block coding. The method has low complexity and good image quality. To verify the performance of the algorithm, we compare it with a quadratic RD algorithm. The experimental results show that the proposed algorithm improves both in the control accuracy and quality of the reconstructed image.Finally, we introduced a full pipeline system structure of JPEG XR, and how to implement the pipelined rate control were analyzed. After analysis, we give out a solution of pipelined rate control module with little descend of performance, and simulate it in software for the performance. The results show that rate control module could be used in pipeline system with only 0.13% control accuracy and tiny image quality loss.