Research On Rate Control And Quality Assessment Based On Structural Distortion Measurement

H.264/AVC video coding standard is provided formally by JVT(Joint Video Team)in March,2003.It is thought as new generation video compression standard because of its outstanding performance.The standard supported very low bit rate video-on-demand services etc.So this standard obtains much attention from academic and industrial fields.Rate control,which is an important part of video compression,controls bit rate of video compression.Quality and transmission of video is subject to rate control algorithm whatever the video coding standard is.It is very important to control video coding in order to obtain optimal compression under the constraint of transmission and computation power in real world.Several important issues for real-time video coding have been addressed in this paper.They are the analysis and regulation of the coding complexity,applicable rate control and video quality assessment.1.This paper discusses the principles of rate control and H.264 standard adopts many new tools to enhance the coding efficiencies,which are multiple reference pictures,variable block-size with seven block sizes in motion prediction, quarter-pixel accuracy for motion vector,short word-length integer transform,context-adaptive entropy coding and loop filter for deblocking.2.This paper reviews the classic rate control algorithm and points its problems.From the Software implementation of GO12,A relationship of PSNR and Bit rate has been reported. Subsequently a new algorithm is proposed to make general rate control algorithm more efficiently.Software implementation is given based on standard reference code JM86(Joint Model). PSNR and subjective quality of the decoded pictures is improved and actual bit rate is more close to the target bit rate.3.Based on structural distortion in the evaluation of methods fully taken into account the visual characteristics of the human eye - the human eye's main function is to extract images of the structural information.Experiments on the video quality experts group(VQEG) test data set shows that the new quality measure has higher correlation with subjective quality measurement than the other proposed methods.