The Fast Analytical Research On JPEG Bitstreams

In this thesis,coding and decoding technology of JPEG is introduced as well as principles of these technology and data structure.According to the study above,the fast analytical research system on JPEG bitstreams has been developed.Based on the traditional JPEG decoding process as the entrance in the thesis,this paper presents a flow optimization code algorithm:when huffman tables used for decoding a normal JPEG image,the efficient representation of the code words in the final JPEG file decides the optimized effects of huffman table.In addition,the fast positioning method based on the MCU block query parsing has been proposed in order to obtain the specific decoding information of each MCU block.Using coefficient of color component in 8 X 8 units of image,this algorithm constitutes the specific MCU block rapidly and displays its specific code data.The software system has improved the traditional JPEG decoding process.At premise of keeping the rebuild pictures and the source pictures similar on the sense of vision,it performes the optimization on DHT,calculates the quantized DCT coefficients for all MCU blocks in the image,analyzes each 8×8 decoding information for the Y,Cb and Cr components.This paper has accomplished the studying which JPEG decoding control process based on DCT.It finds out JPEG data construction in-depth and makes an analytical report on this foundation.This thesis has implemented the fast analytical research on JPEG bitstreams and its optimized technology.The software offers a new preview and new decoding solution to the daily picture processing,such as Web picture downloading,data picture proofing,picture printing and so on.