The Research On Application Of Rate Control In Embedded Image Coding

Digital image needs a mass of data, while the image data is highly related, including redundant data. The image can be compressed effectively via removing these redundant data without harming positive information, the digital image compression is designed to solve the problems of the image size, the image storage and the image transition.This article is using the application which take the high quality image the hardware realizes as a goal, studiing the JPEG 2000 compressed encoding process, carries on widespread and the thorough analysis and the discussion to its algorithm.In the above foundation, base on the characteristic which realizes according to the hardware, made own some optimization plans: Obtained from post compression rate distortion, usning one kind of new difference interrupt processing algorithm, remove the repeated process which the original algorithm in possibly produced, simplified the hardware implement, reduced to the hardware memory's request, but the picture quality reduceed unobviously. In the optimized code rate control's binary search methoed in coding stream , used relative rate to replaces tagtree coding part in the original algorithm which need processed many times, enhances hardware's parallelism. In the multianalysis JPEG 2000's EBCOT T2 encoder's tagtree principle, understood it difficulty in implement, after control the size of code block which come from wavelet transformation to simplifies the tagtree coding algorithm in hardware implement, the coding stream form which it produced still according the JPEG 2000 coding stream standards, but simplifies the tagtree's hardware implement, may also reduce the massive memories. Has analyzed the JPEG 2000 information head's format, solidifies the method to the specific image's information head's hardware code use to realize, skip the information codeing part. Through the above several optimized methods, may enhance hardware's degree of parallelism, reduces the hardware to difficulty of implement, reduces the storage space, but the quality of compressing picture is control in acceptable scope.According to the JPEG 2000 standards, the different parameter has the diffenent influence on final image's coding stream's length, in the specific image compressing condition, through mathematics regression analysis's method, summarizes a regression formula, useing this formula to forecast interrupts position in the final code block of the symbol stream, has realized one kind of real-time code rate interruption algorithm. After using this algorithm to substitute original JPEG 2000 post compression rate distortion, may reduce in obviously the original algorithm the massive calculations, thus raises system's running rate.In the finally,the problem requiring further studies are discussed.