The Research And Realize Of ROI Techniques In The Still Image Compressing Standard JPEG2000

Computer is more and more applied to process image and other multimedia, how to compress image effectively for saving resource becomes a research hotspot at present.Many international standards are designed for image compression, JPEG2000 is the newest standard of static image compression. JPEG2000,the new ISO/ITU-T Standard for still image coding, had been finished at the end of 2000.The difference between JPEG and JPEG2000 is that JPEG2000 use Discrete Wavelet Transform(DWT) as the main coding method.Region Of Interest coding is one of feature of JPEG2000,To maintain the image quality during the image compression is also a difficult problem .People often interest in some part of the image and neglect other part of it ,which is the Interesting Region Coding Thought. With this thought we can obtain the balance between the image compression and image quality, reaching excellent compression effect on the basis of keeping the image quality.The paper focuses on the JPEG2000 standard discussion and Interesting Region Coding Thought, and according to the actual situation proposes one method which can reduce the complexity of encoding and reach Interesting Region Coding effect. The paper analysis the image compression standard of JPEG2000 for the generality, describe the ROI coding of JPEG2000, In the same time,the author briefly introduce wavelet theory which is the basis of the discrete wavelet algorithm adopted by JPEG2000,analysis the algorithm of ROI based on Discrete Wavelet Transform.Finally the author carry on the detailed analysis to EBCOT algorithm and to the multiple ROIs method,analysis every block of encoding,proposes one coding algorithm of ROI based on EBCOT and proposes one method can realize image Multiple ROI and Multiple Quality compression. This method embarked from the practical application characteristic, carried on first the rank arrangement to Multiple ROI, and filtered the high frequency component that the background region outside the ROI thus reduced the JPEG2000 code operand, reduced the production symbol stream code time. At the same time, this method had not any request to decodes, had used the JPEG2000 core code algorithm, has more advantageous to the realization and the maintenance compatibility.