Image Processing Of ROI Based On VxWorks Embed System

With the increasing use of multimedia technologies and development of Internet,image compression requires higher performance as well as new features. But current standards JPEG could not meet any more these equirements. In order to satisfy application in the 21st century, a new standard for the compression of still image, the JPEG2000,has been developed by the ISO/ITUT. It is not only intended to provide rate-distortion and subjective image quality Performance superior to existing standard, but also to provide functionality that current standards can either not address efficiently or not address at all. The difference between JPEG and JPEG2000, is that JPEG's coding system use Discrect Cosine Transform(DCT),but JPEG2000 use Wavelet Transform (WT)based multiresolution analysis.The Joint Photographic Experts Group (JPEG) is currently working towards the definition of the next still image compression standard called JPEG2000. Besides the use of a more efficient state-of-the-art technology to address the problem of compression as in the JPEG algorithm, care has been taken to provide in an efficient way multiple other functionalities insufficiently or not covered in JPEG, useful for today's and tomorrow's applications. The funtionality of interest in this paper is region of interest coding, which is introduced below. In many applications where digital images are involved (medical, remote sensing, etc.), there exists within the image, one or more regions of greater interest than the rest. By allowing the background (BG) to be coded with lower fidelity than the regions of interest (ROIs), significant gains can be achieved in terms of compression and hence in storage space and transmission times.This article's contribute is to do some research on JPEG2000 standard, especially ROI arithmetic based on VxWorks embed system, show us the base theory of JPEG2000, and analyses the every modules in the JPEG2000 encoding/decoding system. In the article,you can learn ROI 's principle and ROI's "fast arithmetic--MAXSHIFT". You also can see the ROI 's effect in this article and the improved rithmetic of ROI.