The Analysis And Implementation Of Image Compression Algorithm In Application Of Visitors’ Safety Management System

With the development of science and technology as time goes, digital image is becoming more and more important in the information world, and they are widely applied in various fields now. In the "visitor safety management system based on dynamic information collection connecting to the CCIC platform", after visitors’information being collected, they have to be stored into local DB, and transmitted from client to server. Image information such as visitor’s photo, is a very important part because by using the image information, the comparison can be more accurate between the visitors’information and the criminals’information in the CCIC Library, in order to make sure that the security for departments, institutions or agencies and some other closed areas with the system.However, because of the file size of collected visitors’information is too big, there’s a problem in visitors’information storage and transmission. This is an urgent problem to be solved. Therefore, our storage space and transmission bandwidth is limited, so it’s quite important to choose a suitable algorithm for image compression, not only to make the compressed image smaller in size so as to reduce the storage space, but also to ensure the quality of the image, so that it can be effectively used in the comparison between visitor’digital image information and CCIC Library image information. These are the points of this paper.During the developing process of digital image compression, there are kinds of image compression method invented. At present, the EZW (embedded zero-tree wavelet) algorithm is widely applied because of its superiority in many aspects. SPIHT algorithm improves the sorting of important coefficient table comparing to EZW algorithm, so that the sort process and scan process is more brief and efficient, which leads to the improvement in the general compression efficiency. According to the "visitor safety management system" requirements, this paper intends to find a proper digital image compression method which can deal with numerous kings of images. This method have to be good at both compression speed and quality to meeting the requirement of compression rate.In this paper we do some research of several popular image compression algorithm, make theory analysis, compare their characteristics, and at last select the most suitable algorithm of this system. They are tested by this way:using these algorithms for image compression experiment, and record their own statics, then make a comparison between them. The final choice is made according to the specific system requirements, and from the analysis of the experimental results. We consider both efficiency and quality to judge on which is the most proper algorithm for digital image compression function of this system.