Intel Xscale270 Platform And Embedded Linux-based Image Acquisition System Design

Industrial monitoring system of embedded Linux provides uniform and flexible solution. It becomes possible to realize remote monitor and image gather by making use of embedded Linux system. Due to this point, the thesis aims to gather, compress, send and receive images by USB camera supported by Linux on the platform of embedded Linux system. Favorable performance and cheap price make USB camera broadly used. Meanwhile, it becomes the first choice for most monitering equipments by its features of flexibility, convenience and easy to install in embedded system. USB's driving programe is completely accordance with the driving rules of general equipments, and the core of standard linux also provide some special API functions, which is convenient to drive register and destroy itself.This thesis, at first, introduces pxa270 platform based on embedded Linux system and the software conditions of developing on the platform, especially, configuring software conditions needs to be stressed on. Next, it discusses in detail about how to realize gathering image on this platform and gives a concrete introduction for the implementation of video gather program including gather, compression and transfer, then at last, complete the transplanting from application programe to aim platform and the receiving program of the client end. On the other hand, the essay mainly introduces vedio4linux supporting USB camera in developping board Linux core. Chip will have specific treatments for different cameras. Gathering and playing video in time will be realized by using API of Video4Linux. On the other hand, gathering and transferring images will be completed through websever program and the image receiving will be realized by Java applet program.On the basis of changing codes, the compression of image comprehensively adopts both DCT and Huffman Code to reach a good effect. The system directly connects with net through the video taking by USB camera and MPEG-4 compression code. Then the users can examine the remote video image by standard net brower and media player program. By using the compression function, jpedlib code put digital image into jpeg file header and compress the data so that we'll get the data information we planned to show you.It also needs to handle the thread programming and transplanting the program of arm developping board, both of which are the important techniques in embedded linux.