The DSP Technology For Anti-leakage Of Video Information

This paper firstly discusses the actuality and trend of the electromagnetic information leakage and analyses the mechanism of the electromagnetic leakage in a computer system. Secondly the paper develops two new techniques that enable the software on a computer to control the electromagnetic radiation of CRT monitor transmits at very low cost: digital filter and dithering technique. The two new techniques are completely different from the classic ones for anti-leakage of video information, who can overcome many disadvantages of the classic techniques,such as high cost and low performance. Thirdly the paper validates the two methods to reduce the information leakage by a experiment and gives a little mend. The digital methods are very effective but if the methods are implemented only by software, the performance of computer shall be influenced badly. This paper gives a new method which combines the software with hardware. All the operation can be completed only by the DSP system quickly, thus the real-time request can be satisfied and the performance of CPU isn抰 depressed. Lastly, this paper give a detailed description about the design of the DSP system, which is based on the TMS320VC549, including image collection, image manipulation and image display.