| Video technology has been improved and used diffusely in our living, because the technologies of micro-electronic, computer science have been developed in high speed. At the same time, DSP chip is used widely in video processing and transmission field, because it's integration density, computing speed and digital taking in and sending out rate is improved continuously. In this paper, a digital image impress system is described. Digital image compression technology is used in this system. It records the images of some certain locale and provides information for postmortem. This system has little volume and because has its own memory chip, it can be installed and used independently.The proposed system is composed of image taking, image compressing, image data storing and image data picking-up these four parts. CMOS image sensor is used in image taking part. CMOS image sensor is becoming gradually the principal product of image sensor, because the integration degree of the CMOS image sensor is high, and it can obtain digital image directly. TI 54 DSP chip is used in the image compressing part, and it is the hard-core part of the system. This part not only realizes the compression of the images, but also controls other chips in this system. For the background is unchangeable, this paper adopts DCT commutation with DPCM, RLC coding, and Huffman's coding arithmetic of image compressing, and gets favorable effect. The CF card is used as the memory of the image data storing part. We used CF card in the proposed system because it has the following merits, such as little volume, high dependability. The USB gateway technology is used in the image data picking-up part; This makes data reading simple and fast.
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