Design Of Real-time License Plate Recognition System Based On DSP

With the development of the transportation, Intelligent Transportation System (ITS) is widely used in transportation management. What's more, License Plate Recognition (LPR) is the key technology of ITS. The image data collection and the License Plate Recognition algorithm are the two parts of the LPR. With the rapid development and excellent performance of DSP, a new video capture and processing system come out to meet this requirement, which consists of a kernel DSP and logic controller element(CPLD or FPGA)as the main structure.After studying the technologies and theories of DSP deeply, we choose the TMS320C6713 of TI to design a video image processing system based on DSP. The system is mainly based on the features that DSP is handy, cheap and stable. TMS320C6713 is a kind of high-powered floating-point digital signal processor, and it has powerful hard structure, soft system and high computing speed of 225MHz, so it works as the central processor to process the images in the system. This system includes video input, video output, circular memory, logic control and etc. This system is different from the traditional image processing system based on PC mode in character, improve its performance in the field of real-time than ever and reduce the cost of the system in most possible. At the same time, the traditional Double-SRAM buffers are used for video input and output, the logic-control element is a FPGA. We use VHDL language designing the FPGA logic, achieved the harmonious operation of the different parts. Compared to the current same-type system, this system is simpler in structure and cheaper in cost.The whole thought of this design, the work principle and concrete procedure in detail of every module is introduced in the dissertation. At last, we design the median filter arithmetic for the system to test the relative quality of the system, which obtains the desired properties.Finally, the dissertation summarizes the shortage of the system, take the method to modify and introduce the prospect of the system in the future.