Traffic Signage Automatically Identify The Key Technologies Of The System

With the worldwide development of the intelligent traffic system, traffic sign automatic recognition, as a part of the development, is now receiving more and more attention from academe and traffic department. It is an important study project abroad, in China, however, there is no such a traffic sign automatic recognition system available now due to the late start of its development. Considering the actuality and the situation that Motorola has brought forward the plan of recognizing the traffic sign, we meet the challenge and begin to study traffic sign automatic recognition system.As a vision recognition system, the input data of the traffic sign automatic recognition system are images from the camera. By recognizing these images, the system can recognize the content of the traffic sign. In the thesis, images processed are all static because the input images in the project are static. The traffic sign automatic recognition system is composed of the following modules: image segment, camera calibration, characteristic curve extraction, three-dimension recovery and image matching. In the thesis, we mainly study these techniques.Image segment is the key technique for each vision system, and the base of image processing. In the thesis, emphases are put on the study of some threshold-based segment techniques and Canny operator segment method. The thesis selects Canny operator to segment the image because Canny operator can provide the gradient orientation angle and it can segment the image efficiently. Camera calibration technique is an indispensable part of the vision system. In the thesis, many efforts are made on the study of the linear camera calibration technique, which is based on pin-hole imaging model and at last a simple and feasible camera calibration technique is determined according to the experience. Characteristic curve extraction technique is also an important technique. The techniques of ellipse and line extraction, including the dominant point detection are studied in the thesis on the basis of thecharacteristics of the traffic sign. Three-dimension recovery is the most important technique expounded and also serves as the most innovational point in the thesis. Through research, we put forward the techniques of the circle and triangle object recovery and make them as the modules so that they can be easily transplanted. Image matching is a recognition process after the object is three-dimension recovered. In the thesis, we spare no effort to introduce the image matching theory and some matching methods. In light of the optic character recognition principle and after the dominant feature matching, the images are matched to the module images.The image being static, the technique of the system isn't real-time. But considering the present study situation in china, the theory study in the thesis makes for the advance of the traffic sign recognition. Therefore the thesis has its practical significance.