关键词: 车牌提取, 车牌校正, 车牌分割, 车牌识别, 神经网络, 智能交通

Abstract: For the defects of the key technology of the existing license plate recognition system，the key technologies of the system are improved.The techniques of license plate location and extraction adopt the method combining the image 2D energy and the HIS color space.Besides，the existing method of energy and image segmentation is improved.For the tilt correction technology，a new method based on the gravity of the density of the binary image is presented，in the recognition technology，a new method is introduced combining the feature extraction and multiply BP neural network learning.Considering the similarity of the characters in the license plate，a two-step neural network is proposed to recognize the characters.Experimental results show that the system with the key technology of the license plate recognition system is more of robustness and more of precision.

Key words: license plate extraction, license plate correction, license plate segmentation, license plate recognition, neural network, intelligent transportation system