Algorithm for Car License Plate Location Based on Fractal Dimension of Waveforms
ZHUGE Bin1, 2, ZHOU HeQin2
1.College of Information and Electronic Engineering, Zhejiang Gongshang University, Hangzhou 310035 2.Department of Automation, University of Science and Technology of China, Hefei 230027
Abstract：According to the distribution of the characters on a car license plate (CLP), a new location method based on distribution of fractal dimension of waveforms (FDW) is proposed in this paper. Using the method of sliding windows, the FDW for each line gray curve of every photo is estimated and two dimension distribution of FDW are gotten. Through processing the distribution of FDW, the CLP zone can be segmented easily. The experimental results show that FDW is effective for the attribute of the characters alignment on CLP and it is not affected by the background, the color and the type of CLP. Besides, the proposed algorithm is not sensitive to the sloping license plate and the accuracy rate of location for 1000 complicated background photos reaches 98. 9%.
[1] Chang S L, Chen L S, Chung Y C, et al. Automatic License Plate Recognition. IEEE Trans on Intelligent Transportation Systems, 2004, 5(1): 42-53 [2] Zhang Yin, Pan Yunhe. A New Approach for Vehicle License Plate Locating from Color Image. Journal of Image and Graphics, 2001, 6(4): 374-377 (in Chinese) (张 引,潘云鹤. 彩色汽车图像牌照定位新方法.中国图象图形学报, 2001, 6(4) : 374-377) [3] Xiong Jun, Gao Duntang, Shen Qinhong, et al. A Fast Locating Algorithm Based on Character Texture Characteristics. Opto-Electronic Engineering, 2003, 30(2): 60-63 (in Chinese) (熊 军,高敦堂,沈庆宏,等. 基于字符纹理特征的快速定位算法.光电工程, 2003, 30(2): 60-63) [4] Guo Jie, Shi Pengfei. Color and Texture Analysis Based Vehicle License Plate Location. Journal of Image and Graphics, 2002, 7(5): 472-476 (in Chinese) (郭 捷,施鹏飞. 基于颜色和纹理分析的车牌定位方法. 中国图象图形学报, 2002, 7(5): 472-476) [5] Cao Gang, You Zhisheng, Zhao Shulong. A Method of Fast Vehicle-License-Plate Location Based on Adaptive Energy Filter. Journal of Optoelectronics·Laser, 2003, 14(5): 523-525,528 (in Chinese) (曹 刚,游志胜,赵树龙. 一种基于自适应能量滤波的快速车牌定位方法. 光电子·激光, 2003, 14(5): 523-525,528) [6] Jin Yisu, Yuan Baoming, Yu Wanbo, et al. A Location Method of Vehicle-License-Plate Based on Fractal Box Dimension. Application Research of Computers, 2002, 19(9): 40-41,44 (in Chinese) (金一粟,袁宝民,于万波,等. 基于分形盒子维数的车牌定位方法. 计算机应用研究, 2002, 19(9): 40-41,44) [7] Esteller R, Vachtsevanos G, Echauz J, et al. A Comparison of Fractal Dimension Algorithms Using Synthetic and Experimental Data // Proc of the IEEE International Symposium on Circuits and Systems. Orlando, USA, 1999, Ⅲ: 199-202 [8] Petrosian A. Kolmogorov Complexity of Finite Sequences and Recognition of Different Preictal EEG Patterns // Proc of the 8th IEEE Symposium on Computer-Based Medical Systems. Lubbock, USA, 1995: 212-217 [9] Katz M J. Fractals and the Analysis of Waveforms. Computers in Biology Medicine, 1988, 18(3): 145-156 [10] Sevcik C. A Procedure to Estimate the Fractal Dimension of Waveforms. Complexity International, 1998, 5: 17-21
2006, Vol. 19 
