Character String Envelope Correlation based Vehicle License Plate Tilt Correction in Vertical Direction
Obtaining vehicle license plate (VLP) character strings from VLP image is an essential technology in the intelligent transportation systems.The accuracy of character string segmentation would be greatly impacted by character string tilt resulted from different imaging angle.A character string envelope based vertical tilt correction method is proposed in this paper according to VLPs symmetry characteristic of character string and character space.Firstly,top envelope and foot envelope are calculated from VLP character string.Then,based on the cross-correlation function of top envelope and foot envelope,the coordinate of maximum value of the cross-correlation function which is corresponding to the horizontal axis offset is obtained to calculate the VLPs incline angle in vertical direction.The experimental results show that the proposed method performs better in both time complexity and evaluation error of the vertical tilt angle compared with other methods.
Vertical tilt correction top and foot envelopes cross-correlation function shear transformation
Fu Zhizhong Zhao Yu Li Xiaofeng Guo Wenbo
University of Electronic Science and Technology of China Chengdu,China
国际会议
重庆
英文
160-164
2016-03-20（万方平台首次上网日期，不代表论文的发表时间）