Vehicle Speed Measurement by Locating the License Plates

• Main Authors: Kun-Wei Lin, 林昆緯
• Other Authors: 丁肇隆
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/77024701562710376816

碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 99 === Recently, as the development of digital image processing of plate-locating and speed-detecting, the application of plate-locating and speed-detecting for vehicle con- trol expands from streets to toll stations and parking lots. Our research proposes detecting the speed of vehicles by located plates which is faster than traditional detecting ways. In this way, there is no need to locate the plates for the speeding vehicles. The located plates will be saved in database regardless of the speeds of the vehicles which could supervise vehicles more effectively. The speed calculation method we propose reduces the camera parameters which need to be calibrated. There are mainly two speed-detecting methods. One way is to use two calibration lines within the images. Considering of the perspective of the images, the other is to use the information of the vehicle which is projected on the ground. However, in our research, the objects in the images which are going to be esti- mated the distance to the camera don’t have to be projected on the ground. In addition, we distinguish colors of vehicles into light color and dark color to process vehicle detecting, plate detecting, plate tracking and speed estimation in all day automatically. The correc- tion rate of overall system is 95% and the estimated error of the vehicle speed is under 2 km/h.