2.3.2 Locate the upper and lower horizontal referent point After detection the tick marks’ location, the distance from top-left to top-right tick marks is divided uniformly into 8 points. (see Figure 5) and name it U1, U2, U3, … U8.
2.3.2 Locate the upper and lower horizontal referentpoint After detection the tick marks’ location, the distance fromtop-left to top-right tick marks is divided uniformly into 8 points.(see Figure 5) and name it U1, U2, U3, … U8.