The results are shown in Figure 4(a) and Figure 4(b). Now, sampling values from grey scale signal likes Figure 4(b) in every five pixels and declare values of high frequency part and continuous low frequency part as zero. The results are shown in Figure 5(a). After that, extract the continuous signal’s part and shown in Figure 5(b). If no vehicle detected by scan line, the value of final grey scale signal will be all equal to zero.