Algorithm 1 Rules of paired marking points confirmation

Input:   Two sets $\mathbb{B}$ and $\mathbb{P}$, comprising all bounding boxes and marking points in an around view image, respectively. Output:  Paired marking points. 1: for$\mathbf{B}$ in $\mathbb{B}$ do 2:   for $\mathbf{p}$ in $\mathbb{P}$ do 3:     Count the number N of $\mathbf{p}$ in $\mathbf{B}$ 4:   end for 5:   if N = 2 then 6:     ${\mathbf{p}}_1$ and ${\mathbf{p}}_2$ are paired marking points 7:   end if 8:   if N = 1 and the confidence of $\mathbf{B}$ > 95% then 9:     Step 1: Calculate the other marking point ${{\mathbf{p}}_2}^{\prime }$ using Equation (4) 10:     Step 2: ${\mathbf{p}}_1$ and ${{\mathbf{p}}_2}^{\prime }$ are paired marking points 11:   end if 12:   if N = 0 and the confidence of $\mathbf{B}$ > 98% then 13:     Step 1: Calculate the NAIV of the four vertex regions of $\mathbb{B}$ using Equation (5) 14:     Step 2: The largest NAIV set of diagonal vertices ${{\mathbf{p}}_1}^{\prime }$ and ${{\mathbf{p}}_2}^{\prime }$ are paired marking points 15:   end if 16:   if N > 2 then 17:     Two points ${\mathbf{p}}_1$ and ${\mathbf{p}}_2$ that is the closest to the diagonal vertices of $\mathbf{B}$ are paired marking points 18:   end if 19:  end for