# Optical Flow Odometry with Panoramic Image Based on Spherical Congruence Projection
## 4 Experiments and Discussion
### Optical Flow Continuity Examination  
As discussed in Section 3.2, the QUVS image is segmented into six subimages. During the optical flow tracking, feature points may transition from one subregion to another. Figure 13 illustrates the cross-domain movement of optical flow between these subregions. The results indicate that the feature points near boundaries can be accurately transferred to adjacent subimages, with the optical flow direction aligning with the overall movement. This consistency suggests that the proposed cross-domain optical flow tracking strategy effectively identifies the predicted coordinates of tracked feature points within neighboring subimages.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Operator Type** & **Index** & & **ID01** & **ID02** & **ID04** & **RS01** & **RS02** & **RS03** & **RS04** \\ \hline \multirow{3}{*}{\begin{tabular}{c} LK \\ operator \\ \end{tabular} } & RPEt (\%) & \begin{tabular}{c} RMSE \\ std \\ \end{tabular} & 1.733 & 1.548 & **0.976** & 1.894 & 1.844 & 2.302 & 2.615 \\  & RPEt (deg/m) & \begin{tabular}{c} RMSE \\ std \\ \end{tabular} & **0.891** & 1.039 & 0.543 & 1.243 & **1.236** & 1.548 & 1.759 \\  & RPEt (deg/m) & \begin{tabular}{c} RMSE \\ std \\ \end{tabular} & 1.275 & **0.566** & 0.479 & 2.416 & 2.649 & 2.813 & 2.633 \\  & std & 0.825 & 0.473 & 0.350 & 2.074 & **2.269** & 2.363 & **1.932** \\ \hline \multirow{3}{*}{\begin{tabular}{c} SCP \\ operator \\ \end{tabular} } & RPEt (\%) & \begin{tabular}{c} RMSE \\ std \\ \end{tabular} & **1.703** & **1.348** & 0.997 & **1.863** & **1.831** & **2.041** & **2.344** \\  & RPEt (deg/m) & \
\begin{tabular}{c} std \\ std \\ \end{tabular} & 0.900 & **0.819** & **0.533** & **1.240** & 1.299 & **1.267** & **1.473** \\  & RPEt (deg/m) &
\begin{tabular}{c} RMSE \\ std \\ \end{tabular} & **1.026** & 0.569 & **0.478** & **2.292** & **2.648** & **2.245** & **2.578** \\  & std & **0.559** & **0.406** & **0.354** & **1.938** & 2.271 & **1.776** & 2.122 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Experimental results for LK gradient operator and SCP gradient operator.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Index** & **a** & **b** & \begin{tabular}{c} **RPEt (\%)** \\ **RMSE** \\ \end{tabular} & \begin{tabular}{c} **RPEr (deg/m)** \\ **RMSE** \\ \end{tabular} & \begin{tabular}{c} **ATE (m)** \\ **RMSE** \\ \end{tabular} & \
\begin{tabular}{c} **ATE (m)** \\ **RMSE** \\ \end{tabular} &
\begin{tabular}{c} **STd** \\ \end{tabular} \\ \hline
1 & 2 & 4 & 3.514 & 2.174 & 9.901 & 9.796 & 1.357 & 0.554 \\
2 & 3 & 6 & 3.297 & 2.117 & 9.954 & 9.850 & 1.142 & 0.444 \\
3 & 4 & 8 & 3.786 & 2.702 & 9.541 & **9.442** & 1.128 & 0.461 \\
4 & 5 & 10 & 3.085 & **2.021** & **9.935** & 9.835 & **0.983** & **0.376** \\
5 & 6 & 12 & **3.084** & 2.096 & 9.943 & 9.841 & 1.028 & 0.438 \\
6 & 7 & 14 & 4.338 & 3.119 & 9.952 & 9.840 & 1.059 & 0.395 \\
7 & 8 & 16 & 3.563 & 2.736 & 9.968 & 9.856 & 1.124 & 0.440 \\
8 & 9 & 18 & 3.502 & 2.307 & 9.936 & 9.838 & 1.232 & 0.505 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Experimental results for ablation on SCP gradient operator weighting in SCP-VIO.