\begin{figure} \centering \begin{subfigure}{0.35\linewidth} \includegraphics[width=\textwidth]{figure/image1.png} \caption{Training with raw data} \end{subfigure} \hspace{4mm} \begin{subfigure}{0.58\linewidth} \includegraphics[width=\textwidth]{figure/image2.png} \caption{Training with synthetic data} \end{subfigure} \caption{Risk propagation of training a learning model with synthetic data instead of raw data.} \end{figure}