\begin{table}[!htb]
\centering
\caption{Average comparative metrics using an image domain U-Net architecture as a reconstruction network.}
\resizebox{0.9\textwidth}{!}{%
\begin{tabular}{clccclccclccc}
\hline
\multirow{2}{*}{\textbf{Setup}} &  & \multicolumn{3}{c}{\textbf{4x}}                 &           & \multicolumn{3}{c}{\textbf{8x}}                 &           & \multicolumn{3}{c}{\textbf{16x}}                \\ \cline{3-5} \cline{7-9} \cline{11-13} 
                                &  & SSIM           & pSNR          & NMSE           &           & SSIM           & pSNR          & NMSE           &           & SSIM           & pSNR          & NMSE           \\ \cline{1-1} \cline{3-5} \cline{7-9} \cline{11-13} 
SSL                             &  & 0.854          & 33.0          & 0.013          &           & 0.742          & 29.4          & 0.030          &           & 0.651          & \textbf{26.7} & \textbf{0.055} \\
JSSL                            &  & \textbf{0.863} & \textbf{33.5} & \textbf{0.012} & \textbf{} & \textbf{0.759} & \textbf{29.7} & \textbf{0.027} & \textbf{} & \textbf{0.663} & 26.7          & 0.055          \\ \hline
\end{tabular}%
}
\label{tab:metrics_unet}
\end{table}