我有这个数字表：
\begin{figure}[th!]
\setlength\tabcolsep{1pt}
\settowidth\rotheadsize{Radcliffe Cam}
\begin{tabularx}{\linewidth}{l XXXX }
&Original & WI & \multicolumn{2}{c}{TPWI} \\ \addlinespace[2pt]
\rothead{Rogue One: A Star Wars Story} &
\includegraphics[width=\hsize,valign=m]{Figures/original_rogue_one.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_4678.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_4669.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_20170120_115803.jpg}\\ \addlinespace[2pt]
\rothead{Split} & \includegraphics[width=\hsize,valign=m]{Figures/original_split.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_20170120_111446.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_5090.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_4738.jpg}\\ \addlinespace[2pt]
\rothead{Bacchus} & \includegraphics[width=\hsize,valign=m]{Figures/original_bacco-caravaggio.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_9965.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_20170112_164436.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_20170524_175644.jpg}\\ \addlinespace[2pt]
\rothead{The Birth of Venus} & \includegraphics[width=\hsize,valign=m]{Figures/original_nascita_di_venere-sandro_botticelli.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_20170112_111245.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_8864.jpg}
& \includegraphics[width=\hsize,valign=m]{Figures/IMG_20170524_131835.jpg}\\ \addlinespace[2pt]
\end{tabularx}
\caption{Instances from the movie and poster dataset. The leftmost column are the original instances. The second column are good quality WI. The two right most columns are TPWI images.}
\label{fig:samples}
\end{figure}
在 2 列文档中其样子如下：
如您所见，最后一行有一个很大的空白。同样，另一个遵循上述相同格式的表格中也出现了这种情况。我该如何删除它以节省空间？