tikz-with-image

tikz-with-overlay.tex

\begin{frame}[m]\frametitle{}
\begin{tikzpicture}
\node[] (image) at (0,0) {\includegraphics[scale=.27]{btard_ae}\includegraphics[scale=.27]{btemp_ae}\includegraphics[scale=.27]{mono_ae}};
\end{tikzpicture}
\end{frame}

\begin{frame}[m]\frametitle{}
\begin{tikzpicture}
\node[] (image) at (0,0) {\includegraphics[scale=.27]{btard_ae}\includegraphics[scale=.27]{btemp_ae}\includegraphics[scale=.27]{mono_ae}};
\draw [-latex] (-5.35,.5) to[bend right=15] (-4.45,-0.15);
\node[fill=black, opacity=.5, text opacity=1] at (-5,1) {\normalsize \color{red} Significant};
\draw[red,ultra thick,rounded corners] (-1,-1) rectangle (.75,.65);
\end{tikzpicture}
\end{frame}