\setbeamertemplate{footline}{} 
\begin{frame}[plain]
    % Print the title page as the first slide
    \titlepage
%\hfill\includegraphics[width=2cm]{./img/Mines.jpg}
%{\includegraphics{./img/Mines_background12.pdf}}
\setbeamertemplate{background} 
{
{\includegraphics[width=\paperwidth,height=\paperheight,keepaspectratio]{./img/Mines_background12.pdf}}
}

\end{frame}