% file `eso-ex2.tex'; an example for background pictures

\documentclass{article}

\usepackage{eso-pic}
\usepackage{graphicx}

% `rose.eps' from CTAN: macros/generic/boxedeps/
\newcommand\BackgroundPicture{%
  \put(0,0){%
   \parbox[b][\paperheight]{\paperwidth}{%
     \vfill
     \centering
     \includegraphics[width=\paperwidth,height=\paperheight,%
                      keepaspectratio]{rose}%
     \vfill
    }
  }
}
% The picture is centered on the page background

\AddToShipoutPictureBG{\BackgroundPicture}

\begin{document}

\section{\TeX}

\newpage

\ClearShipoutPicture
\section{Empty}

\newpage

\AddToShipoutPictureBG{\BackgroundPicture}
\section{\LaTeX}

\end{document}