If you want to include an image in your chapter title, what follows may be an option:
\newcommand{\thechapterimage}{}
\newcommand{\chapterimage}[1]{\renewcommand{\thechapterimage}{#1}}
\def\thechapter{\Roman{chapter}}
\def\@makechapterhead#1{%
{\centering \normalfont\sffamily
\ifnum \c@secnumdepth >\m@ne
\if@mainmatter
\vspace*{-3.9cm}\hspace*{-3.1cm}% to position the figure
\includegraphics[width=\paperwidth]{\thechapterimage}\par
\rput[lb](0,2){\sffamily\bfseries\thechapter}}\par
\vspace*{30\p@}%
}
Then, in the main document, you would call the name of a figure just before the chapter command:
\chapterimage{image.eps}
\chapter{Title}
What is the exact role of the first two commands \thechapterimage
and \chapterimage
above?