\documentclass{book}

\usepackage{graphicx,geometry}

\graphicspath{{media/}}

\begin{document}
    \begin{titlepage}
        \begin{centering}
            \newgeometry{margin=0cm}
                \includegraphics[height=\paperheight]{cover.png}
            \restoregeometry{}
        \end{centering}
    \end{titlepage}
\end{document}