\documentclass[a4paper]{article}

%% Language and font encodings
\usepackage[english]{babel}
\usepackage[utf8x]{inputenc}
\usepackage{graphicx}


\usepackage[a4paper,top=3cm,bottom=2cm,left=3cm,right=3cm,marginparwidth=1.75cm]{geometry}

\begin{document}
	\noindent
	\newgeometry{top=0cm, bottom=0cm, left=-0.5625cm, right=0cm}
	\parbox{\paperwidth}{\includegraphics[width=\paperwidth,height=\paperheight]{cover.png}}
	\restoregeometry

\end{document}