\documentclass{scrartcl}
%% print cd covers!!
%% Adapt the file names Front.jpg and Back.jpg to your needs
%% Run this file through pdflatex
\usepackage{graphicx}
\usepackage{typearea}
\usepackage{printlen}
\pagestyle{empty}
\uselengthunit{mm} %\printlength{\textwidth}
\areaset{18cm}{27cm} % Take care, when printing with acrobat: don't resize the pages
\begin{document}
\vspace*{1cm}
\newsavebox{\mybox}
\sbox{\mybox}{\includegraphics[width=12.2cm]{Front.jpg}}
\usebox{\mybox}

%Picture size: (\printlength{\wd\mybox} / \printlength{\ht\mybox})

\vspace{1cm}

\sbox{\mybox}{\includegraphics[width=15.1cm]{Back.jpg}}
\usebox{\mybox}

%Picture size: (\printlength{\wd\mybox} / \printlength{\ht\mybox})
\end{document}

%%% Local Variables:
%%% mode: latex
%%% TeX-master: t
%%% End:

%%% arch-tag: 59538d7d-3dcf-4a90-9e3b-b3eb9d726bca