begin{figure}[bbp]
centering
includegraphics[resolution=72, width=40mm]{bilder/rmv_tag.png}
caption[RMV-Kontaktpunkt am Bahnhof]{RMV-Kontaktpunkt am Bahnhof, Quelle:
http://goo.gl/i1k0l}
label{pic:rmv}
end{figure}

includegraphics[bb=0 0 urx ury, width=40mm]{yourGraphicsFile.png}