I use the following code:
\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{center}
\includegraphics{GR0568 q28.png}
\end{center}
\end{document}
and get this output:

Why does it publish "q28.png"? I'm sure I could fix this if I didn't have a space in the filename, but is there another workaround?
\inputfilenames are not automatically quoted for spaces but if you must you can (with web2c based tex implementations) use"file foo .png"– David Carlisle Sep 29 '14 at 00:06