Q:

Graphics not centering properly

I am inserting an image into my document using
\begin{figure}[!htbp]
\centering
\includegraphics[width=0.7\textwidth,natwidth=338,natheight=176]{images/cloud_stack.png}
\caption{Service model stack}
\label{fig:cloud_stack}
\end{figure}

The image ends up being slightly off-center to the left (the caption is centered correctly). 

This is happening for all of the images in the document. Tables are centered correctly. I'm using TeXstudio's DVI->PDF chain with MiKTeX 2.9 on Windows.
Edit:
Using \fbox{\includegraphics{..}} shows extra whitespace inside the box:

A:

The default units for natheight and natwidth keys are bp (so that it matches the units of an EPS BoundingBox comment). Using \fbox you can see the actual size of the image is much smaller but classic TeX can not see that and uses whatever size you give.
If instead you used pdflatex then you could omit the natheight and natwidth keys and let the system measure the image exactly as it includes it.

