# How to center the caption in onecolumn space?

I used the commands \onecolumn and \twocolumn to have some images in one column, but now the images' captions are not centered. How can I solve this problem?

My code is like below:

\one column

\begin{figure}[p]

\centering

....

\caption{...}

\label{fig:...}

\end{figure}

\twocolumn


\documentclass[journal]{IEEEtran}
\usepackage{times,amsmath,epsfig,amssymb,graphicx,amsfonts,pxfonts,txfonts,float‌​}
\usepackage{subfigure,ifpdf,cite}
\begin{document}
\begin{figure*}[p]
\centering \subfigure[]
{\label{fig:Original}
\includegraphics[width=70mm]{Lena.pdf}}%
\label{fig:image}
\end{figure*}
\nocite{*}
\bibliographystyle{IEEEtran}
\bibliography{meee}
\end{document}

-
To put an image in one column format while rest of the document is in two column, you can use the environment figure*. –  Harish Kumar May 23 '12 at 15:59
I don't know how to use the environment you said. I actually used the figure environment(\begin{figure}). –  Mohammad May 23 '12 at 16:09
In a two column document, simply use \begin{figure*}....\end{figure*}. –  Harish Kumar May 23 '12 at 16:11
Thank you, I write as you said, but my problem is not solved yet. I mean the caption is not centered yet! –  Mohammad May 23 '12 at 16:16
@Mohammad: Is the caption longer than the width of the text block? By default, LaTeX will centre the caption only if its less than the width of the text block, and set it in paragraph mode/style otherwise. This can be changed though. –  Werner May 23 '12 at 16:30

If you are preparing a paper for a journal and the journal requests you to use the IEEEtran class with the journal class option, then captions for figures won't be centered by design, and I suggest you to leave them as they are. If you're not forced to use the journal option for IEEEtran, then simply load the class with the conference option (by deafult, one-line figure captions will now be centered):
\documentclass[conference]{IEEEtran}