# prevent page break while returning to twocolumn

I'm writing a IEEE conference paper. The format of paper is \documentclass[conference]{IEEEtran} For inserting a wide image i switched to one column using \onecolumn The image took half of my page. After that when I again issued command \twocolumn it resulted in page break and the two column contents thereafter are appearing from next page. Can anyone please help me as to what I can do to prevent the page break.

You can put a wide image that spans both columns at the top of the page, either by using a two column float (figure*) or by using the optional argument of \twocolumn which specifies a spanning text to be put over the columns, so

\documentclass[conference]{IEEEtran}
\usepackage{graphicx}
\begin{document}

\twocolumn[%
{\includegraphics[width=\textwidth]{example-image}}%
]

\loop
\stepcounter{enumi}
\ifnum\value{enumi}<1000
\roman{enumi}
\repeat

\end{document}