\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{rsfs}

\usepackage{graphicx}
\usepackage{color}

\textheight 260mm
\topmargin 5mm
\textwidth 180mm
\oddsidemargin -7mm


\begin{document}

\begin{figure}[bhtp]
\begin{center}
%% \includegraphics[width=18cm,height=8cm]{iter_1.bmp}
%% \includegraphics[width=18cm,height=8cm]{iter_1.gif}
\includegraphics[width=18cm, height=8cm]{iter_1.jpg}
\end{center}
\end{figure}

\end{document}


