multiple figures, subfigure

\begin{figure}[htp]
  \begin{center}
    \subfigure[Original image]{\label{fig:edge-a}\includegraphics[scale=0.75]{toucan.eps}}
    \subfigure[After Laplace edge detection]{\label{fig:edge-b}\includegraphics[scale=0.75]{laplace_toucan.eps}} \\
    \subfigure[After Sobel edge detection]{\label{fig:edge-c}\includegraphics[scale=0.75]{sobel_toucan.eps}}
  \end{center}
  \caption{Various edge detection algorithms}
  \label{fig:edge}
\end{figure}