% -*- coding : utf8 -*-
\documentclass{beamer}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[french]{babel}
\usepackage{lmodern}

\usepackage{graphicx}

%%%%
%  For externalimage :
% specials.sty and supp-mpe_mod.tex 
% must be in the path
\usepackage{specials}
\LoadMetaPostSpecialExtensions
%%%%

%%%%
% For \includesomegraphics< > :
% beamer_mlpost.sty must be in the path
\usepackage{beamer_mlpost}
%%%%

\begin{document}

\begin{frame}
  \includesomegraphics<1-4>[width=3cm]{image}
\end{frame}

\begin{frame}
  \includesomegraphics<1-4>{image}
\end{frame}

\begin{frame}
  \includesomegraphics<1-4>[width=3cm]{image_ro}
\end{frame}

\begin{frame}
  \includesomegraphics<1-4>{image_ro}
\end{frame}

\end{document}
