\documentclass{article}
\usepackage[french,english]{babel}
 \usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}

\usepackage{comment}
\specialcomment{French}{\begingroup\selectlanguage{french}\tt}{\endgroup}
\begin{document}
This is english.
\begin{French}
C'est du français.
\end{French}
\begin{toimage}
\begin{French}
Fran\c{c}ais en image.
\end{French}
\end{toimage}
\imageflush
\end{document}
