wmsys.tex

\documentclass{article}
\usepackage{epsfig}
\usepackage{pstricks}

\pagestyle{empty}
\begin{document}
%\color{white}% fbox invisible
\fboxsep=0pt
%\fbox{%
  \begin{pspicture}(0,0)(12,4.5)
    \psframe[linestyle=dashed](0,1.5)(2,3) 
      \psframe[linestyle=solid](2,1.5)(4,3) \rput(3,2.25){Embedding}
      \psline[arrowsize=2pt 4,arrowlength=2,arrowinset=0]{->}(3,4)(3,3) \rput(3.9,3.6){Stego-key $k$}
      \psline[arrowsize=2pt 4,arrowlength=2,arrowinset=0]{->}(1,2.25)(2,2.25) \rput(1,2.5){Cover-} \rput(1,2){data $\mathbf{c}$}
      \psline[arrowsize=2pt 4,arrowlength=2,arrowinset=0]{->}(3,0.5)(3,1.5) \rput(3.8,1){Embedded} \rput(3.8,0.7){data $m$}

      \psline[arrowsize=2pt 4,arrowlength=2,arrowinset=0]{->}(4,2.25)(7,2.25)
      \rput(5.5,2.5){Stego-data $\mathbf{s}$}

      \psframe[linestyle=solid](7,1.5)(9,3) \rput(8,2.25){Extracting}
      \psframe[linestyle=dashed](9,1.5)(11,3) 
      \psline[arrowsize=2pt 4,arrowlength=2,arrowinset=0]{->}(8,4)(8,3) \rput(8.9,3.6){Stego-key $k$}
      \psline[arrowsize=2pt 4,arrowlength=2,arrowinset=0]{->}(9,2.25)(9.6,2.25)
      \rput(10.2,2.5){Restored} \rput(10.2,2){cover $\mathbf{c}'$}
      \psline[arrowsize=2pt 4,arrowlength=2,arrowinset=0]{<-}(8,0.5)(8,1.5) \rput(8.8,1){Embedded} \rput(8.8,0.7){data $m$}

  \end{pspicture}
%}
\end{document}