\chapter{The Web Interface}\label{webinterface}\index{Web Interface}%
\setheader{{\it CHAPTER \thechapter}}{}{}{\ctsimheadtitle}{}{{\it CHAPTER \thechapter}}%
\ctsimfooter%

\section{Overview}
\ctsim\ can also be executed via a web browser. The CGI program
\texttt{ctsim.cgi} takes projections of a standard phantom object,
performs reconstruction, and then compares the rasterized phantom
object with the reconstruction. The comparison is performed both
visually by an image subtraction as well as by statistical
analysis.

\section{Requirements}
   \begin{itemize}\itemsep=0pt
      \item Apache or other CGI compatible web server

      \item Perl (version 4.0 or higher)

      \item A client web browser than can display PNG files. Most
      current web browsers support PNG.

      \item A knowledgable system administrator. It is beyond the
      scope of this manual to explain the configuration a web server.
  \end{itemize}
