-\section{ifexport}\label{ifexport}\index{ctsimtext,ifexport}%
-Export an imagefile to a standard graphics file.
-
-\usage
-\begin{itemize}\itemsep=0pt
- \item --format
- \begin{itemize}\itemsep=0pt
- \item --pgm
- \item --pgmasc
- \item --png
- \item --png16
- \end{itemize}
- \item --center
- \begin{itemize}\itemsep=0pt
- \item median
- \item mode
- \item mean
- \end{itemize}
- \item --auto
- \begin{itemize}\itemsep=0pt
- \item --full
- \item --std0.1
- \item --std0.5
- \item --std1
- \item --std2
- \item --std3
- \end{itemize}
- \item --scale
- \item --min
- \item --max
-\end{itemize}
-
-\section{ifinfo}\label{ifinfo}\index{ctsimtext,ifinfo}%
-
-Displays information about an imagefile.
-
-\usage
-\begin{itemize}\itemsep=0pt
- \item --labels
- \item --no-labels
- \item --stats
- \item --no-stats
- \item --help
-\end{itemize}
-
-\section{phm2pj}\label{phm2pj}\index{ctsimtext,phm2pj}%
-Simulates collection of X-rays data (projections) around a phantom object.
-
-\usage
-phm2pj projection-file-name number-of-detectors number-of-views [options...]
-\begin{itemize}\itemsep=0pt
- \item --phantom
- Select a standard phantom
- \begin{itemize}\itemsep=0pt
- \item herman
- \item herman-b
- \item shepp-logan
- \item shepp-logan-b
- \end{itemize}
-
- \item --phmfile
- Load a phantom definition definition
-
- \item --geometry
- \begin{itemize}\itemsep=0pt
- \item parallel
- \item equiangular
- \item equilinear
- \end{itemize}
-
- \item --nray
- Number of samples per each detector
-
- \item --rotangle
- Sets the rotation amount as a multiple of pi. For parallel geometries use
-a rotation angle of 1 and for equilinear and equiangular geometries use a rotation angle of 2.
-
- \item --field-of-view
- Sets the field of view as a ratio of the diameter of the phantom. For parallel geometries, using a value of 1.0 is fine. For other geometies, this should be at least 1.3 to avoid artifacts.
-
- \item --focal-length
- Sets the distance of the radiation source and detectors from the center of the object as a ratio of the radius of the object. For parallel geometries, a value of 1.0 is fine. For other geometries, this should be at least 2.0 to avoid artifacts.
-\end{itemize}
-
-The Herman phantom is taken with permission from Gabor Hermans 1980 book\cite{HERMAN80}. The Shepp-Logan phantom was published in 1974\cite{SHEPP74}.
-
-\section{phm2if}\label{phm2if}\index{ctsimtext,phm2if}%
-Converts a geometric phantom object into an imagefile. The size of the
-imagefile in pixels must be specified as well as the number of samples
-to average per pixel.
-
-\usage
-\begin{itemize}\itemsep=0pt
- \item --nsamples
-\end{itemize}
-
-\section{pj2if}\label{pj2if}\index{ctsimtext,pj2if}%
-Convert a projection file into an imagefile.
-
-\usage
-\begin{itemize}\itemsep=0pt
-\end{itemize}
-
-\section{pjinfo}\label{pjinfo}\index{ctsimtext,pjinfo}%
-Displays information about a projection file.
-
-\usage
-\begin{itemize}\itemsep=0pt
- \item --binaryheader
- \item --binaryview
- \item --startview
- \item --endview
- \item --dump
-\end{itemize}
-
-\section{pjrec}\label{pjrec}\index{ctsimtext,pjrec}%
-Reconstructs the interior of an object from a projection file.
-
-\usage
-\begin{twocollist}
-\twocolitemruled{{\bf Parameter}}{{\bf Options}}
-\twocolitem{{\bf --filter}}{Selects which filter to apply to each projection. To properly reconstruct an image, this filter should be multiplied
-by the absolute value of distance from zero frequency.
- \begin{itemize}\itemsep=0pt
- \item abs_bandlimit
- \item abs_cosine
- \item abs_hamming
- \end{itemize}}
- \twocolitem{{\bf --filter-parameter}}{Sets the alpha level for Hamming
- window. At setting of 0.54, this equals the Hanning window.}
- \twocolitem{{\bf --filter-method}}{Selects the filtering method. For large numbers of detectors, {\tt rfftw} is optimal. For smaller numbers of detectors, {\tt convolution} might be a bit faster.
-\begin{itemize}\itemsep=0pt
-\item convolution
- \item fourier
- \item fourier_table
- \item fftw
- \item rfftw
-\end{itemize}}
- \twocolitem{{\bf --filter-generation}}{Selects the filter generation. With convolution, {\tt direct} is the proper method to select. With any of the frequency methods, {\tt inverse-fourier} is the best method.
-\begin{itemize}\itemsep=0pt
-\item direct
- \item inverse-fourier
-\end{itemize}
-}
- \twocolitem{{\bf --interpolation}}{Interpolation technique. {\tt linear} is optimal.
-\begin{itemize}\itemsep=0pt
-\item nearest
-\item linear
-\end{itemize}
-}
- \twocolitem{{\bf -backprojection}}{Selects the backprojection technique. A setting of {\tt idiff3} is optimal.
-\begin{itemize}\itemsep=0pt
-\item trig
-\item table
-\item diff
-\item diff2
-\item idiff2
-\item idiff3
-\end{itemize}
-}
-\twocolitem{{\bf --zeropad}}{ Zeropad factor. A setting of {\tt 1} is optimal.}
-
- \twocolitem{{\bf --preinterpolate}}{Selects preinterpolation interpolation technique and sets the preinterpolation factor. Currently, this is experimental and does not work well.}
-\end{twocollist}
-
-\chapter{The Web Browser CGI Interface}\label{webinterface}\index{Web Interface}%
-\setheader{{\it CHAPTER \thechapter}}{}{}{}{}{{\it CHAPTER \thechapter}}%
-\setfooter{\thepage}{}{}{}{}{\thepage}%
-
-\section{Overview}\index{Web Interface,Overview}%
-The CGI program {\tt 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 standard
-statistics as described by Herman\cite{HERMAN80}.
-
-\section{Requirements}\index{Web Interface,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.
- \end{itemize}