1 \chapter{ctsimtext}\label{ctsimtext}\index{ctsimtext}%
2 \setheader{{\it CHAPTER \thechapter}}{}{}{}{}{{\it CHAPTER \thechapter}}%
3 \setfooter{\thepage}{}{}{}{}{\thepage}%
5 \ctsimtext\ is a master shell for all of the command-line utilities.
8 \ctsimtext\ can be executed without any parameters. In that case, \ctsimtext\
9 offers a command-line to enter the function-names and their parameters. The output of the command is displayed. Further commands may be given to \ctsimtext. The shell is exited by the {\tt quit} command.
11 \ctsimtext\ can also be called to execute a single command. This is especially useful for batch files containing multiple \ctsimtext\ commands. This is invoked by calling \par
12 {\tt ctsimtext function-name parameters...}.
14 The available functions are:
16 \section{if1}\label{if1}\index{ctsimtext,if1}%
17 Perfoms math functions on a single image.
20 \begin{itemize}\itemsep=0pt
28 \section{if2}\label{if2}\index{ctsimtext,if2}%
29 Perfoms math functions on a two images.
32 \begin{itemize}\itemsep=0pt
41 \section{ifexport}\label{ifexport}\index{ctsimtext,ifexport}%
42 Export an imagefile to a standard graphics file.
45 \begin{itemize}\itemsep=0pt
47 \begin{itemize}\itemsep=0pt
54 \begin{itemize}\itemsep=0pt
60 \begin{itemize}\itemsep=0pt
73 \section{ifinfo}\label{ifinfo}\index{ctsimtext,ifinfo}%
75 Displays information about an imagefile.
78 \begin{itemize}\itemsep=0pt
86 \section{phm2pj}\label{phm2pj}\index{ctsimtext,phm2pj}%
87 Simulates collection of X-rays data (projections) around a phantom object.
90 phm2pj projection-file-name number-of-detectors number-of-views [options...]
91 \begin{itemize}\itemsep=0pt
93 Select a standard phantom
94 \begin{itemize}\itemsep=0pt
102 Load a phantom definition definition
105 \begin{itemize}\itemsep=0pt
112 Number of samples per each detector
115 Sets the rotation amount as a multiple of pi. For parallel geometries use
116 a rotation angle of 1 and for equilinear and equiangular geometries use a rotation angle of 2.
118 \item --field-of-view
119 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.
122 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.
125 The Herman phantom is taken with permission from Gabor Hermans 1980 book\cite{HERMAN80}. The Shepp-Logan phantom was published in 1974\cite{SHEPP74}.
127 \section{phm2if}\label{phm2if}\index{ctsimtext,phm2if}%
128 Converts a geometric phantom object into an imagefile. The size of the
129 imagefile in pixels must be specified as well as the number of samples
130 to average per pixel.
133 \begin{itemize}\itemsep=0pt
137 \section{pj2if}\label{pj2if}\index{ctsimtext,pj2if}%
138 Convert a projection file into an imagefile.
141 \begin{itemize}\itemsep=0pt
142 \item --help Print brief online help
145 \section{pjinfo}\label{pjinfo}\index{ctsimtext,pjinfo}%
146 Displays information about a projection file.
149 \begin{itemize}\itemsep=0pt
157 \section{pjrec}\label{pjrec}\index{ctsimtext,pjrec}%
158 Reconstructs the interior of an object from a projection file.
162 \twocolitemruled{{\bf Parameter}}{{\bf Options}}
163 \twocolitem{{\bf --filter}}
164 {Selects which filter to apply to each projection. To properly reconstruct an image, this filter should be multiplied
165 by the absolute value of distance from zero frequency.
166 \begin{itemize}\itemsep=0pt
172 \twocolitem{{\bf --filter-parameter}}{Sets the alpha level for Hamming
173 window. At setting of 0.54, this equals the Hanning window.}
175 \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.
176 \begin{itemize}\itemsep=0pt
185 \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.
186 \begin{itemize}\itemsep=0pt
188 \item inverse-fourier
191 \twocolitem{{\bf --interpolation}}{Interpolation technique. {\tt linear} is optimal.
192 \begin{itemize}\itemsep=0pt
197 \twocolitem{{\bf -backprojection}}{Selects the backprojection technique. A setting of {\tt idiff3} is optimal.
198 \begin{itemize}\itemsep=0pt
207 \twocolitem{{\bf --zeropad}}{ Zeropad factor. A setting of {\tt 1} is optimal.}
209 \twocolitem{{\bf --preinterpolate}}{Selects preinterpolation interpolation technique and sets the preinterpolation factor. Currently, this is experimental and does not work well.}