+
+\subsection{File - Properties}
+The displayed properties include:
+
+\begin{itemize}
+\item Number of detectors in the projections
+\item Number of views
+\item The variables used when generating the projections from the phantom
+\end{itemize}
+
+\subsection{Process - Convert Polar Dialog}\label{convertpolardialog}\index{Polar conversion}
+Creates an image file with the polar conversion of the projection data. The options to set are:
+
+\begin{twocollist}
+\twocolitem{\textbf{xsize}}{Number of columns in output image.}
+\twocolitem{\textbf{ysize}}{Number of rows in output image.}
+\twocolitem{\textbf{interpolation}}{Selects the interpolation method.
+Currently, the \texttt{bilinear} option provides the highest
+quality interpolation.}
+\end{twocollist}
+
+\subsection{Process - Convert FFT Polar Dialog}
+The parameters for this option are the same as \helprefn{Convert
+Polar Dialog}{convertpolardialog}. For this command, though, the
+projections are Fourier transformed prior to conversion to polar
+image.
+
+\subsection{Reconstruct - Filtered Backprojection Dialog}\index{Reconstruction dialog}
+This dialog sets the parameters for reconstructing an image from projections
+using the Filtered Backprojection technique.
+
+
+\begin{twocollist}
+\twocolitem{\textbf{Filter}}{Selects which filter to apply to each
+projection. To properly reconstruct an image, this filter should
+be consist of the the absolute value of distance from zero
+frequency optionally multiplied by a smoothing filter. The optimal
+filters to use are:
+\begin{itemize}\itemsep=0pt
+\item \texttt{abs\_bandlimit}
+\item \texttt{abs\_cosine}
+\item \texttt{abs\_hamming}
+\end{itemize}
+} \twocolitem{\textbf{Hamming parameter}}{Sets the alpha level for
+Hamming window. At setting of 0.54, this equals the Hanning
+window.}
+
+\twocolitem{\textbf{Filter Method}}{Selects the filtering method.
+For large numbers of detectors, \texttt{rfftw} is optimal. For
+smaller numbers of detectors, \texttt{convolution} might be a bit
+faster.
+\begin{itemize}\itemsep=0pt
+\item \texttt{convolution}
+\item \texttt{fourier} - Uses simple Fourier transform.
+\item \texttt{fourier-table} - Optimizes Fourier transform by precalculating trigometric functions.
+\item \texttt{fftw} - Uses complex-valued Fourier transform with the \emph{fftw} library.
+\item \texttt{rfftw} - Uses optimized real/half-complex Fourier transform.
+\end{itemize}
+}
+
+\twocolitem{\textbf{Interpolation}}{Interpolation technique.
+\texttt{cubic} is optimal when the
+data is smooth. Smooth data is obtained by taking many projections and/or
+using a smoothing filter. In the absence of smooth data, \texttt{linear} gives better results and
+is many times faster than cubic interpolation.
+
+\begin{itemize}\itemsep=0pt
+\item nearest
+\item linear
+\item cubic
+\end{itemize}
+}
+\end{twocollist}
+
+\subsection{Advanced Options}
+
+These options are only visible if \emph{Advanced Options} has been
+selected in the \texttt{File - Preferences} dialog. These parameters
+default to optimal settings and don't need to be adjusted except
+by expert users.
+
+\begin{twocollist}
+\twocolitem{\textbf{Backprojection}}{Selects the backprojection
+technique. A setting of \texttt{idiff} is optimal.
+\begin{itemize}\itemsep=0pt
+\item \texttt{trig} - Use trigometric functions at each image point.
+\item \texttt{table} - Use precalculated trigometric tables.
+\item \texttt{diff} - Use difference method to iterate within image.
+\item \texttt{idiff} - Use integer iteration math.
+\end{itemize}
+}
+
+\twocolitem{\textbf{Filter Generation}}{Selects the filter
+generation. With convolution, \texttt{direct} is the proper method
+to select. With any of the frequency methods,
+\texttt{inverse-fourier} is the best method.
+\begin{itemize}\itemsep=0pt
+\item \texttt{direct}
+\item \texttt{inverse-fourier}
+\end{itemize}
+}
+
+\twocolitem{\textbf{Zeropad}}{Zeropad factor when using
+frequency-based filtering. A setting of \texttt{1} is optimal whereas
+a setting of \texttt{0} disables zero padding.}
+
+\end{twocollist}