+
+\subsection{File - Properties}
+
+\subsection{Process - Convert Polar Dialog}\label{convertpolardialog}
+The parameters are \texttt{xsize}, \texttt{ysize}, and \texttt{interpolation}.
+The \texttt{xsize} and \texttt{ysize} parameters set the size of the
+resulting image file. The \texttt{interpolation} parameter selects the
+interpolation method. Currently, the \texttt{bilinear} option provides
+the highest quality interpolation.
+
+\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}
+This dialog sets the parameters for reconstructing an image from projections
+using the Filtered Backprojection technique.
+
+
+\begin{twocollist}
+\twocolitemruled{\textbf{Parameter}}{\textbf{Options}}
+\twocolitem{\textbf{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{\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 convolution
+\item fourier
+\item fourier\_table
+\item fftw
+\item rfftw
+\end{itemize}
+}
+
+\twocolitem{\textbf{Interpolation}}{Interpolation technique.
+\texttt{cubic} is optimal when many projections are taken and the
+data is smooth. Otherwise, \texttt{linear} gives better results.
+Linear is also much 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 trig
+\item table
+\item diff
+\item idiff
+\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 direct
+\item inverse-fourier
+\end{itemize}
+}
+
+\twocolitem{\textbf{Zeropad}}{Zeropad factor when using
+frequency-based filtering. A setting of \texttt{1} is optimal.}
+
+\end{twocollist}