+.\" -*- NROFF -*-
+.TH pjrec 1
+
+.SH NAME
+pjrec - reconstruction from raysum projections
+
+.SH SYNOPSIS
+.B pjrec projection-file image-file nx-image ny-image [OPTIONS]
+
+.SH DESCRIPTION
+\fIpjrec\fP takes projection data from \fIraysum-file\P and produces an
+(IF) image file \fIimage-file\fP, of size \fInx-image\fP by
+\fIny-image\fP pixels, containing the reconstructed image.
+
+.SH OPTIONS
+\fIpjrec\fP accepts the following options, which control the
+reconstruction algorithm:
+.TP 12
+.B \-\-interp
+Interpolation method during backprojection
+.RS
+.TP
+.B nearest
+Nearest neighbor interpolation
+.TP
+.B linear
+Linear interpolation
+.RE
+.TP 12
+.B \-\-preinterpolate
+Preinterpolation factor (default = 1). Used only with frequency-based
+filtering
+.TP 12
+.B \-\-filter
+Filter name
+.RS
+.TP 15
+.B abs_bandlimit
+Abs * Bandlimiting (default)
+.TP 15
+.B abs_sinc
+Abs * Sinc
+.TP 15
+.B abs_cosine
+Abs * Cosine
+.TP 15
+.B abs_hamming
+Abs * Hamming
+.TP 15
+.B shepp
+Shepp-Logan
+.TP 15
+.B bandlimit
+Bandlimiting
+.TP 15
+.B sinc
+Sinc
+.TP 15
+.B cosine
+Cosine
+.TP 15
+.B triangle
+Triangle
+.TP 15
+.B hamming
+Hamming
+.RE
+.TP 12
+.B \-\-filter-method
+Filter method before backprojections
+.RS
+.TP 15
+.B convolution
+Spatial filtering (default)
+.TP 15
+.B fourier
+Frequency filtering with discete fourier
+.TP 15
+.B fourier_table
+Frequency filtering with table lookup fourier
+.TP 15
+.B fft
+Fast Fourier Transform
+.RE
+.TP 12
+.B \-\-zeropad n
+Set zeropad level (default = 0). set n to number of powers to two to pad
+.TP 12
+.B \-\-filter-generation
+Filter Generation mode
+.RS
+.TP 12
+.B direct
+Use direct filter in spatial or frequency domain (default)
+.TP 12
+.B inverse_fourier
+Use inverse fourier transform of inverse filter
+.RE
+.TP 12
+.B \-\-backproj
+Backprojection Method
+.RS
+.TP
+.B trig
+Trigometric functions at every point
+.TP
+.B table
+Trigometric functions with precalculated table
+.TP
+.B diff
+Difference method
+.TP
+.B diff2
+Optimized difference method (default)
+.TP
+.B idiff2
+Optimized difference method with integer math
+.TP
+.B idiff3
+Highly-optimized difference method with integer math
+.RE
+.TP 12
+.B \-\-filter-param
+Alpha level for Hamming filter
+.TP 12
+.B \-\-trace
+Set tracing to level:
+.RS
+.TP 12
+.B none
+No tracing (default)
+.TP 12
+.B console
+Text level tracing
+.TP 12
+.B phantom
+Trace phantom
+.TP 12
+.B proj
+Trace allrays
+.TP 12
+.B plot
+Trace plotting
+.TP 12
+.B clipping
+Trace clipping
+.RE
+.TP 12
+.B \-\-verbose Turn on verbose mode
+.TP 12
+.B \-\-debug Turn on debug mode
+.TP 12
+.B \-\-version Print version
+.TP 12
+.B \-\-help Print a terse help message