NAME

       pjrec - reconstruction from projections

SYNOPSIS

       pjrec projection-file image-file nx-image ny-image [OPTIONS]

DESCRIPTION

       pjrec  takes projection data from raysum-fileP and produces an (IF) image file image-file,
       of size nx-image by ny-image pixels, containing the reconstructed image.

OPTIONS

       pjrec accepts the following options, which control the reconstruction algorithm:

       --interp    Interpolation method during backprojection

                   nearest
                          Nearest neighbor interpolation

                   linear Linear interpolation

       --preinterpolate
                   Preinterpolation  factor  (default  =  1).   Used  only  with  frequency-based
                   filtering

       --filter    Filter name

                   abs_bandlimit  Abs * Bandlimiting (default)

                   abs_sinc       Abs * Sinc

                   abs_cosine     Abs * Cosine

                   abs_hamming    Abs * Hamming

                   shepp          Shepp-Logan

                   bandlimit      Bandlimiting

                   sinc           Sinc

                   cosine         Cosine

                   triangle       Triangle

                   hamming        Hamming

       --filter-method
                   Filter method before backprojections

                   convolution    Spatial filtering (default)

                   fourier        Frequency filtering with discete fourier

                   fourier_table  Frequency filtering with table lookup fourier

                   fft            Fast Fourier Transform

       --zeropad n Set zeropad level (default = 0).  set n to number of powers to two to pad

       --filter-generation
                   Filter Generation mode

                   direct      Use direct filter in spatial or frequency domain (default)

                   inverse_fourier
                               Use inverse fourier transform of inverse filter

       --backproj  Backprojection Method

                   trig   Trigometric functions at every point

                   table  Trigometric functions with precalculated table

                   diff   Difference method

                   diff2  Optimized difference method (default)

                   idiff2 Optimized difference method with integer math

                   idiff3 Highly-optimized difference method with integer math

       --filter-param
                   Alpha level for Hamming filter

       --trace     Set tracing to level:

                   none        No tracing (default)

                   console     Text level tracing

       --verbose Turn on verbose mode

       --debug Turn on debug mode

       --version Print version

       --help Print a terse help message

AUTHORS

       Kevin Rosenberg, M.D. <kevin@ctsim.org>

HISTORY

       CTSim  was begun in 1983 using MS-DOS and an EGA display adapter. In 1999 it was ported to
       GNU/Linux and later ported to Microsoft Windows.

SEE ALSO

       ctsim(1) ctsimtext(1) if1(1) if2(1) ifinfo(1) linogram(1) phm2helix(1) phm2if(1) phm2pj(1)
       pj2if(1) pjHinterp(1) pjinfo(1)