pjrec(1)

✨ pjrec(1) — the reconstruction bestie ✨

okay so real talk, this is the pjrec page from the Engineering manual, section 1, and it's literally the tool that takes your projection data and ✨manifest✨ your image back into existence. no cap.

🌸 NAME 🌸

pjrec — reconstruction from projections. it's giving "put the object back together from its shadows" energy 💅

🦋 SYNOPSIS 🦋

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

💖 DESCRIPTION 💖

so here's the vibe: pjrec takes projection data from raysum-fileP and produces an (IF) image file, image-file, that's nx-image by ny-image pixels big, and inside that file is the reconstructed image. that's it. that's the whole girlboss moment. 🎀

✨ OPTIONS ✨

pjrec accepts the following options, and they're all about controlling the reconstruction algorithm. pick your faves 🫶

• --interp — interpolation method during backprojection
  • nearest — nearest neighbor interpolation
  • linear — linear interpolation
• --preinterpolate — preinterpolation factor (default = 1). bestie, this one is used only with frequency-based filtering, don't come for me
• --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 💜

ngl the lore goes deep. 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. vintage icon behavior fr fr.

🌈 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)

and that's the whole page, bestie 🎀 this one's from the Engineering manual, section 1, signed off by Kevin Rosenberg, and yes it really is called pjrec(1). go reconstruct something iconic 💅✨