sympl(1)

📦
version 3.3.1p2 · 7 versions
, in ubuntu stonking

✨ NAME ✨

sympl — the symmetry plane computation era, and yes she's the main character 💅

So the tool is called sympl, it lives in the Computational Morphometry Toolkit (that's CMTK bestie, get familiar 🫶), and her whole job is figuring out where your image's symmetry plane is at.

🌸 SYNOPSIS 🌸

sympl InputImage

One input image, that's it, that's the vibe. 😌

🦋 DESCRIPTION 🦋

Okay so here's the tea: sympl computes the approximate symmetry plane of an image. Think of the mid-sagittal plane in human brain images — the imaginary mirror line that your brain thinks it has. This tool finds it. Lowkey iconic. 🧠✨

And she doesn't just compute it and ghost you. Various forms of output are supported, like:

  • writing the input image with the symmetry plane drawn into it 🖍️
  • writing the input image realigned along the symmetry plane

Pick your fave, she's flexible.

👑 OPTIONS 👑

💖 Global Toolkit Options (these are shared by all CMTK tools)

Every single CMTK tool has these, so this is like the group chat that everybody's in.

  • --help — spits out the list of basic command line options to standard output.
  • --help-all — spits out the complete list, basic AND advanced, to standard output. The full lore dump.
  • --wiki — writes the list of command line options to standard output in MediaWiki markup. For the wiki girlies.
  • --man — writes man page source in 'nroff' markup to standard output. Yes, the man page can generate a man page. She contains multitudes.
  • --xml — writes the command line syntax specification in XML markup, specifically for Slicer integration.
  • --version — writes the toolkit version to standard output. Vibe check the build. ⭐
  • --echo — writes the current command line to standard output, so you can see exactly what you typed and be like "not me doing that 🙈".
  • --verbose-level <integer> — set verbosity level. Your girl can talk more or less, you control the dial.
  • --verbose, -v — increment verbosity level by 1. ⚠️ Heads up: this one is deprecated, it's only kept around for backward compatibility, so ngl use --verbose-level if you can.
  • --threads <integer> — set the maximum number of parallel threads, for POSIX threads and OpenMP. She goes multi-core, she's booked and busy. 🔥

💜 Optimization

  • --accuracy <double>, -a <double> — Accuracy, a.k.a. the final optimization step size in [mm]. [Default: 0.1]
  • --sampling <double>, -s <double> — Resampled image resolution. This is the resolution [in mm] of the first (finest) resampled image in the multi-scale pyramid, which is derived straight up from the original full-resolution images. [Default: 1]
  • --levels <integer>, -l <integer> — Number of resolution levels. The algorithm creates (levels-1) resampled images with increasingly coarse resolution and uses them in successive order of increasing resolution, before it finally uses the original images at the final level. [Default: 4]

🌈 Initial approximate symmetry plane orientation

  • --initial-plane — Initial orientation of the symmetry plane. Bestie, this should be the closest orthogonal plane to the expected actual symmetry plane. Supported values: "initial-axial", "initial-coronal", "initial-sagittal", "initial-xy", "initial-xz", "initial-yz", where the default is "initial-sagittal". Or just use one of these instead:
    • --initial-axial — Approximately axial symmetry
    • --initial-coronal — Approximately coronal symmetry
    • --initial-sagittal — Approximately sagittal symmetry [This is the default]
    • --initial-xy — Approximately XY plane symmetry
    • --initial-xz — Approximately XZ plane symmetry
    • --initial-yz — Approximately YZ plane symmetry [This is the default]
Not me noticing the page calls initial-sagittal the default and tags --initial-yz as the default 💀 just pass your plane explicitly and you're golden, no cap.

🎀 Pre-computed symmetry

If you already know the symmetry parameters, why make her search again? Skip the whole quest.

  • --output-only <string> — give symmetry parameters [Rho Theta Phi] as an option and skip the search entirely. [Default: disabled]
  • --output-only-file <string> — read symmetry parameters from a file and skip the search. [Default: disabled]

🍓 Data pre-processing

  • --min-value <float> — force the minimum data value. [Default: disabled]
  • --max-value <float> — force the maximum data value. [Default: disabled]

💅 Output of Images

  • --interpolation — the interpolation method used for reformatted output data. Supported values: "linear", "cubic", "sinc", where the default is "linear". Or use one of these:
    • --linear, -L — use linear image interpolation for output. [This is the default]
    • --cubic, -C — use cubic image interpolation for output.
    • --sinc, -S — use cosine-windowed sinc image interpolation for output.
  • --pad-out <double>, -P <double> — padding value for output images. [Default: disabled]
  • --mark-value <double> — data value used to mark (draw) the symmetry plane. [Default: 4095]
  • --write-marked <image-path> — file name for the output image with the marked symmetry plane. [Default: NONE]
  • --write-aligned <image-path> — file name for the symmetry plane-aligned output image. [Default: NONE]
  • --mark-aligned — mark the symmetry plane in the aligned output image.
  • --write-subtract <image-path> — file name for the mirror subtraction image. [Default: NONE]
  • --write-mirror <image-path> — file name for the image mirrored w.r.t. the symmetry plane. [Default: NONE]

⭐ Output of Parameters

  • --outfile <path>, -o <path> — file name for the symmetry plane parameter output. [Default: NONE]
  • --write-xform <transformation-path> — write the affine alignment transformation to a file. [Default: NONE]

🫶 AUTHORS 🫶

Torsten Rohlfing, with contributions from Michael P. Hasak, Greg Jefferis, Calvin R. Maurer, Daniel B. Russakoff, and Yaroslav Halchenko. Collab queens, shoutout to the whole squad. 👑

📜 LICENSE 📜

http://www.fsf.org/licensing/licenses/gpl.html — yeah she's GPL, read up.

💀 BUGS 💀

Found a bug? Not a vibe, but report it at http://nitrc.org/projects/cmtk/ and they'll handle it.

🌟 ACKNOWLEDGMENTS 🌟

CMTK is developed with support from the NIAAA under Grant AA021697, National Consortium on Alcohol and Neurodevelopment in Adolescence (N-CANDA): Data Integration Component.

And from April 2009 through September 2011, CMTK development and maintenance was supported by the NIBIB under Grant EB008381. She's been funded, she's been fed, she's thriving. 💖

Okay that's the whole page bestie, go find some symmetry planes and slay ✨ This was CMTK 3.3.1p2, dated Jun 24 2026 — mwah, bye! 💅🌸

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