fit_spline_xform(1)

📦
version 3.3.1p2 · 7 versions
, in ubuntu stonking

💖 fit_spline_xform — the manual, but make it make sense 💖

okay bestie, so this is fit_spline_xform, one of the CMTK tools (that's the Computational Morphology Toolkit, iykyk). It lives in the same manual family as every other CMTK command, section 1, and it is genuinely one of the most ✨useful✨ little gremlins in the whole toolkit. Let's get into it.

✨ NAME ✨

fit_spline_xform — Fit Single B-Spline Transformation to Concatenated Transformation List

like. the name says it all fr fr. one spline. one list that's been smooshed together. we're fitting. we're slaying.

🦋 SYNOPSIS 🦋

fit_spline_xform InputImage XformList

two args, that's the whole vibe. InputImage and XformList, and the tool does the rest. periodt.

🌸 DESCRIPTION 🌸

okay so here's the tea 🫖 — this tool fits a parametric nonrigid transformation (that's a B-spline free-form deformation, bestie) to a list of concatenated transformations, which are optionally inverted.

that's it, that's the whole job. you hand it a stack of transforms that have already been glued together, and it produces one single smooth spline that approximates the whole situation. iconic behavior honestly. 💅

✨ OPTIONS ✨

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

these ones show up in literally every CMTK tool, so if you've read one manpage you've lowkey read them all. they're the group-chat regulars. 💖

  • --help — writes the list of basic command line options straight to standard output. the "just tell me the basics" button.
  • --help-all — writes the complete list of both basic and advanced command line options to standard output. for when you want the whole lore drop.
  • --wiki — writes the list of command line options to standard output in MediaWiki markup. wiki girlies, this one's for you.
  • --man — writes man page source in 'nroff' markup to standard output. yes it can write its own manpage. main character energy honestly.
  • --version — writes the toolkit version to standard output.
  • --echo — writes the current command line to standard output. it's giving receipts. 🧾
  • --verbose-level <integer> — sets the verbosity level. pick a number, any number.
  • --verbose, -v — increments the verbosity level by 1. ⚠️ heads up bestie: this one is deprecated — it's only still here because it's supported for backward compatibility. so like, it works, but the vibe is dated.
  • --threads <integer> — sets the maximum number of parallel threads (for POSIX threads and OpenMP). go parallel, go fast. 🔥

🎀 Fitting Options 🎀

this is the actual main event, the meat of the situation, the reason we're all here.

  • --levels <integer> — number of levels in the multi-level B-spline approximation procedure. [Default: 1]
  • --fit-affine-first — fit an affine transformation first, then initialize the spline with it. a little warm-up stretch before the real workout. 💪
  • --final-cp-spacing <double> — final control point grid spacing of the output B-spline transformation. [Default: 0]
  • --final-cp-dims <string> — final control point grid dimensions (i.e., number of controlpoints) of the output B-spline transformation. You provide this as 'dimX,dimY,dimZ'. [Default: NONE]
ngl, --final-cp-spacing defaults to 0 and --final-cp-dims defaults to NONE — so if you don't tell it what you want, it's not gonna magically know. tell it what you want. communication is key. 💌

🍓 Input Options 🍓

  • --inversion-tolerance <double> — numerical tolerance of B-spline inversion, in mm. Smaller values lead to more accurate inversion, but may increase failure rate. [Default: 1e-08]
⚠️ ok so this is one of those "precision vs. vibes" tradeoffs. cranking the number down = more accurate but also more likely to just. fail. small number, fragile heart. 😭

🌈 Output Options 🌈

  • --output <transformation-path>, -o <transformation-path> — path for the output transformation. [Default: NONE]
default is NONE so bestie if you forget -o you're gonna get nowhere fast. set your output path, please, I am begging 🙈

💜 AUTHORS 💜

Torsten Rohlfing, with contributions from Michael P. Hasak, Greg Jefferis, Calvin R. Maurer, Daniel B. Russakoff, and Yaroslav Halchenko.

the whole squad pulled up for this one. 🫶

📜 LICENSE 📜

http://www.fsf.org/licensing/licenses/gpl.html

💀 BUGS 💀

Report bugs at http://nitrc.org/projects/cmtk/

(we love a tool that tells you where to complain. transparency queen. 👑)

🌟 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.

From April 2009 through September 2011, CMTK development and maintenance was supported by the NIBIB under Grant EB008381.

🎬 SEE ALSO 🎬

(no see-also refs here bestie, this page keeps it self-contained. we stan an independent woman. 💅)

and that's the whole page, babes. this was CMTK 3.3.1p2, dated Jun 24 2026, and honestly? it ate. now go fit that spline. you got this. 💖✨🦋🌸🎀💅🫶

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