geomatch(1)

💖 geomatch — the vibes check for your images 💖

okay bestie, welcome to geomatch(1) from the Computational Morphometry Toolkit (CMTK, if you're cool). This is the page for the geomatch command, and it's literally here to answer one question: do these images actually match each other or not.

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✨ NAME ✨

geomatch — check whether the geometries (like grid dimensions, pixel sizes, spatial coordinates) of two or more images match. yes, that's the whole job. and it's iconic.

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🌸 SYNOPSIS 🌸

geomatch ImagePaths

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🦋 DESCRIPTION 🦋

So the way this works: geomatch reads two or more images and tests whether their grid dimensions, their pixel sizes, and their image-to-space transformations all match. Like, are they actually the same shape and position in space, or are we being lied to.

Optionally, all the images get reoriented into standard orientation before the test even happens. very demure, very mindful.

Here's the vibe check result, and this part matters:

• If all images match, the tool exits with exit code 0. slay. everything is fine.
• If they don't all match, it exits with exit code 2. not a crash, just a "no ma'am."
• If there's an error (like, one of the images can't be read at all), the exit code is 1. 💀

fr fr, keep an eye on which code you get — 2 means "they don't match" and 1 means "something actually went wrong." those are two different problems bestie, don't mix them up.

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💅 OPTIONS 💅

🌈 Global Toolkit Options (these are shared by all CMTK tools, so you'll see them everywhere)

• --help — writes the list of basic command line options to standard output. the starter pack.
• --help-all — writes the complete list of basic and advanced command line options to standard output. the deluxe edition.
• --wiki — writes the list of command line options to standard output in MediaWiki markup. for when you're being wiki-pilled.
• --man — writes man page source in 'nroff' markup to standard output. meta, honestly.
• --version — writes the toolkit version to standard output. know your era.
• --echo — writes the current command line to standard output. receipts.
• --verbose-level <integer> — set the verbosity level. pick your yap amount.
• --verbose, -v — increment verbosity level by 1. ⚠️ deprecated, but supported for backward compatibility. she's retired but still showing up to the function.
• --threads <integer> — set the maximum number of parallel threads (for POSIX threads and OpenMP). let her multitask.

📥 Input Options

• --read-ras — read all images in RAS orientation.

🔍 Image Comparison Options

• --no-check-xforms — do not check transformation matrices. skipping that part, no judgment.
• --no-check-pixels — do not check pixelsizes. also skipping.
• --tolerance <double> — numerical tolerance for floating point comparisons of transformation matrices. [Default: 1e-06]
• --tolerance-xlate <double> — numerical tolerance for floating point comparisons of the translational components of the transformation matrices. [Default: 0.001]

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👑 AUTHORS 👑

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

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📜 LICENSE 📜

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

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🐛 BUGS 🐛

Report bugs at http://nitrc.org/projects/cmtk/. not me being the one to tell you, but if something's giving broken, that's where it goes.

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🌟 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. we love funding, we love science, periodt. 💜

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okay and that's the whole page bestie ✨ this little manual is from CMTK 3.3.1p2, dated Jun 24 2026, and it's the geomatch(1) page. go check your geometries, and remember: exit code 0 is the only vibe we're chasing 💖🎀🦋