FSLCHFILETYPE(1)

✨ fslchfiletype ✨

okay bestie, gather round, because fslchfiletype is one of those little FSL besties that does exactly one thing and does it flawlessly 💅 it's the file-type glow-up tool, and honestly? iconic.

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🎀 SYNOPSIS 🎀

fslchfiletype <filetype> <filename> [filename2]

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💖 DESCRIPTION 💖

so here's the tea, bestie: fslchfiletype changes the file type of the image file — or, if you're feeling spicy and want to keep the original around, it copies to a new file 🌸

lowkey the <filetype> argument is not a vibe-you-can-improvise situation. it only accepts the exact values listed below, no cap.

the valid values for filetype are:

NIFTI NIFTI_GZ NIFTI_ZST NIFTI_BZ2 NIFTI_PAIR NIFTI_PAIR_GZ
NIFTI_PAIR_ZST NIFTI_PAIR_BZ2 NIFTI2 NIFTI2_GZ NIFTI2_ZST
NIFTI2_BZ2 NIFTI2_PAIR NIFTI2_PAIR_GZ NIFTI2_PAIR_ZST
NIFTI2_PAIR_BZ2

like… look at that list 👑 you got your classic NIFTI, all the compressed girlies (NIFTI_GZ, NIFTI_ZST, NIFTI_BZ2), the .hdr/.img pair era with NIFTI_PAIR and its compressed sisters (NIFTI_PAIR_GZ, NIFTI_PAIR_ZST, NIFTI_PAIR_BZ2), and then the whole NIFTI-2 cinematic universe doing the exact same thing again with a 2 in the name: NIFTI2, NIFTI2_GZ, NIFTI2_ZST, NIFTI2_BZ2, NIFTI2_PAIR, NIFTI2_PAIR_GZ, NIFTI2_PAIR_ZST, NIFTI2_PAIR_BZ2 ✨

pick one, hand it your filename, and if you're copying instead of converting in place, slide that filename2 in there too 🫶

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and that's the whole page, bestie. short, sweet, does its job, ate and left no crumbs 🍓

this was fslchfiletype version 3.29.1, dropped August 2026 — shoutout to the FSL crew for it 💜 mwah, bye!! 💖✨🦋