False Color Composer

runs 100% in your browser — nothing uploaded

Compose a false-color image from two source frames (e.g. VIS + IR). Channels are auto-aligned before compositing.

Homemade by alivenine. If you find any bugs or errors, please bear with it or report them to me at me@alivenine.fyi, and hopefully I'll fix them someday.

1 — Load images

Image 1

no file

Image 2

no file

2 — Assign channels

Advanced — channel registration runs automatically by default

R and B channels are auto-aligned to G before compositing. Override the method, or turn it off if your channels are already pixel-registered.

Enable image registration

3 — Compose & export

Loading OpenCV…

About this tool & its limits

Everything runs client-side in WebAssembly — your images never leave this device, and nothing needs a server.
TIFF files are read directly (not through the browser's normal image decoder, which mostly can't open TIFF at all) — real 16-bit sensor data stays 16-bit all the way through registration; only TIFF export can carry that precision out, since PNG/JPG go through the browser's 8-bit-only canvas.
Browsers cap canvas dimensions at roughly 16,384 px per side. Source images above that are read in tiles instead of being rejected, so loading still works — but if the composed result itself exceeds that size (or is 16-bit), only TIFF export can carry it at full resolution/precision (PNG/JPG are disabled for that result; the on-screen preview is shown downscaled).
Very large frames (100+ MP) can take several seconds and up to a couple GB of memory to load, align and compose — expect a wait, not a freeze. An absurdly large file (500+ MP) is refused outright with a clear message rather than risking a tab crash.
Registration is translation/affine only (feature matching, cross-correlation, or intensity-based) — it does not correct lens distortion or perspective.
JPEG export is lossy (85% quality by default) and always 8-bit. For quantitative or scientific use, export TIFF instead — it's uncompressed and carries the composite's real bit depth (8 or 16), single strip, no multi-page.