1. Install Fiji#
Fiji is ImageJ with a large collection of scientific plugins already installed. You want Fiji, not plain ImageJ: the course uses plugins that only Fiji ships with.
Download#
Get it from fiji.sc/#download and pick the version for your operating system.
Fiji runs from the folder where you unpack it. Place that folder somewhere you can find again, such as your home directory.
Warning
On macOS the first launch might be blocked. If you see “Fiji cannot be opened because the developer cannot be verified”, right-click the app and choose Open, then confirm. Double-clicking might keep failing.
Check it works#
Start Fiji. Its main window is a narrow toolbar.
File ▸ Open Samples ▸ Blobsopens a test image.