Installation of AstroImageJ on Mac OSX

The files in this directory are for installing the latest of AstroImageJ on Linux, Windows, and Mac operating systems. The files are complete and do not require a previous installation of ImageJ or AstroImageJ.

If you already have installed version 2.0 of AIJ or later, simply use the update option on the AIJ toolbar 'Help' menu to have the most recent version. The user will need write permission to the directory where the software is installed to use this feature.

For more information and help, please see the

One-step AIJ installation is not directly compatible with OS X 10.12, 10.13, or 10.14+. There are currently two procedures that are tested to work. The simplest is only requires a command to be executed in a terminal window:

1. Download the latest installation file.
2. Unzip the installation file and move the AstroImageJ folder to the Applications folder
3. Run this command in Terminal

xattr -r -d com.apple.quarantine /Applications/AstroImageJ

1. If you haven't already, Install AIJ by unzipping the install file and dragging the resulting AstroImageJ folder to the Applications folder.
2. Open the Terminal app from the /Applications/Utilities/ folder and then enter the following command syntax: sudo spctl --master-disable
3. Hit return and authenticate with an admin password.
4. Relaunch System Preferences and go to the Security → Privacy → General tab.
5. You will now see the Anywhere option under Allow apps downloaded from:. Select this option.
6. Make a copy of /Applications/AstroImageJ/AstroImageJ64.app on the desktop. An easy way to do that is hold down the alt key while dragging AstroImageJ64.app from the /Applications/AstroImageJ folder to the desktop.
7. Delete the original copy of AstroImageJ64.app that is still in the /Applications/AstroImageJ folder.
8. Drag the copy of AstroImageJ64.app from the desktop back to the /Applications/AstroImageJ folder.
9. Start AIJ and set up your memory settings as needed.
10. Close AIJ.
11. After running AIJ the first time, enter the following command syntax to reenable GateKeeper (AIJ will continue to work normally): sudo spctl --master-enable

After installation you should allocate the memory your uses will need, and check for AstroImageJ updates. Both of these can be done at any time, and the updates will keep your installation current with bug fixes and new features.

• You may need to increase the amount of memory allocated to AIJ using AIJ_Toolbar->Edit->Options->Memory & Threads. Enter the amount of memory in MB that you want allocated to AIJ. It is recommended to NOT exceed 2/3 of the physical memory installed in your system. For example, if your machine has 8 GB of memory, enter a memory size up to ~5500 MB.
• Click "OK" and close AIJ. Restart AIJ to use the new memory settings.
• Finally, upgrade to the latest version of AIJ by using the built-in update feature. Go to AIJ_Toolbar->Help->Update AstroImageJ. The "Upgrade To:" box will default to the latest version of AIJ. Click "OK" and three files will be downloaded and installed in the proper location in the installation directory structure (again, you need write access to the installation directory). After the files have been installed, AIJ will automatically close.
• Restart AIJ to use the updated version.

On the Mac with this installation procedure AIJ can be started by double-clicking either the AstroImageJ.app or the AstroImage64.app icons. Either app can be dragged to the Dock to provide convenient access for starting AIJ.