Once Java is installed, the following additional steps are needed: After downloading ImageJ, if Java has not been installed, you will be asked to download and install Java.
The default installation of OS X Yosemite (OS X 10.10) and greater does not include key files required for compiling and running plugins that require QuickTime for Java. QTJ manual installation under OS X Yosemite and El Capitan Please head to the Microscopy page for more information. Instead, it may be easier to use plugins under ImageJ to import QuickTime movies using Ffmpeg, which will work on 64-bit operating systems and under newer, 64-bit versions of ImageJ. I (Jeff) have successfully tested Mojave with VMWare Fusion. It is possible to use virtualization software to run OS X Mojave or earlier, to retain support for QTJ. Due to its 32-bit architecture, it will not work under 64-bit only operating systems like OS X Catalina. NOTE: QuickTime for Java (QTJ) has been deprecated for many years by Apple.