The file extension MJ2 marks an image sequence in the extended JPEG 2000 format. There are several enhancements of the JPEG 200 standard, which open up additional possibilities. The support for the extensions is not yet widespread and does not have to be complete for a program.
The MJ2 file contains a video that is a sequence of JPEG 2000 compressed frames. The file may also contain audio data.
JPEG 2000 is a digital image compression technique that provides both lossless and lossy compression. It has some advantages over JPEG. Image quality is better at high compression rates and some limitations no longer exist. Eg image size, color depths or support for alpha channels (for transparency). However, this is offset by the licensing-related situation and a significantly higher demand for computing power.
The ending MJ2 is more common under Windows. Other operating systems, such as Apple Mac OSX, often use the extension mjp2 for these types of files.
Some programs can read these files with the help of a plugin.
Most often resolving problems with opening MJ2 files is very simple. Just install an appropriate program that supports such files. All of the listed programs support MJ2 files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of MJ2 files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate MJ2 files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Adobe Premiere Pro applications is not on the list, select "Browse" option in order to manually locate the directory where Adobe Premiere Pro has been installed.
Sometimes problems with opening MJ2 files may not lie with the application itself, but can arise due to other causes, such as: