The file extension MJP2 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 MJP2 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 MJP2 is more common under Apple Mac OSX. On Windows, the mj2 extension is more commonly used for these types of files.
Some programs can read these files with the help of a plugin.