About .jp2 graphic file:

JP2 is the file extension for the new image format called JPEG2000 based on state-of-the-art wavelet compression. The JPEG2000 architecture advances a number of different applications in the digital imaging market, everything from digital cameras, pre-press, medical imaging and other key sectors.
JPEG2000, is a published international ISO standard (ISO 15444). It offers both lossless and lossy compression and provides much better image quality at smaller filesizes than JPG does.

Help how to open JP2 files:

Use Nero PhotoSnap