JPEG 2000 codestream
From Just Solve the File Format Problem
Overview
JPEG2000 codestream (also known as J2K, J2C, or JPEG 2000 Part 1, Core Coding System) is the main compressed image format defined by the JPEG2000 standard. It may appear in a file by itself, or embedded in JP2 or another file format.
It uses a variant of JPEG format, with the same kind of markers and segments. This is unlike the JP2 headers, which use a completely different format.
See JP2 and JPEG2000 for more information.
Identification
Files start with bytes ff 4f ff.
