(registered 2023-06-12, last updated 2023-06-12)

Media type name: image

Media subtype name: j2c

Required parameters: N/A.

Optional parameters: N/A.

Encoding considerations: binary

   Single JPEG 2000 codestream, whose structure is specified in Rec. 
   ITU-T T.800 | ISO/IEC 15444-1.

Security considerations: JPEG 2000 codestreams contain structures of 
   variable length and have an extensible syntax. Both of these 
   aspects present potential security risks for implementations. In 
   particular, variable length structures present buffer overflow 
   risks and extensible syntax could result in the triggering of 
   adverse actions.

Interoperability considerations: A JPEG 2000 codestream can use 
   capabilities from any part of Rec. ITU-T T.8xx series | ISO/IEC 
   15444. The capabilities required to process the codestream are 
   specified by a combination of the Rsiz parameter and the value of 
   the CAP marker segment (see Rec. ITU-T T.800 | ISO/IEC 15444-1). 
   In addition, a JPEG 2000 codestream does not contain information 
   on the colourspace of the image. This information is implied or 
   provided out-of-band.

Published specification: Rec. ITU-T T.8xx series | ISO/IEC 15444

Applications which use this media: Multimedia and scientific

Fragment identifier considerations: None

Restrictions on usage: None

Additional information:

   1. Deprecated alias names for this type: N/A
   2. Magic number(s): Starts with the byte sequence: 0xFF 0x4F 0xFF 
      0x51
   3. File extension(s): j2c, J2C, j2k, J2K
   4. Macintosh file type code: N/A
   5. Object Identifiers: N/A

General Comments: This media type refers to a data payload that 
   consists of a single JPEG 2000 codestream that can contain 
   capabilities from any part of ISO/IEC 15444. This data payload, 
   and the file extensions "j2c" and "j2k" when the data payload is 
   stored in a file, are in widespread use.

Person to contact for further information:

   1. Name: ISO/IEC JTC 1/SC 29/WG 1 Convenor
   2. Email: sc29-sec&itscj.ipsj.or.jp

Intended usage: COMMON

Author/Change controller: ITU-T & ISO/IEC JTC 1