Re: [media-types] [IANA #1272547] image/j2c registration request

[Darrel Miller <[e-mail]>]

Amanda,

I have reviewed this submission and it looks good to me.  However, it is not clear to me why this is marked as provisional.  From what I can tell the standard was published in 2019.  It doesn't appear like this needs to be a provisional registration.

Darrel

________________________________
From: Amanda Baber via RT <[e-mail]>
Sent: Monday, May 15, 2023 8:05:02 PM
Cc: Darrel Miller <[e-mail]>; [e-mail] <[e-mail]>
Subject: [IANA #1272547] image/j2c registration request

Hi Darrel,

Can you review this new standards tree request by the 29th? Both of the organizations named in the change controller field are listed at https://www.iana.org/assignments/iesg-recognized-organizations.

thanks,
Amanda

=====

Name: Pierre-Anthony Lemieux

Email: [e-mail]

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

Provisional registration? (standards tree only): Yes

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: [e-mail]

Intended usage: COMMON

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