Format

Raw JPEG Stream

Summary

Name

Raw JPEG Stream

Identifiers

• Library of Congress Format Description Identifier: fdd000017
• PUID: fmt/41
• MIME: image/jpeg

Format type

Image (Raster)

Description

Raw JPEG Stream represents JPEG bitstream sequence of digital objects. JPEG stands for Joint Photographic Experts Group, an international organization that standardized the concept of lossy compression during the late 1980s and early 1990s. It uses DCT (Discrete Cosine Transform) compression technique used for images and audio. The standard of lossy compression is able to remove some visual data invisible to human eye which averages out colour variation and reduces the file size. JPEG image consists of a sequence of segments, each beginning with a two-byte "marker", each of which begins with a 0xFF byte, followed by a byte indicating what kind of marker it is. The signature for this entry represents the first two bytes of every JPEG stream, which are the Start Of Image (SOI) marker with values of 0xFF and 0xD8 (indicating that the baseline is DCT-based) and the End of Image (EOI) marker with valued of 0xFF and 0xD9. The second signatures represents the "colour transform" field of the APP14 which is an "Adobe" segment, representing graphic files which may have been edited in Adobe applications such as Adobe Photoshop.

Format encoding

Binary

Note

https://www.loc.gov/preservation/digital/formats/fdd/fdd000017.shtml#:~:text=The%20Library%20of%20Congress%20Recommended,specify%20a%20version%20of%20JPEG. https://web.archive.org/web/20220624201809/https://www.adobe.com/creativecloud/file-types/image/raster/jpeg-file.html https://web.archive.org/web/20221015163305/https://en.wikipedia.org/wiki/JPEG

File extensions

jpe, jpg, jpeg, jif, jfif, jfi

Submitted by

Digital Preservation Department / The National Archives

Relationships

Has lower priority than

• JPEG File Interchange Format 1.00
• JPEG File Interchange Format 1.01
• JPEG File Interchange Format 1.02
• Still Picture Interchange File Format 1.0
• Exchangeable Image File Format (Compressed) 2.1
• Exchangeable Image File Format (Compressed) 2.2
• Exchangeable Image File Format (Compressed) 2.0
• Exchangeable Image File Format (Compressed) 2.21
• Exchangeable Image File Format (Compressed) 2.3.x

Internal signatures

Changelog

• V114

  Release date

  22 August 2023

  • Updated

    Raw JPEG Stream: Offset modified for the EOF signature as null value causing max-offset to be ignored. Submitted by Preservica.

• V109

  Release date

  1 November 2022

  • Updated

    Raw JPEG Stream: Updated description and reference links, added extensions jif; jfif; jfi, and LoC identifier. Submitted by Digital Preservation Department, The National Archives (UK).

• V75

  Release date

  17 July 2014

  • Updated

    Raw JPEG Stream: EOF offset increased. Submitted by Public Record Office of Northern Ireland.

• V63

  Release date

  29 August 2012

  • Updated

    Raw JPEG Stream: Signature refined through PRONOM Research in collaboration with the National Library of New Zealand.

• V62

  Release date

  28 August 2012

  • Updated

    Raw JPEG Stream: Existing signature refined through PRONOM Research.