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JPEG File Interchange Format Family

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name JPEG File Interchange Format Family
Description

JPEG File Interchange Format Family (JFIF) is an image file format standard published as ITU-T recommendation T.871 and ISO/IEC 10918-5. JFIF defines a minimal container specification for image data encoded with the JPEG Image Encoding Family. In other words, JPEG file performs the encoding and JFIF wraps the JPEG encoding.

JFIF v1.02, introduced in 1992, is the most commonly used. Both versions 1.00 and 1.01 were available for less than one year before the release of 1.02. For more, see History and JPEG File Interchange Format, Version 1.02.

JFIF is entirely compatible with the standard JPEG interchange format with the only additional requirement is the mandatory presence of the APP0 (application) marker right after the SOI (start of image) marker.

The JFIF version is declared in the frame header: "you can identify a JFIF file by looking for the following sequence: X'FF', SOI, X'FF', APP0, [2 bytes to be skipped], "JFIF", X'00'".... in which "the most significant byte is used for major revisions, the least significant byte for minor revisions."

Production phase

May be applied in initial-state picture creation; often used for middle- and final-state archiving or end-user delivery.

Relationship to other formats
    Contains JPEG, JPEG Image Encoding Family
    Has subtype JFIF_1_02, JPEG File Interchange Format, Version 1.02
    Has subtype JFIF, JPEG File Interchange Format, Version 1.00. Not described separately at this time.
    Has subtype JFIF, JPEG File Interchange Format, Version 1.01. Not described separately at this time.
    May contain JPEG_DCT_BL, JPEG DCT Compression Encoding, Baseline
    May contain JPEG_DCT_PRG, JPEG DCT Compression Encoding, Progressive
    May contain JPEG_EXT, JPEG Compression Encoding, Extensions
    May contain JTIP, JPEG Tiled Image Pyramid Format, not described at this website at this time
    May contain JPEG_orig_LL, JPEG Original Lossless Compression (ISO/IEC 10918)
    May contain JPEG-LS, JPEG Lossless Compression (ISO/IEC 14495)

Local use Explanation of format description terms

LC experience or existing holdings See JPEG.
LC preference See JPEG. The Library of Congress Recommended Formats Statement (RFS) includes JPEG/JFIF as a preferred format for photographs in digital form, other graphic images in digital form and 2D and 3D Computer Aided Design raster images. The RFS does not specify a version of JFIF.

Sustainability factors Explanation of format description terms

Disclosure

Version 1.02 is fully disclosed as an open standard.

Version 1.01 was open and available as a specification.

Version 1.00 was shared among a small group of industry representatives during the development and public release of Version 1.01.

    Documentation

See: JPEG File Interchange Format, Version 1.02.

Adoption JFIF 1.02 is widely adopted. Versions 1.01 and 1.00 are less common, but due to the similarities between format versions, all have wide usage and support. See History for more information on version history.
    Licensing and patents No licensing or patents for the file format. See JPEG Image Encoding Family for information on patent claims on JPEG encoding.
Transparency JFIF structure is transparent but JPEG encoding may depend upon algorithms and tools to read; will require sophistication to build tools. See also JPEG.
Self-documentation

Limited. JFIF defines itself with image dimensions and unit of measurement. Version 1.02 also defines thumbnail dimensions and unit of measurement.

External dependencies None.
Technical protection considerations None.

Quality and functionality factors Explanation of format description terms

Still Image
Normal rendering All versions have wide support. All versions are compatible with each other.
Clarity (high image resolution)

See JPEG_DCT_BL and JPEG_DCT_EXT.

Color maintenance Version 1.02 specification states, “the color space to be used is YCbCr as defined by ITU-R BT.601 (256 levels). The RGB components calculated by linear conversion from YCbCr shall not be gamma corrected (gamma = 1.0). If only one component is used, that component shall be Y.APP0 marker used to identify JPEG JFIF”. The specification further states that this applies to all versions of JFIF.
Support for vector graphics, including graphic effects and typography No support for vector graphics.
Support for multispectral bands No support for multispectral bands.
Functionality beyond normal rendering JFIF 1.02 can support thumbnails. See JFIF, JPEG File Interchange Format, Version 1.02. Earlier versions did not support thumbnails.

File type signifiers and format identifiers Explanation of format description terms

Tag Value Note
Filename extension jpg
jpeg
jpe
jif
jfif
jfi
See File Extension Source. jpeg and jpg are the most common file extensions used.
Filename extension jls
For JPEG-LS files, according to ISO/IEC 14495-1 and PRONOM (see PUID: fmt/150).
Internet Media Type image/jpeg
From the IANA Media Types registry. See also RFC 2046.
Internet Media Type image/jpg
From the IANA Media Types registry. See also RFC 2046.
Magic numbers Hex: FF D8 FF E0 xx xx 4A 46 49 46 00
ASCII: ÿØÿè..JFIF.

JFIF magic numbers follow the JPEG “Start of Image” (SOI) values “0xFFD8” with a JFIF application marker “APPO” (“0xFFEO” in hex) followed by the Length field and the JFIF byte identifier “0x4A46494600”. There is no formal header, these two sets of JGED and JFIF markers in combination act as a signature file header.

For more information, see “JPEG File Interchange Format File Format Summary” taken from the Encyclopedia of Graphics File Formats, 2nd Edition.

Other NF00641
See NARA File Format Preservation Plan ID.
Pronom PUID fmt/42

JPEG File Interchange Format 1.00. See https://www.nationalarchives.gov.uk/pronom/fmt/42

Pronom PUID fmt/43

JPEG File Interchange Format 1.01. See https://www.nationalarchives.gov.uk/pronom/fmt/43

Pronom PUID See related format.  See also JPEG File Interchange Format, Version 1.02.
Wikidata Title ID Q26329975
See https://www.wikidata.org/wiki/Q26329975, JPEG File Interchange Format (JFIF). Group entry for all versions.
Wikidata Title ID Q26329648
See https://www.wikidata.org/wiki/Q26329648, JPEG File Interchange Format (JFIF) version 1.00.
Wikidata Title ID Q26329502
See https://www.wikidata.org/wiki/Q26329502, JPEG File Interchange Format (JFIF) version 1.01.
Wikidata Title ID See related format.  See also JPEG File Interchange Format, Version 1.02.

Notes Explanation of format description terms

General

The JPEG bitstream stores 16-bit word values in big-endian format. JPEG data in general is stored as a stream of blocks, and each block is identified by a marker value. The first two bytes of every JPEG stream are the Start Of Image (SOI) marker values FFh D8h. In a JFIF-compliant file there is a JFIF APP0 (Application) marker, immediately following the SOI, which consists of the marker code values FFh E0h and the characters JFIF in the marker data, as described in the next section. In addition to the JFIF marker segment, there may be one or more optional JFIF extension marker segments, followed by the actual image data. For more, see JFIF, JPEG File Interchange Format, Version 1.02 and JPEG Image Encoding Family.

History

JFIF was developed by C-Cube Microsystems and Independent JPEG group. The creation is credited to Eric Hamilton at C-Cube Microsystems. After its creation, JFIF was placed in the public domain under the maintenance of Independent JPEG Group.

JFIF Version 1.00 was first released in 1991 among a small group of industry representatives. The first public release was Version 1.01 in 1992.

This format was initially released in 1991. Version 1.00 was shared among a small group of industry representatives during the development and public release of Version 1.01 in 1992. Version 1.02 was released shortly after and is “considered the de-facto standard”. All versions are backwards compatible.

According to Ecma TR-98, the differences between versions is relatively minor: Shortly after publication of v1.00, "the group came to the conclusion that the spatial sampling relationship of components specified in JFIF 1.0 was not ideal since it followed digital video conventions rather than those used in common computer formats such as Postscript and QuickTime. They chose to publish another version, JFIF 1.01, which changed that part of the specification to follow the computer format convention. This was deemed to be a minor change since JFIF 1.0 had been circulated for only a short while and decoders which ignored the version number would still render similar images. The Independent JPEG Group (IJG) adopted JFIF version 1.01 for use in its public domain software, which eventually led to millions of images being published in this format. Later in 1992, user feedback led to the final version of JFIF, version 1.02, which supported additional thumbnail formats – most importantly including thumbnails stored in compressed format.


Format specifications Explanation of format description terms


Useful references

URLs

Books, articles, etc.

Last Updated: 11/20/2023