http://fileformats.archiveteam.org/api.php?action=feedcontributions&feedformat=atom&user=Kunch 2026-05-04T20:55:03Z User contributions MediaWiki 1.19.2 http://fileformats.archiveteam.org/wiki/JFIF 2020-03-02T17:01:27Z

<p>Kunch: Changed link to updated &quot;JFIF poster&quot;</p> <hr /> <div>{{FormatInfo<br /> |formattype=electronic<br /> |subcat=Graphics<br /> |extensions={{ext|jpg}}, {{ext|jpeg}}, {{ext|jfif}}, {{ext|jfi}}<br /> |mimetypes={{mimetype|image/jpeg}}<br /> |locfdd={{LoCFDD|fdd000018}}<br /> |pronom={{PRONOM|fmt/42}}, {{PRONOM|fmt/43}}, {{PRONOM|fmt/44}}<br /> |wikidata={{wikidata|Q26329975}}<br /> |released=1991<br /> }}<br /> '''JFIF''' ('''JPEG File Interchange Format''') is a standard that defines a portable subset of the [[JPEG]] file format. Most of the JPEG files in existence conform to JFIF.<br /> <br /> JFIF defines JPEG application segments which serve to identify JFIF files, and to store a small amount of metadata: the pixel density, and a thumbnail image.<br /> <br /> The presence of a JFIF segment implies that:<br /> * If the image has three components, its color format is YCbCr, using a conversion formula given in the specification. If it has one component, its color format is grayscale.<br /> * The image has a particular orientation.<br /> * If the image is subsampled, it uses a particular subsampling position.<br /> <br /> JFIF was developed based on a draft version of the JPEG standard, which is how it can predate JPEG's official 1992 publication date.<br /> <br /> == Disambiguation ==<br /> Don't confuse '''JPEG File Interchange Format''' with '''JPEG Interchange Format'''. The former is '''JFIF'''; the latter means approximately the same thing as [[JPEG]].<br /> <br /> == Identification ==<br /> Valid JFIF files begin with &lt;code&gt;FF D8 FF E0 ?? ?? 'J' 'F' 'I' 'F' 00&lt;/code&gt;. Some technically-invalid files exist in which the JFIF segment has been relocated, and for them this signature will not match.<br /> <br /> == Versions ==<br /> <br /> * The original version (let's call it JFIF 1.00) must have existed in some form, but little seems to be known about it.<br /> <br /> * JFIF 1.01 (1991-12-10) may have changed the subsampling position to ''centered''.<br /> <br /> * JFIF 1.02 (1992-09-01) added an optional JFXX segment, capable of storing a compressed thumbnail image.<br /> <br /> * JFIF 2.xx (~2014): Starting with version 9a, the Independent JPEG Group's software supports &quot;JFIF 2.01&quot; (e.g. using &lt;code&gt;cjpeg -bgycc&lt;/code&gt;), which apparently implies that the image uses &quot;big gamut YCC&quot;. We have not located any specifications for this JFIF version. Note that some buggy JFIF encoders have been known to label a file as version 2.01, when 1.02 was intended.<br /> <br /> == Specifications ==<br /> * JFIF 1.02:<br /> ** [https://www.w3.org/Graphics/JPEG/jfif3.pdf jfif3.pdf]<br /> ** [http://www.textfiles.com/programming/FORMATS/jpegjfif JFIF description (Eric Hamilton, 1992-09-01)]<br /> ** [https://web.archive.org/web/20011026132227/http://www.ijg.org/files/ Archive of www.ijg.org/files/] → jfif.ps.gz, jfif.txt.gz<br /> * Based on JFIF 1.02:<br /> ** [https://www.itu.int/rec/T-REC-T.871/en ITU-T Rec. T.871]<br /> ** [https://www.ecma-international.org/publications/techreports/E-TR-098.htm ECMA TR/98]<br /> ** [https://www.iso.org/standard/54989.html ISO/IEC 10918-5:2013] (Not free to download)<br /> * [https://entropymine.com/archived/jpeg.jfif.doc.1.01.ps.Z JFIF 1.01]<br /> <br /> == Links ==<br /> * [[Wikipedia:JPEG File Interchange Format|Wikipedia article]]<br /> * {{EGFF|jpeg|JPEG File Interchange Format File Format Summary}}, from the [[Encyclopedia of Graphics File Formats]]<br /> * [https://github.com/corkami/pics/blob/master/binary/JPG.png JFIF poster]<br /> <br /> [[Category:JPEG]]</div>

Kunch