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* Camera settings: This includes static information such as the camera model and make, and information that varies with each image such as orientation (rotation), [[aperture]], [[shutter speed]], [[focal length]], [[metering mode]], and [[ISO speed]] information
* Image metrics: Pixel dimensions, resolution, colorspace, and filesize
* Date and time information, digital cameras will record the current date and time and save this in the metadata
* Location information
* A [[thumbnail]] for previewing the picture on the camera's LCD screen, in file managers, or in photo manipulation software
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{{Expand section|with=changes|date=August 2020}}
The [[Japan Electronic Industries Development Association]] (JEIDA) produced the initial definition of Exif. Version 2.1 of the specification is dated 12
{| class="wikitable"
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|1.0
|October 1995
|Removed dependencies to io package
|-
|1.1
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|2.0
|November 1997
|License change to MIT license
|-
|2.1
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|2.2
|April 2002
|Added [[High Efficiency Image File Format|HEIC]] support
|-
|2.21
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Exif data are embedded within the image file itself. While many recent [[Graphics software|image manipulation programs]] recognize and preserve Exif data when writing to a modified image, this is not the case for most older programs. Many image gallery programs also recognise Exif data and optionally display it alongside the images.
Software libraries, such as libexif<ref>{{cite web | url=https://libexif.github.io/ | title=The libexif C EXIF library | access-date=2022-07-06 }}</ref> for [[C (programming language)|C]] and Adobe XMP Toolkit<ref>{{cite web | url=https://www.adobe.com/devnet/xmp.html | title=Adobe XMP Toolkit SDK | publisher= Adobe Inc. }}</ref> or Exiv2<ref>{{cite web | url=http://www.exiv2.org/ | title=Exiv2 Image Metadata Library | publisher=Andreas Huggel | access-date=2009-02-12 | archive-date=2012-02-12 | archive-url=https://web.archive.org/web/20120212032622/http://www.exiv2.org/ | url-status=dead }}</ref> for [[C++]], Metadata Extractor<ref>{{cite web | url=http://www.drewnoakes.com/code/exif/ | title=Metadata Extractor | publisher=Drew Noakes | access-date=2011-02-18 | archive-date=2007-09-27 | archive-url=https://web.archive.org/web/20070927201245/http://www.drewnoakes.com/code/exif/ | url-status=dead }}</ref> for [[Java (programming language)|Java]], [[Python Imaging Library|PIL/Pillow]] for [[Python (programming language)|Python]], [[LEADTOOLS]] or [[ExifTool]]<ref>{{cite web | url=http://owl.phy.queensu.ca/~phil/exiftool/ | title=Image::ExifTool Perl library | publisher=Phil Harvey | access-date=2009-02-12}}</ref> for [[Perl]], parse Exif data from files and read/write Exif tag values.
==Problems==
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The Exif format has a number of drawbacks, mostly relating to its use of legacy file structures.
* The derivation of Exif from the TIFF file structure using offset pointers in the files means that data can be spread anywhere within a file, which means that software is likely to corrupt any pointers or corresponding data that it
* The standard defines a MakerNote tag, which allows camera manufacturers to place any custom format metadata in the file. This is used increasingly by camera manufacturers to store camera settings not listed in the Exif standard, such as shooting modes, post-processing settings, serial number, focusing modes, etc. As the tag contents are proprietary and manufacturer-specific, it can be difficult to retrieve this information from an image or to properly preserve it when rewriting an image. Manufacturers can encrypt portions of the information; for example, some Nikon cameras encrypt the detailed lens data in the MakerNote data.<ref>{{cite web | title=Nikon Tags: Nikon LensData01 Tags | url=http://owl.phy.queensu.ca/~phil/exiftool/TagNames/Nikon.html#LensData01 | publisher=Phil Harvey | date=2008-01-25 | access-date=2008-01-28}}</ref>
* Exif is very often used in images created by scanners, but the standard makes no provisions for any scanner-specific information.{{citation needed|date=November 2014}}
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Since the Exif tag contains metadata about the photo, it can pose a privacy problem. For example, a photo taken with a [[GPS]]-enabled camera can reveal the exact location and time it was taken, and the unique ID number of the device - this is all done by default - often without the user's knowledge. Many users may be unaware that their photos are tagged by default in this manner, or that specialist software may be required to remove the Exif tag before publishing. For example, a [[whistleblower]], journalist or [[political dissident]] relying on the protection of anonymity to allow them to report [[Misfeasance|malfeasance]] by a corporate entity, criminal, or government may therefore find their safety compromised by this default data collection.
In December 2012, anti-virus businessman [[John McAfee]] was arrested in [[Guatemala]] while fleeing from alleged persecution<ref>{{cite web|url=http://www.cnn.com/2012/12/07/world/americas/guatemala-mcafee-asylum-rejected/index.html |title=McAfee wins stay of deportation from Guatemala |date=7 December 2012 |publisher=
According to documents leaked by [[Edward Snowden]], the [[NSA]] is targeting Exif information under the [[XKeyscore]] program.<ref name =Guardian2>{{cite news| author = Staff | title=XKeyscore Presentation from 2008 – Read in Full – Training Materials for the XKeyscore Program Detail How Analysts Can Use It and Other Systems to Mine Enormous Agency Databases and Develop Intelligence from the Web – Revealed: NSA Program That Collects 'Nearly Everything a User Does on the Internet'|url=https://www.theguardian.com/world/interactive/2013/jul/31/nsa-xkeyscore-program-full-presentation|access-date= August 6, 2013|newspaper= [[The Guardian]] |date= July 31, 2013}}</ref>
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===Example===
[[File:DigiKam EXIF information screenshot.png|thumb|right|[[DigiKam]] screenshot showing Exif data]]
The following table shows Exif metadata for a photo made with a typical digital camera.
{| class="wikitable" style="margin:auto;"
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|Orientation (rotation)
|top-left [8 possible values<ref>{{cite web |url=
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|Software
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