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Exchangeable image file format (officially Exif, according to JEIDA/JEITA/CIPA specifications) is a standard that specifies formats for
image An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimensio ...
s,
sound In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by ...
, and ancillary tags used by
digital camera A digital camera is a camera that captures photographs in digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film. Digital cameras are now widely incorporated into mobile devices ...
s (including
smartphone A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whi ...
s), scanners and other systems handling image and sound files recorded by digital cameras. The specification uses the following existing encoding formats with the addition of specific
metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...
tags:
JPEG JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...
lossy coding for compressed image files,
TIFF Tag Image File Format, abbreviated TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing, word process ...
Rev. 6.0 ( RGB or YCbCr) for uncompressed image files, and
RIFF A riff is a repeated chord progression or refrain in music (also known as an ostinato figure in classical music); it is a pattern, or melody, often played by the rhythm section instruments or solo instrument, that forms the basis or acc ...
WAV for audio files (linear
PCM Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. In a PCM stream, the am ...
or ITU-T
G.711 G.711 is a narrowband audio codec originally designed for use in telephony that provides toll-quality audio at 64 kbit/s. G.711 passes audio signals in the range of 300–3400 Hz and samples them at the rate of 8,000 samples per second ...
μ-law PCM for uncompressed audio data, and IMA-
ADPCM Adaptive differential pulse-code modulation (ADPCM) is a variant of differential pulse-code modulation (DPCM) that varies the size of the quantization step, to allow further reduction of the required data bandwidth for a given signal-to-noise ratio ...
for compressed audio data). It does not support
JPEG 2000 JPEG 2000 (JP2) is an image compression standard and coding system. It was developed from 1997 to 2000 by a Joint Photographic Experts Group committee chaired by Touradj Ebrahimi (later the JPEG president), with the intention of superseding the ...
or
GIF The Graphics Interchange Format (GIF; or , see pronunciation) is a bitmap image format that was developed by a team at the online services provider CompuServe led by American computer scientist Steve Wilhite and released on 15 June 1987. ...
encoded images. This standard consists of the Exif image file specification and the Exif audio file specification.


Background

Exif is supported by almost all camera manufacturers. The metadata tags defined in the Exif standard cover a broad spectrum: * 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 In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...
,
shutter speed In photography, shutter speed or exposure time is the length of time that the film or digital sensor inside the camera is exposed to light (that is, when the camera's shutter (photography), shutter is open) when taking a photograph. The am ...
,
focal length The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative foca ...
,
metering mode In photography, the metering mode refers to the way in which a camera determines exposure. Cameras generally allow the user to select between ''spot'', ''center-weighted average'', or ''multi-zone'' metering modes. The different metering modes all ...
, and
ISO speed Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system. A closely related ISO system is used to describe the relations ...
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 Thumbnails are reduced-size versions of pictures or videos, used to help in recognizing and organizing them, serving the same role for images as a normal text index does for words. In the age of digital images, visual search engines and image ...
for previewing the picture on the camera's LCD screen, in file managers, or in photo manipulation software. * Descriptions * Copyright information.


Version history

The
Japan Electronic Industries Development Association The (Formerly ) was an industry research, development, and standards body for electronics in Japan. It was merged with EIAJ to form JEITA on November 1, 2000. JEIDA was similar to SEMATECH of the US, ECMA of Europe. JEIDA developed a number o ...
(JEIDA) produced the initial definition of Exif. Version 2.1 of the specification is dated 12 June 1998.
JEITA The is a Japanese trade organization for the electronics and IT industries. It was formed in 2000 from two earlier organizations, the Electronic Industries Association of Japan and the Japan Electronic Industries Development Association. Histor ...
established Exif version 2.2 (a.k.a. "Exif Print"), dated 20 February 2002 and released in April 2002. Version 2.21 (with
Adobe RGB The Adobe RGB (1998) color space or opRGB is a color space developed by Adobe Systems, Inc. in 1998. It was designed to encompass most of the colors achievable on CMYK color printers, but by using RGB primary colors on a device such as a compu ...
support) is dated 11 July 2003, but was released in September 2003 following the release of DCF 2.0. The latest version 2.3 was released on 26 April 2010, and revised to 2.31 in July 2013 and revised to 2.32 on 17 May 2019, was jointly formulated by
JEITA The is a Japanese trade organization for the electronics and IT industries. It was formed in 2000 from two earlier organizations, the Electronic Industries Association of Japan and the Japan Electronic Industries Development Association. Histor ...
and CIPA.


Technical

The Exif tag structure is borrowed from TIFF files. On several image specific properties, there is a large overlap between the tags defined in the
TIFF Tag Image File Format, abbreviated TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. TIFF is widely supported by scanning, faxing, word process ...
, Exif, TIFF/EP, and DCF standards. For descriptive metadata, there is an overlap between Exif,
IPTC Information Interchange Model The Information Interchange Model (IIM) is a file structure and set of metadata attributes that can be applied to text, images and other media types. It was developed in the early 1990s by the International Press Telecommunications Council (IPTC) t ...
and XMP info, which also can be embedded in a JPEG file. The Metadata Working Group has guidelines on mapping tags between these standards. When Exif is employed for
JPEG JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...
files, the Exif data are stored in one of JPEG's defined utility ''Application Segments'', the APP1 (segment marker 0xFFE1), which in effect holds an entire TIFF file within. When Exif is employed in TIFF files (also when used as "an embedded TIFF file" mentioned earlier), the TIFF Private Tag 0x8769 defines a sub-Image File Directory (IFD) that holds the Exif specified TIFF Tags. In addition, Exif also defines a
Global Positioning System The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...
sub-IFD using the TIFF Private Tag 0x8825, holding location information, and an "Interoperability IFD" specified within the Exif sub-IFD, using the Exif tag 0xA005. Formats specified in Exif standard are defined as folder structures that are based on Exif-JPEG and recording formats for memory. When these formats are used as Exif/DCF files together with the DCF specification (for better interoperability among devices of different types), their scope shall cover devices, recording media, and application software that handle them.


Geolocation

The Exif format has standard tags for location information. , many cameras and mobile phones have a built-in GPS receiver that stores the location information in the Exif header when a picture is taken. Some other cameras have a separate GPS receiver that fits into the flash connector or
hot shoe Canon EOS 350D Hot shoe Proprietary hot shoe used by Minolta and older Sony cameras (Konica Minolta Maxxum 7D">Sony.html" ;"title="Minolta and older Sony">Minolta and older Sony cameras (Konica Minolta Maxxum 7D) A hot shoe is a mounting poin ...
. Recorded GPS data can also be added to any digital photograph on a computer, either by correlating the time stamps of the photographs with a GPS record from a hand-held GPS receiver or manually by using a map or mapping software. Some cameras can be paired with cellphones to provide the geolocation. The process of adding geographic information to a photograph is known as
geotagging Geotagging, or GeoTagging, is the process of adding geographical identification metadata to various media such as a geotagged photograph or video, websites, SMS messages, QR Codes or RSS feeds and is a form of geospatial metadata. This data u ...
. Photo-sharing communities like
Panoramio Panoramio was a geo-tagging, geo-located tagging, photo sharing Mashup (web application hybrid), mashup active between 2005 and 2016. Photos uploaded to the site were accessible as a layer in Google Earth and Google Maps. The site's goal was to a ...
, locr or
Flickr Flickr ( ; ) is an American image hosting and video hosting service, as well as an online community, founded in Canada and headquartered in the United States. It was created by Ludicorp in 2004 and was a popular way for amateur and professional ...
equally allow their users to upload geocoded pictures or to add geolocation information online.


Program support

Exif data are embedded within the image file itself. While many recent 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 for C and Adobe XMP Toolkit or Exiv2 for
C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...
, Metadata Extractor for
Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...
, PIL/Pillow for
Python Python may refer to: Snakes * Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia ** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia * Python (mythology), a mythical serpent Computing * Python (pro ...
, LEADTOOLS or
ExifTool ExifTool is a free and open-source software program for reading, writing, and manipulating image, audio, video, and PDF metadata. It is platform independent, available as both a Perl library (Image::ExifTool) and command-line application. Exi ...
for
Perl Perl is a family of two high-level, general-purpose, interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it also referred to its redesigned "sister language", Perl 6, before the latter's name was offici ...
, parse Exif data from files and read/write Exif tag values.


Problems


Technical

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 doesn't decode/encode. For this reason most image editors damage or remove the Exif metadata to some extent upon saving. * 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. * Exif is very often used in images created by scanners, but the standard makes no provisions for any scanner-specific information. * Photo manipulation software sometimes fails to update the embedded thumbnail after an editing operation, possibly causing the user to inadvertently publish compromising information. For example, someone might blank out a licence registration plate of a car (for privacy concerns), only to have the thumbnail not so updated, meaning the information is still visible. * Exif metadata are restricted in size to 64 kB in JPEG images because according to the specification this information must be contained within a single JPEG APP1 segment. Although the FlashPix extensions allow information to span multiple JPEG APP2 segments, these extensions are not commonly used. This has prompted some camera manufacturers to develop non-standard techniques for storing the large preview images used by some digital cameras for LCD review. These non-standard extensions are commonly lost if a user re-saves the image using image editor software, possibly rendering the image incompatible with the original camera that created it. (In 2009, CIPA released the Multi Picture Object specification which addresses this deficiency and provides a standard way to store large previews in JPEG images.) * There is no way to record time-zone information along with the time, thus rendering the stored time ambiguous. However, time-zone information has been introduced recently by Exif version 2.31 (July 2016). Related tags are: "OffsetTime", "OffsetTimeOriginal" and "OffsetTimeDigitized". * There is no standard field to record readouts of a camera's
accelerometers An accelerometer is a tool that measures proper acceleration. Proper acceleration is the acceleration (the rate of change of velocity) of a body in its own instantaneous rest frame; this is different from coordinate acceleration, which is accele ...
or
inertial navigation system An inertial navigation system (INS) is a navigation device that uses motion sensors (accelerometers), rotation sensors ( gyroscopes) and a computer to continuously calculate by dead reckoning the position, the orientation, and the velocity (dire ...
. Such data could help to establish the relationship between the image sensor's XYZ coordinate system and the gravity
vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...
(i.e., which way is down in this image). It could also establish relative camera positions or orientations in a sequence of photos. Some software records this information using the GPSImgDirection tag along with custom GPSPitch and GPSRoll tags. * The XResolution and YResolution tags provide the number of pixels per length unit for the width and height of the image, respectively. (The length unit itself is specified by the tag ResolutionUnit.) By default, these tags in combination are set to 72
pixels per inch In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device. In most digital display devices, pixels are the smal ...
(ppi). These tags were inherited from the TIFF 6.0 standard and are required even though for images produced by digital cameras, image resolution values such as ppi are meaningless.


Privacy and security

Since the Exif tag contains metadata about the photo, it can pose a privacy problem. For example, a photo taken with a
GPS The Global Positioning System (GPS), originally Navstar GPS, is a Radionavigation-satellite service, satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of t ...
-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 A whistleblower (also written as whistle-blower or whistle blower) is a person, often an employee, who reveals information about activity within a private or public organization that is deemed illegal, immoral, illicit, unsafe or fraudulent. Whi ...
, journalist or
political dissident A dissident is a person who actively challenges an established political or religious system, doctrine, belief, policy, or institution. In a religious context, the word has been used since the 18th century, and in the political sense since the 20th ...
relying on the protection of anonymity to allow them to report
malfeasance Misfeasance, nonfeasance, and malfeasance are types of failure to discharge public obligations existing by common law, custom, or statute. The Carta de Logu caused Eleanor of Arborea to be remembered as one of the first lawmakers to set up the ...
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 John David McAfee ( ; 18 September 1945 – 23 June 2021) was a British-American computer programmer, businessman, and two-time presidential candidate who unsuccessfully sought the Libertarian Party nomination for president of the United States ...
was arrested in
Guatemala Guatemala ( ; ), officially the Republic of Guatemala ( es, República de Guatemala, links=no), is a country in Central America. It is bordered to the north and west by Mexico; to the northeast by Belize and the Caribbean; to the east by H ...
while fleeing from alleged persecution in neighboring
Belize Belize (; bzj, Bileez) is a Caribbean and Central American country on the northeastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a wate ...
. ''
Vice A vice is a practice, behaviour, or habit generally considered immoral, sinful, criminal, rude, taboo, depraved, degrading, deviant or perverted in the associated society. In more minor usage, vice can refer to a fault, a negative character tra ...
'' magazine had published an exclusive interview on their website with McAfee "on the run" that included a photo of McAfee with a ''Vice'' reporter taken with a phone that had geotagged the image. The photo's metadata included GPS coordinates locating McAfee in Guatemala, and he was captured two days later. McAfee later claimed to have edited the Exif data from his phone to provide a false location. According to documents leaked by
Edward Snowden Edward Joseph Snowden (born June 21, 1983) is an American and naturalized Russian former computer intelligence consultant who leaked highly classified information from the National Security Agency (NSA) in 2013, when he was an employee and su ...
, the
NSA The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence (DNI). The NSA is responsible for global monitoring, collecti ...
is targeting Exif information under the
XKeyscore XKeyscore (XKEYSCORE or XKS) is a secret computer system used by the United States National Security Agency (NSA) for searching and analyzing global Internet data, which it collects in real time. The NSA has shared XKeyscore with other intellige ...
program. The privacy problem of Exif data can be avoided by removing the Exif data using a
metadata removal tool Metadata removal tool or metadata scrubber is a type of privacy software built to protect the privacy of its users by removing potentially privacy-compromising metadata from files before they are shared with others, e.g., by sending them as e-mail ...
.


Related standards

Metadata Working Group The Metadata Working Group was formed in 2006 by Adobe Systems, Apple, Canon, Microsoft and Nokia. Sony joined later in 2008. The focus of the group is to advance the interoperability of metadata stored in digital media. Its specificationGuideli ...
was formed by a consortium of companies in 2006 (according to their web page) or 2007 (as stated in their own press release). Version 2.0 of the specification was released in November 2010, giving recommendations concerning the use of Exif,
IPTC The International Press Telecommunications Council (IPTC), based in London, United Kingdom, is a consortium of the world's major news agencies, other news providers and news industry vendors and acts as the global standards body of the news media. ...
and XMP metadata in images. Extensible Metadata Platform (XMP) is an
ISO standard The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Art ...
, originally created by
Adobe Systems Inc. Adobe Inc. ( ), originally called Adobe Systems Incorporated, is an American Multinational corporation, multinational software, computer software company Delaware General Corporation Law, incorporated in Delaware and headquartered in San Jose ...
, for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets.
IPTC The International Press Telecommunications Council (IPTC), based in London, United Kingdom, is a consortium of the world's major news agencies, other news providers and news industry vendors and acts as the global standards body of the news media. ...
was developed in the early 1990s by the
International Press Telecommunications Council The International Press Telecommunications Council (IPTC), based in London, United Kingdom, is a consortium of the world's major news agencies, other news providers and news industry vendors and acts as the global standards body of the news media. ...
(IPTC) to expedite the international exchange of news among newspapers and news agencies.


Exif Fields

Not all devices use every available metadata field in the Exif standard.


Example

The following table shows Exif metadata for a photo made with a typical digital camera. Notice that authorship and copyright information is generally not provided in the camera's output, so it must be filled in during later stages of processing. Some programs, such as Canon's
Digital Photo Professional Digital Photo Professional (DPP) is the software that Canon ships with its digital SLR (and some of its compacts, e.g. the Canon PowerShot S90) cameras for editing and asset management of its Canon raw (.CR2) files. It can also work with the older ...
, allow the name of the owner to be added to the camera itself.


Time Tags

In addition to the basic date and time tags (DateTime, DateTimeOriginal, and DateTimeDigitized), there are three corresponding "subsecond" tags: SubsecTime, SubsecTimeOriginal, and SubsecTimeDigitized. The SubsecTime tag is defined in version 2.3 as "a tag used to record fractions of seconds for the DateTime tag;" the SubsecTimeOriginal and SubsecTimeDigitized fields are defined similarly. The subsecond tags are of variable length, meaning manufacturers may choose the number of ASCII-encoded decimal digits to place in these tags. For DateTime = 2000:01:01 00:00:00, the actual time with various subsecond values would be: * SubsecTime = 2: 2000:01:01 00:00:00.2 * SubsecTime = 23: 2000:01:01 00:00:00.23 * SubsecTime = 234: 2000:01:01 00:00:00.234 * SubsecTime = 2345: 2000:01:01 00:00:00.2345 The standard does not specify which particular event during the "taking" of a picture the time tags should describe. The standard is, in fact, ambiguous. The DateTimeOriginal tag is defined as "The date and time when the original image data was generated." For an exposure—say, 30 seconds—longer than the granularity of the timestamp (one second for the DateTimeOriginal tag), the tag's time could correspond to the beginning of the exposure, the end of the exposure, or some other time. This confusion is exacerbated for the subsecond tags, where the granularity (down to 1/10000th of a second in the examples in the standard) is shorter than many common exposure durations. As noted above, tags to specify the previously-missing timezone information were added in Exif version 2.31. These are "OffsetTime", "OffsetTimeOriginal" and "OffsetTimeDigitized". They are formatted as seven ASCII characters (including the null terminator) denoting the hours and minutes of the offset, like +01:00 or -01:00. The offset is "from UTC (the time difference from Universal Coordinated Time including daylight saving time) of the time of" the matching tag.


FlashPix extensions

The Exif specification also includes a description of FPXR (FlashPix-ready) information, which may be stored in APP2 of
JPEG JPEG ( ) is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and imag ...
images using a structure similar to that of a
FlashPix FlashPix is a bitmapped computer graphics file format where the image is saved in more than one resolution. Its design anticipated that when an HTTP request is sent for the file by a browser plugin implementing the format, only the image compatibl ...
file. These FlashPix extensions allow meta-information to be preserved when converting between FPXR JPEG images and FlashPix images. FPXR information may be found in images from some models of digital cameras by
Kodak The Eastman Kodak Company (referred to simply as Kodak ) is an American public company that produces various products related to its historic basis in analogue photography. The company is headquartered in Rochester, New York, and is incorpor ...
and
Hewlett-Packard The Hewlett-Packard Company, commonly shortened to Hewlett-Packard ( ) or HP, was an American multinational information technology company headquartered in Palo Alto, California. HP developed and provided a wide variety of hardware components ...
. Below is an example of the FPXR information found in a JPEG image from a
Kodak EasyShare V570 The Kodak EasyShare V570 was a 5-megapixel digital camera manufactured by Eastman Kodak. Announced on January 2, 2006, it was an upper-end model in the consumer price range, advertised at $400 in the United States in January 2006. It had an innov ...
digital camera:


Exif audio files

The Exif specification describes the
RIFF A riff is a repeated chord progression or refrain in music (also known as an ostinato figure in classical music); it is a pattern, or melody, often played by the rhythm section instruments or solo instrument, that forms the basis or acc ...
file format used for WAV audio files and defines a number of tags for storing meta-information such as artist, copyright, creation date, and more in these files. The following table gives an example of Exif information found in a WAV file written by the
Pentax Optio WP The Pentax Optio series is a line of consumer digital cameras manufactured by Pentax, Pentax Corporation. It consists mostly of point-and-shoot cameras, and encompasses the bulk of Pentax's lower-end camera models. These products typically rang ...
digital camera:


MakerNote data

The "MakerNote" tag contains image information normally in a proprietary binary format. Some of these manufacturer-specific formats have been decoded: * OZHiker (not updated since 2008): Agfa, Canon, Casio, Epson, Fujifilm, Konica/Minolta, Kyocera/Contax, Nikon, Olympus, Panasonic, Pentax/Asahi, Ricoh, Sony * Kamisaka (not updated since 2007): Canon, Casio, FujiFilm, ISL, KDDI, Konica/Minolta, Mamiya, Nikon, Panasonic, Pentax, Ricoh, Sigma, Sony, WWL * X3F Info: Sigma/Foveon *
ExifTool ExifTool is a free and open-source software program for reading, writing, and manipulating image, audio, video, and PDF metadata. It is platform independent, available as both a Perl library (Image::ExifTool) and command-line application. Exi ...
: Canon, Casio, FujiFilm, GE, HP, JVC/Victor, Kodak, Leaf, Minolta/Konica-Minolta, Nikon, Olympus/Epson, Panasonic/Leica, Pentax/Asahi, Reconyx, Ricoh, Samsung, Sanyo, Sigma/Foveon, Sony, etc. * Olypedia: Olympus The proprietary formats used by many manufacturers break if the MakerNote tag data is moved (i.e. by inserting or editing a tag that precedes it). The reason to edit to the Exif data could be as simple as to add copyright information, an Exif comment, etc. There are two solutions for this problem: * When the Exif data is saved, the MakerNote data is stored at the same place as before. * A special offset tag is added. This tag contains the information by how many bytes the MakerNote data was moved in comparison to the original index. Microsoft has implemented the last solution in Windows 10: In the Windows explorer you can change the Exif data of an image file by the properties window. Here the tab sheet "Details" contains some Exif data like title, subject, comments etc. and these Exif data can also be changed and stored. When the image file is saved the tag "OffsetSchema" (tag ID = 0xea1d) is added and this tag contains a signed 32 bit number. With this number the original index of "MakerNote" can be restored: Original index of "MakerNote" = Current index of "MakerNote" - Value of tag "OffsetSchema" But the tag "OffsetSchema" was defined by Microsoft and it is not part of the official Exif standard. In some cases, camera vendors also store important information only in proprietary makernote fields, instead of using available Exif standard tags. An example for this is Nikon's ISO speed settings tag.


See also

*
Additive System of Photographic Exposure APEX stands for Additive System of Photographic Exposure, which was proposed in the 1960 ASA standard for monochrome film speed, ASA PH2.5-1960, as a means of simplifying exposure computation. Exposure equation Until the late 1960s, cameras did ...
(APEX) *
Comparison of image viewers This article presents a comparison of image viewers and image organizers which can be used for image viewing. Functionality overview and licensing Supported file formats Commonly used vendor-independent formats Camera raw formats Suppor ...
(Exif view/edit functions) *
Design rule for Camera File system Design rule for Camera File system (DCF) is a JEITA specification (number CP-3461) which defines a file system for digital cameras, including the directory structure, file naming method, character set, file format, and metadata format. It is cur ...
(DCF) *
Digital photography Digital photography uses cameras containing arrays of electronic photodetectors interfaced to an analog-to-digital converter (ADC) to produce images focused by a lens, as opposed to an exposure on photographic film. The digitized image is sto ...
* eXtensible Metadata Platform (XMP) *
Geocoded photo A geotagged photograph is a photograph which is associated with a geographic position by geotagging. Usually this is done by assigning at least a latitude and longitude to the image, and optionally elevation, compass bearing and other fields may ...
*
Image file formats An Image file format is a file format for a digital image. There are many formats that can be used, such as JPEG, PNG, and GIF. Most formats up until 2022 were for storing 2D images, not 3D ones. The data stored in an image file format may be c ...
*
IPTC Information Interchange Model The Information Interchange Model (IIM) is a file structure and set of metadata attributes that can be applied to text, images and other media types. It was developed in the early 1990s by the International Press Telecommunications Council (IPTC) t ...
*
JPEG File Interchange Format The JPEG File Interchange Format (JFIF) is an image file format standard published as ITU-T Recommendation T.871 and ISO/IEC 10918-5. It defines supplementary specifications for the container format that contains the image data encoded with the JP ...
*
Metadata Working Group The Metadata Working Group was formed in 2006 by Adobe Systems, Apple, Canon, Microsoft and Nokia. Sony joined later in 2008. The focus of the group is to advance the interoperability of metadata stored in digital media. Its specificationGuideli ...
*
Tag Image File Format / Electronic Photography Tag Image File Format/Electronic Photography (TIFF/EP) is a digital image file format standard – ISO 12234-2, titled "Electronic still-picture imaging – Removable memory – Part 2: TIFF/EP image data format". This is different from the ...
(TIFF/EP) *
JEIDA memory card The JEIDA memory card standard is a popular memory card standard at the beginning of memory cards appearing on portable computers. JEIDA cards could be used to expand system memory or as a solid-state storage drive. History Before the advent ...


References


External links


CIPA Standards - Camera & Imaging Products Association

Exif standard version 2.32 *New

Exif standard version 2.3
* Exif standard version 2.2 a


Exif Exchangeable Image File Format, Version 2.2

Exif standard version 2.1



Metadata working group


{{Graphics file formats Digital photography Graphics file formats JPEG Metadata