This article is about the

transfer functions Transfer may refer to: Arts and media * ''Transfer'' (2010 film), a German science-fiction movie directed by Damir Lukacevic and starring Zana Marjanović * ''Transfer'' (1966 film), a short film * ''Transfer'' (journal), in management studies ...

used in pictures and

videos Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) sy ...

and describing the relationship between electrical signal, scene light and displayed light.

Definition

The opto-electronic transfer function (OETF) is the transfer function having the scene light as input and converting into the picture or video signal as output. This is typically done within a camera. The electro-optical transfer function (EOTF) is the transfer function having the picture or video signal as input and converting it into the linear light output of the display. This is done within the display device. The opto-optical transfer function (OOTF) is the transfer function having the scene light as input and the displayed light as output. The OOTF is the result of the OETF and the EOTF and is usually non- linear.

List of transfer functions

Linear

* Raw formats *Some OETF and EOTF have an initial linear portion followed by a non-linear part (e.g.

sRGB sRGB is a standard RGB (red, green, blue) color space that HP and Microsoft created cooperatively in 1996 to use on monitors, printers, and the World Wide Web. It was subsequently standardized by the International Electrotechnical Commission ( ...

and Rec.709).

Gamma Gamma (uppercase , lowercase ; ''gámma'') is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter re ...

Rec. 601 ITU-R Recommendation BT.601, more commonly known by the abbreviations Rec. 601 or BT.601 (or its former name CCIR 601) is a standard originally issued in 1982 by the CCIR (an organization, which has since been renamed as the Internatio ...

, Rec. 709 and

Rec. 2020 ITU-R Recommendation BT.2020, more commonly known by the abbreviations Rec. 2020 or BT.2020, defines various aspects of ultra-high-definition television (UHDTV) with standard dynamic range (SDR) and wide color gamut (WCG), including picture ...

: The ITU-R recommendations BT.601, BT.709 and BT.2020 describe the reference OETF of respectively SD-TV, HD-TV and UHD-TV. They are identical OETF based on a gamma curve and used for SDR-TV. *

BT.1886 ITU-R BT.1886 is the reference EOTF of SDR-TV. It is a gamma 2.4 transfer function (a power law with a 2.4 exponent) considered as a satisfactory approximation of the response characteristic of CRT to electrical signal. It has been standardi ...

: The ITU-R Recommendation BT.1886 is the reference EOTF of Standard Dynamic Range TV (SDR). *

: sRGB defines a transfer function based on a gamma curve and used for monitors, printers, and the

Web Web most often refers to: * Spider web, a silken structure created by the animal * World Wide Web or the Web, an Internet-based hypertext system Web, WEB, or the Web may also refer to: Computing * WEB, a literate programming system created by ...

. sRGB is standardized as IEC 61966-2-1:1999

Logarithmic Logarithmic can refer to: * Logarithm, a transcendental function in mathematics * Logarithmic scale, the use of the logarithmic function to describe measurements * Logarithmic spiral, * Logarithmic growth * Logarithmic distribution, a discrete pr ...

* S-Log: Developed by Sony for digital cameras in order to increase captured dynamic range *

Canon Log Canon or Canons may refer to: Arts and entertainment * Canon (fiction), the conceptual material accepted as official in a fictional universe by its fan base * Literary canon, an accepted body of works considered as high culture ** Western can ...

: Developed by Canon for digital cameras in order to increase captured dynamic range *Arri Log C: Developed by Arri for digital cameras in order to increase captured dynamic range

HDR

These transfer functions have been developed to allow HDR display: *

Perceptual quantizer The perceptual quantizer (PQ), published by SMPTE as SMPTE ST 2084, is a transfer function that allows for HDR display by replacing the gamma curve used in SDR. It is capable of representing luminance level up to 10000 cd/m2 (nits) and down to ...

: PQ is a transfer function developed by

Dolby Dolby Laboratories, Inc. (often shortened to Dolby Labs and known simply as Dolby) is an American company specializing in audio noise reduction, audio encoding/compression, spatial audio, and HDR imaging. Dolby licenses its technologies to ...

for HDR and allowing a

luminance Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls withi ...

level of up to 10,000 cd/m². It is standardized in Rec. 2100 and also as SMPTE ST 2084. * Hybrid log–gamma: HLG is a transfer function developed by NHK and BBC for HDR and offering some backward compatibility on SDR displays. HLG is a hybrid transfer function in which the lower half of the signal values use a gamma curve and the upper half of the signal values use a logarithmic curve. It is standardized in Rec. 2100.

References

{{Reflist Transfer functions Video Imaging