ITU-R BT.1886

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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 standardized by ITU in March 2011. It is used for Rec. 709 (HD-TV) and Rec. 2020 (UHD-TV).[1][2]

Definition[edit]

BT.1886 EOTF is as follows:[1]

where

  • is the screen luminance, in cd/m2.
  • is the input video signal level, in the range .
  • is the exponent of the power function and equal to 2.4
  • is the variable for user gain (legacy “contrast” control)
  • is the variable for user black level lift (legacy “brightness” control)
  • is the screen luminance for white, in cd/m2.
  • is the screen luminance for black, in cd/m2.

According to ITU, for a better match, can be set to 0.1 for moderate black level settings (e.g. 0.1 cd/m2) or to 0 for lower black levels (e.g. 0.01 cd/m2).[1]

An alternative EOTF has also been provided by ITU for the cases a more precise match of CRT characteristics is required.[1]

See also[edit]

References[edit]

  1. ^ a b c d "BT.1886 : Reference electro-optical transfer function for flat panel displays used in HDTV studio production". www.itu.int. Retrieved 2021-11-07.{{cite web}}: CS1 maint: url-status (link)
  2. ^ "BT.2020 : Parameter values for ultra-high definition television systems for production and international programme exchange". www.itu.int. Retrieved 2021-11-07.{{cite web}}: CS1 maint: url-status (link)