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Standard-dynamic-range video (SDR video) is a video technology which represents light intensity based on the brightness, contrast and color characteristics and limitations of a cathode ray tube (CRT) display.cite-ref-1-1-0[1] SDR video is able to represent a video or picture's colors with a maximum luminance around 100 cd/m2, a black level around 0.1 cd/m2 and Rec.709 / sRGB color gamut.cite-ref-1-1-1[1]cite-ref-6-2-0[2] It uses the gamma curve as its electro-optical transfer function.cite-ref-1-1-2[1]cite-ref-0-3-0[3]

The first CRT television sets were manufactured in 1934 and the first color CRT television sets were manufactured in 1954.cite-ref-15gp22colorcrt2016-4-0[4]cite-ref-earlytelevisiongallery2016-5-0[5] The term "standard-dynamic-range video" was adopted to distinguish SDR video from high-dynamic-range video (HDR video), a new technology that was developed in the 2010s to overcome SDR's limits.cite-ref-1-1-3[1]cite-ref-6[6]

• Technical details

• Transfer function

• Color gamut

• Dynamic range

• Displaying SDR video on modern displays

• References

• External links

Conventional gamma curves:

• Opto-electronic transfer function (OETF):

• Rec. 601 (analog video signals in SD-TV digital video form)cite-ref-7[7]cite-ref-reporthdr2015smpte-8-0[8]

• Rec. 709 (HD-TV)cite-ref-reporthdr2015smpte-8-1[8]

• Rec. 2020 (UHD-TV)

• sRGB

• Electro-optical transfer function (EOTF):

• ITU-R BT.1886 (SDR-TV)cite-ref-0-3-1[3]

• sRGB (monitors, printers, World Wide Web)cite-ref-orig-pub-9-0[9]

The linear part of the conventional gamma curve was used to limit camera noise in low light video but is no longer needed with high dynamic range (HDR) cameras.cite-ref-reporthdr2015smpte-8-2[8] An example of a conventional gamma curve would be Rec. 601:

E = { 4.500 L L < 0.018 1.099 L 0.45 − − 0.099 L ≥ ≥ 0.018 {\displaystyle E={\begin{cases}4.500L&L<0.018\\1.099L^{0.45}-0.099&L\geq 0.018\end{cases}}}

ITU-R Recommendation BT.1886 describe the reference EOTF of SDR.cite-ref-0-3-2[3] It's a gamma curve representing the response of CRT to video signal.cite-ref-0-3-3[3] It has been published by ITU in 2011.cite-ref-0-3-4[3]

A transfer function that is closer to Weber's law allows for a larger dynamic range, at the same bit depth, than a conventional gamma curve.cite-ref-displayhdr2015bbc-10-0[10] HDR standards such as hybrid log–gamma (HLG) and SMPTE ST 2084 allow for a larger dynamic range by using a different transfer function.cite-ref-displayhdr2015bbc-10-1[10]cite-ref-dolbyvision2016dolby-11-0[11] HLG is compatible with SDR displays.cite-ref-ibcdemo2015ebu-12-0[12]

In some cases the term SDR is also used with a meaning including the standard color gamut (i.e. Rec. 709 / sRGB color primaries).cite-ref-1-1-4[1] HDR uses wide color gamut (WCG) such as Rec. 2020 or DCI-P3 color primaries.cite-ref-1-1-5[1]cite-ref-2-13-0[13]

The dynamic range that can be perceived by the human eye in a single image is around 14 stops.cite-ref-displayhdr2015bbc-10-2[10] SDR video with a conventional gamma curve and a bit depth of 8-bits per sample has a dynamic range of about 6 stops, assuming a luminance quantisation threshold of 5% is used.cite-ref-displayhdr2015bbc-10-3[10] A threshold of 5% is used in the paper (instead of the standard 2% threshold) to allow for the typical display being dimmer than ideal. Professional SDR video with a bit depth of 10-bits per sample has a dynamic range of about 10 stops.cite-ref-displayhdr2015bbc-10-4[10]

While conventional gamma curves are useful for low light and are compatible with CRT displays, they can only represent a limited dynamic range.cite-ref-displayhdr2015bbc-10-5[10]cite-ref-dolbyvision2016dolby-11-1[11] Standards require SDR to be viewed on a display with the same characteristics as a CRT (i.e. 100 nits peak brightness, gamma curve, Rec. 709 color primaries).cite-ref-1-1-6[1]cite-ref-0-3-5[3] However, current displays are often far more capable than CRT's limits.cite-ref-1-1-7[1] On such displays, higher brightness and wider color gamut can be displayed by adjusting and trying to enhance the SDR picture.cite-ref-1-1-8[1] HDR is however required for the creative intents to be preserved.cite-ref-1-1-9[1]

cite-note-1-11. ↑ "HDR (High Dynamic Range) on TVs explained". FlatpanelsHD. Retrieved 2021-04-25.

cite-note-6-22. ↑ "ITU-R Report BT.2390 - High dynamic range television for production and international programme exchange". ITU. Retrieved 2021-04-29.

cite-note-0-33. ↑ "BT.1886 : Reference electro-optical transfer function for flat panel displays used in HDTV studio production". www.itu.int. Retrieved 2021-04-24.

cite-note-15gp22colorcrt2016-44. ↑ "15GP22 Color CRT". Early Television Museum. Retrieved 2016-02-02.

cite-note-earlytelevisiongallery2016-55. ↑ "Early Electronic Television". Early Television Museum. Retrieved 2016-02-02.

cite-note-66. ↑ "CES 2014: Dolby Vision promises a brighter future for TV, Netflix and Xbox Video on board". Expert Reviews. 6 January 2014. Retrieved 2021-04-24.

cite-note-77. ↑ "BT.601: Studio encoding parameters of digital television for standard 4:3 and wide screen 16:9 aspect ratios". ITU.

cite-note-reporthdr2015smpte-88. ↑ "Study Group Report High-Dynamic-Range (HDR) Imaging Ecosystem". Society of Motion Picture and Television Engineers. Retrieved 2016-02-02.

cite-note-orig-pub-99. ↑ citerefmichael-stokesmatthew-andersonsrinivasan-chandrasekarricardo-motta1996Michael Stokes; Matthew Anderson; Srinivasan Chandrasekar; Ricardo Motta (November 5, 1996). "A Standard Default Color Space for the Internet – sRGB, Version 1.10".

cite-note-displayhdr2015bbc-1010. ↑ citereft-borera-cottonT. Borer; A. Cotton. "A "Display Independent" High Dynamic Range Television System" (PDF). BBC. Retrieved 2016-02-02.

cite-note-dolbyvision2016dolby-1111. ↑ "Dolby Vision White Paper" (PDF). Dolby Laboratories. Retrieved 2016-02-02.

cite-note-ibcdemo2015ebu-1212. ↑ "High Dynamic Range" (PDF). European Broadcasting Union. Retrieved 2015-11-01.

cite-note-2-1313. ↑ "BT.2100 : Image parameter values for high dynamic range television for use in production and international programme exchange". www.itu.int. Retrieved 2021-04-25.

• ITU-R Recommendation BT.1886