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Perceptual quantizer
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<p>The perceptual quantizer (PQ), published by <a href="/facts/Society_of_Motion_Picture_and_Television_Engineers/lwCdWynu">SMPTE</a> as SMPTE ST 2084, is a <a href="/facts/Transfer_functions_in_imaging/6MVRUugA">transfer function</a> that allows for <a href="/facts/High-dynamic-range_video/jzRH1mFe">HDR</a> display by replacing the <a href="/facts/Gamma_correction/cApBLTYj">gamma curve</a> used in <a href="/facts/Standard-dynamic-range_video/URDwL3DT">SDR</a>. Its 0–1value range represents luminance levels from 0 to 10,000 <a href="/facts/Candela_per_square_metre/9CaTeynY">cd/m2</a> (nits). It was developed by <a href="/facts/Dolby_Laboratories/0rcH0SmW">Dolby</a> and standardized in 2014 by <a href="/facts/Society_of_Motion_Picture_and_Television_Engineers/lwCdWynu">SMPTE</a> and also in 2016 by <a href="/facts/International_Telecommunication_Union/Yn8UKKkw">ITU</a> in <a href="/facts/Rec._2100/tEI3hkot">Rec. 2100</a>. ITU specifies the use of PQ or <a href="/facts/Hybrid_log%25E2%2580%2593gamma/9oIkzshp">HLG</a> as transfer functions for HDR-TV. PQ is the basis of HDR video formats (such as <a href="/facts/Dolby_Vision/30nFDn7Y">Dolby Vision</a>, <a href="/facts/HDR10/VP97NWpz">HDR10</a> and <a href="/facts/HDR10%252B/eUaGWl8V">HDR10+</a>) and is also used for HDR still picture formats. PQ is not backward compatible with the <a href="/facts/ITU-R_BT.1886/lEI5U1Hz">BT.1886</a> <a href="/facts/EOTF/6MVRUugA">EOTF</a> (i.e. the <a href="/facts/Gamma_correction/cApBLTYj">gamma curve</a> of <a href="/facts/Standard-dynamic-range_video/URDwL3DT">SDR</a>), while <a href="/facts/Hybrid_log%25E2%2580%2593gamma/9oIkzshp">HLG</a> is compatible. </p> <p>PQ is a non-linear <a href="/facts/Transfer_functions_in_imaging/6MVRUugA">transfer function</a> based on the human visual perception of <a href="/facts/Colour_banding/xV10UrTS">banding</a> and is able to produce no visible banding in 12 bits. A power function (used as EOTFs in standard dynamic range applications) extended to 10000 <a href="/facts/Candela_per_square_metre/9CaTeynY">cd/m2</a> would have required 15 bits. </p>