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YPbPr
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<h2 id="technical-details">Technical details</h2> <p class="note">Further information: <a href="/facts/YCbCr/gfQaSqUA">YCbCr § CbCr</a></p> <p> Y ′ P ′ b P ′ r {\displaystyle Y'P'bP'r} can be derived from a gamma corrected R ′ G ′ B ′ {\displaystyle R'G'B'} signal with a typical range of 0-700 <a href="/facts/Millivolt/KF18MXP2">mV</a>. The first step is converting to Y ′ {\displaystyle Y'} , R ′ − Y ′ {\displaystyle R'-Y'} and B ′ − Y ′ {\displaystyle B'-Y'} .<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> </p><p> Y ′ {\displaystyle Y'} carries <a href="/facts/Luma_(video)/tepW85uI">luma</a> (brightness or <i>luminance</i>) and synchronization (sync) information. Luma is defined as: </p> <ul><li> Y ′ = 0.212 R + 0.701 G + 0.087 B {\displaystyle Y'=0.212R+0.701G+0.087B} for <a href="/facts/Multiple_sub-Nyquist_sampling_encoding/gyFDo4Pd">Hi-Vision</a>;</li> <li> Y ′ = 0.2126 R + 0.7152 G + 0.0722 B {\displaystyle Y'=0.2126R+0.7152G+0.0722B} for <a href="/facts/High-definition_television/AuE6FRFI">HDTV</a>;</li> <li> Y ′ = 0.299 R + 0.587 G + 0.114 B {\displaystyle Y'=0.299R+0.587G+0.114B} for <a href="/facts/Standard-definition_television/dvqEXg2A">SDTV</a>;</li></ul> <p> R ′ − Y ′ {\displaystyle R'-Y'} carries the difference between red and luma, defined as: </p> <ul><li> R ′ − Y ′ = 0.7874 R ′ − 0.7152 G ′ − 0.0722 B ′ {\displaystyle R'-Y'=0.7874R'-0.7152G'-0.0722B'} for Hi-Vision and HDTV;</li> <li> R ′ − Y ′ = 0.701 R ′ − 0.587 G ′ − 0.114 B ′ {\displaystyle R'-Y'=0.701R'-0.587G'-0.114B'} for SDTV.</li></ul> <p> B ′ − Y ′ {\displaystyle B'-Y'} carries the difference between blue and luma, defined as: </p> <ul><li> B ′ − Y ′ = − 0.2126 R ′ − 0.7152 G ′ + 0.9278 B ′ {\displaystyle B'-Y'=-0.2126R'-0.7152G'+0.9278B'} for <a href="/facts/Multiple_sub-Nyquist_sampling_encoding/gyFDo4Pd">Hi-Vision</a> and <a href="/facts/High-definition_television/AuE6FRFI">HDTV</a>;</li> <li> B ′ − Y ′ = − 0.299 R ′ − 0.587 G ′ + 0.886 B ′ {\displaystyle B'-Y'=-0.299R'-0.587G'+0.886B'} for SDTV.</li></ul> <p>These R ′ − Y ′ {\displaystyle R'-Y'} and B ′ − Y ′ {\displaystyle B'-Y'} values are then scaled to obtain normalized P ′ r {\displaystyle P'r} and P ′ b {\displaystyle P'b} values in the range of +/- 350 mV:<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> </p> <ul><li> P ′ b = ( B ′ − Y ′ ) / 1.826 {\displaystyle P'b=(B'-Y')/1.826} and P ′ r = ( R ′ − Y ′ ) / 1.576 {\displaystyle P'r=(R'-Y')/1.576} for Hi-Vision;</li> <li> P ′ b = [ 0.5 / ( 1 − 0.0722 ) ] ( B ′ − Y ′ ) {\displaystyle P'b=[0.5/(1-0.0722)](B'-Y')} and P ′ r = [ 0.5 / ( 1 − 0.2126 ) ] ( R ′ − Y ′ ) {\displaystyle P'r=[0.5/(1-0.2126)](R'-Y')} for HDTV;</li> <li> P ′ b = 0.564 ( B ′ − Y ′ ) {\displaystyle P'b=0.564(B'-Y')} and P ′ r = 0.713 ( R ′ − Y ′ ) {\displaystyle P'r=0.713(R'-Y')} for SDTV.</li></ul> <p>These formula are based on <a href="/facts/YCbCr/gfQaSqUA">SMPTE 240M</a> (240M defined EOTF and uses SMPTE 170M primaries and <a href="/facts/White_point/MP9M3NmB">white point</a>) for Hi-Vision; <a href="/facts/YCbCr/gfQaSqUA">BT.601 matrix</a> for <a href="/facts/525_lines/NTPQFv9B">525 lines</a> (SMPTE 273M) and <a href="/facts/625_lines/KXywE4Ps">625 lines</a> (<a href="/facts/PAL/t8TugcxK">ITU-R BT.1358</a>) for SDTV; and <a href="/facts/SMPTE_274M/RKpjNTm5">SMPTE 274M</a> and <a href="/facts/SMPTE_296M/HPAt5rM5">SMPTE 296M</a> for HDTV.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a> </p><p>To send a <a href="/facts/Green/gFTac7St">green</a> signal as a fourth component is redundant, as it can be derived using the blue, red and luma information. </p><p>When color signals were first added to the NTSC-encoded black and white video standard, the hue was represented by a <a href="/facts/Phase_(waves)/cpGtuVll">phase shift</a> of a color reference <a href="/facts/Subcarrier/eWqxg2h2">sub-carrier</a>. <i>P</i> for phase information or phase shift has carried through to represent color information even in the case where there is no longer a phase shift used to represent hue. Thus, the YPBPR nomenclature derives from engineering metrics developed for the NTSC color standard. </p><p>The same cables can be used for YPBPR and <a href="/facts/Composite_video/FIsE6mBz">composite video</a>. This means that the yellow, red, and white <a href="/facts/RCA_connector/A9etkIUn">RCA connector</a> cables commonly packaged with most audio/visual equipment can be used in place of the YPBPR connectors, provided the end user is careful to connect each cable to corresponding components at both ends. Also, many TVs use the green connection either for luma only or for composite video input. Since YPBPR is backward compatible with the luminance portion of composite video even with just component video decoding one can still use composite video via this input, but only luma information will be displayed, along with the <a href="/facts/Chroma_dots/ff29wNkR">chroma dots</a>. The same goes the other way around so long as 480i or 576i is used. </p> <h2 id="ypbpr-advantages">YPBPR advantages</h2> <p>Signals using YPBPR offer enough separation that no color <a href="/facts/Multiplexing/YE7hK8cw">multiplexing</a> is needed, so the quality of the extracted image is nearly identical to the pre-encoded signal. <a href="/facts/S-Video/shm26vB5">S-Video</a> and <a href="/facts/Composite_video/FIsE6mBz">composite video</a> mix the signals together by means of electronic multiplexing. Signal degradation is typical for composite video, as most display systems are unable to completely separate the signals, though HDTVs tend to perform such separation better than most <a href="/facts/Cathode-ray_tube/8NVGx5C7">CRT</a> units (see <a href="/facts/Dot_crawl/wa3TN3Um">dot crawl</a>). <a href="/facts/S-Video/shm26vB5">S-Video</a> can mitigate some of these potential issues, as its luma is transmitted separately from chroma. </p><p>Among consumer analog interfaces, only YPBPR and <a href="/facts/Analog_RGB/UEXxJ2gy">analog RGB component video</a> are capable of carrying non-<a href="/facts/Interlaced_video/YBk246TF">interlaced</a> video and resolutions higher than <a href="/facts/480i/NTPQFv9B">480i</a> or <a href="/facts/576i/KXywE4Ps">576i</a>, up to <a href="/facts/1080p/Hs7cm6Mv">1080p</a> for YPBPR. </p> <h2 id="see-also">See also</h2> <p>Graphic chipsets that generate color internally based on YPBPR: </p> <ul><li><a href="/facts/CTIA_and_GTIA/jAR5L146">CTIA and GTIA</a></li> <li><a href="/facts/MOS_Technology_VIC/1Gk6QCMW">MOS Technology VIC</a></li> <li><a href="/facts/MOS_Technology_VIC-II/3jLPsDD5">MOS Technology VIC-II</a></li> <li><a href="/facts/MOS_Technology_TED/KqtaDoIp">MOS Technology TED</a></li> <li><a href="/facts/TMS9918/pRYcgTv3">TMS9918</a></li> <li><a href="/facts/Motorola_6847/4NlpBfRN">Motorola 6847</a></li></ul> <h2 id="external-links">External links</h2> <ul><li><a href="http://www.poynton.com/ColorFAQ.html">Color FAQ</a>, Charles Poynton</li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>"YUV, YCbCr, YPbPr colour spaces". DiscoveryBiz.Net. 2024. Retrieved 2021-04-16. <a href="https://discoverybiz.net/enu0/faq/faq_YUV_YCbCr_YPbPr.html" target="_blank">https://discoverybiz.net/enu0/faq/faq_YUV_YCbCr_YPbPr.html</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Applications - High Definition Analog Component Measurement (PDF). Tektronix. 2003. <a href="https://download.tek.com/document/25W_16653_0.pdf" target="_blank">https://download.tek.com/document/25W_16653_0.pdf</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>Applications - High Definition Analog Component Measurement (PDF). Tektronix. 2003. p. 2. <a href="https://download.tek.com/document/25W_16653_0.pdf" target="_blank">https://download.tek.com/document/25W_16653_0.pdf</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Applications - High Definition Analog Component Measurement (PDF). Tektronix. 2003. p. 2. <a href="https://download.tek.com/document/25W_16653_0.pdf" target="_blank">https://download.tek.com/document/25W_16653_0.pdf</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Applications - High Definition Analog Component Measurement (PDF). Tektronix. 2003. <a href="https://download.tek.com/document/25W_16653_0.pdf" target="_blank">https://download.tek.com/document/25W_16653_0.pdf</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> </ol>