1、 Recommendation ITU-R BT.2020-2 (10/2015) Parameter values for ultra-high definition television systems for production and international programme exchange BT Series Broadcasting service (television) ii Rec. ITU-R BT.2020-2 Foreword The role of the Radiocommunication Sector is to ensure the rational
2、, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommun
3、ication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Res
4、olution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information
5、 database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fi
6、xed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service system
7、s SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2015 ITU 2015 All right
8、s reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BT.2020-2 1 RECOMMENDATION ITU-R BT.2020-2 Parameter values for ultra-high definition television systems for production and international programme exchange (2012-2014-20
9、15) Scope Ultra-high definition television (UHDTV) will provide viewers with an enhanced visual experience primarily by having a wide field of view both horizontally and vertically with appropriate screen sizes relevant to usage at home and in public places. UHDTV applications require system paramet
10、ers that go beyond the levels of HDTV. This Recommendation specifies UHDTV image system parameters for production and international programme exchange. Keywords UHDTV, image system parameters, wide field of view, television system, international programme exchange The ITU Radiocommunication Assembly
11、, considering a) that digital terrestrial television broadcasting (DTTB) service has been introduced by some administrations since 1997 and can provide high quality television programmes through HDTV systems; b) that viewers expect future TV systems beyond HDTV to provide improved characteristics co
12、mpared with the current HDTV systems in terms of a more realistic sensation, greater transparency to the real world, and more accurate visual information; c) that ultra-high definition television (UHDTV) is expected to become available in the near future with, inter alia, larger screens, higher spat
13、ial/temporal resolution, wider colour gamut, wider dynamic range, etc. taking into account developments of display technology; d) that ITU-R has been studying extremely high-resolution imagery (EHRI) and an expanded hierarchy of large screen digital imagery (LSDI) image formats and has established I
14、TU-R Recommendations: Recommendation ITU-R BT.1201-1 providing the guidelines of image characteristics for extremely high-resolution imagery, and Recommendation ITU-R BT.1769 offering the parameter values for an expanded hierarchy of LSDI image formats; e) that LSDI is a system providing a display o
15、n a very large screen, typically for public viewing. This can be used in a wide variety of applications including programme presentations such as dramas, plays, sporting events, concerts, etc.; f) that EHRI is a system offering higher resolution than HDTV and can be used for both broadcasting and no
16、n-broadcasting applications (e.g. computer graphics, printing and medical applications); g) that UHDTV provides viewers with an enhanced visual experience primarily by a wider field of view that covers a considerable part of the human natural visual field with appropriate screen sizes relevant to us
17、age at home and in public places; h) that signal formats contributing to increasing the compression efficiency are desirable for UHDTV systems since they have a larger number of pixels than HDTV systems, 2 Rec. ITU-R BT.2020-2 noting that Report ITU-R BT.2246 describes the current state of ultra-hig
18、h definition television, recommends that for UHDTV programme production and international exchange, the specifications described in this Recommendation should be used1, and further recommends that if it is shown that an alternative electro-optical transfer function (EOTF) will provide significant be
19、nefits without also imposing significant disadvantages, then this Recommendation should be extended to enable use with an improved EOTF. NOTE Future consideration should be given to extend this Recommendation in a complementary manner to include extended image parameters. TABLE 1 Picture spatial cha
20、racteristics Parameter Values Picture aspect ratio 16:9 Pixel count Horizontal vertical 7 680 4 320 3 840 2 160 Sampling lattice Orthogonal Pixel aspect ratio 1:1 (square pixels) Pixel addressing Pixel ordering in each row is from left to right, and rows are ordered from top to bottom. 1 Both 3 840
21、2 160 and 7 680 4 320 systems of UHDTV will find their main applications for the delivery of television programming to the home where they will provide viewers with an increased sense of “being there” and increased sense of realness by using displays with a screen diagonal of the order of 1.5 metres
22、 or more and for large screen (LSDI) presentations in theatres, halls and other venues such as sports venues or theme parks. Presentation on tablet displays with extremely high resolution will also be attractive for viewers. The 7 680 4 320 system will provide a more enhanced visual experience than
23、the 3 840 2 160 system for a wider range of viewing environments. An increase in the efficiency of video source coding and/or in the capacity of transmission channels, compared to those currently in use, will likely be needed to deliver such programs by terrestrial or satellite broadcasting to the h
24、ome. Research is under way to achieve this goal. The delivery of such programming will initially be possible by cable or fibre. The choice of frame frequency may be influenced by the frequency of the mains power and the type of scene lighting in use, as well as by considerations related to the conve
25、rsion of programme material between higher frame rates and lower frame rates (see Report ITU-R BT.2246). Rec. ITU-R BT.2020-2 3 TABLE 2 Picture temporal characteristics Parameter Values Frame frequency (Hz) 120, 120/1.001, 100, 60, 60/1.001, 50, 30, 30/1.001, 25, 24, 24/1.001 Scan mode Progressive T
26、ABLE 3 System colorimetry Parameter Values Opto-electronic transfer characteristics before non-linear pre-correction Assumed linear(1) Primary colours and reference white(2) Chromaticity coordinates (CIE, 1931) x y Red primary (R) 0.708 0.292 Green primary (G) 0.170 0.797 Blue primary (B) 0.131 0.04
27、6 Reference white (D65) 0.3127 0.3290 (1) Picture information can be linearly indicated by the tristimulus values of RGB in the range of 0-1. (2) The colorimetric values of the picture information can be determined based on the reference RGB primaries and the reference white. 4 Rec. ITU-R BT.2020-2
28、TABLE 4 Signal format Parameter Values Signal format RGB(1) Constant luminance YCCBCCRC(2) Non-constant luminance YCBCR(3) Non-linear transfer function(4) 1),1( 0,5.4 45.0 EE EEEwhere E is voltage normalized by the reference white level and proportional to the implicit light intensity that would be
29、detected with a reference camera colour channel R, G, B; E is the resulting non-linear signal. and are the solutions to the following simultaneous equations: )2(45.05.4)1(15.455.045.0 The simultaneous equations provide the required condition to connect the two curve segments smoothly and yield = 1.0
30、9929682680944. and = 0.018053968510807 For practical purpose, the following values can be used: = 1.099 and = 0.018 for 10-bit systems = 1.0993 and = 0.0181 for 12-bit systems Derivation of YC and Y B.G.R.Y C 059306780026270 BGRY 0593.06780.02627.0 Derivation of colour difference signals RCRCCRRCRCB
31、CBCCBBCBCPYRPYRYRNNYRCPYBPYBYBNNYBC0,20,20,20,2where .7909854.00593.01 45.0 BP .9701716.019407.01 45.0 BN .4969147.02627.01 45.0 RP .8591209.017373.01 45.0 RNFor practical purpose, the following values can be used: 7910.0BP , 9702.0BN 4969.0RP , 8591.0RN 4746.18814.1YRCYBCRBRec. ITU-R BT.2020-2 5 No
32、tes du Table 4 (1) RGB may be used for programme exchange when the best quality programme production is of primary importance. (2) Constant luminance YCCBCCRC may be used when the most accurate retention of luminance information is of primary importance or where there is an expectation of improved c
33、oding efficiency for delivery (see Report ITU-R BT.2246). (3) Conventional non-constant luminance YCBCR may be used when use of the same operational practices as those in SDTV and HDTV environments is of primary importance through a broadcasting chain (see Report ITU-R BT.2246). (4) In typical produ
34、ction practice the encoding function of image sources is adjusted so that the final picture has the desired look, as viewed on a reference monitor having the reference decoding function of Recommendation ITU-R BT.1886, in the reference viewing environment defined in Recommendation ITU-R BT.2035. TAB
35、LE 5 Digital representation Parameters Values Coded signal R, G, B or Y, CB, CR or YC, CBC, CRC Sampling lattice R, G, B, Y, YC Orthogonal, line and picture repetitive co-sited Sampling lattice CB, CR or CBC, CRC Orthogonal, line and picture repetitive co-sited with each other. The first (top-left)
36、sample is co-sited with the first Y samples. 4:4:4 system 4:2:2 system 4:2:0 system Each has the same number of horizontal samples as the Y (YC) component. Horizontally subsampled by a factor of two with respect to the Y (YC) component. Horizontally and vertically subsampled by a factor of two with
37、respect to the Y (YC) component. Coding format 10 or 12 bits per component Quantization of R, G, B, Y, YC , CB, CR, CBC, CRC 8216219 nRINTRD 8216219 nGINTGD 8216219 nBINTBD 8216)(219)( nCC YYIN TYDYD 82128)(224)( nBCBBCB CCI N TCDCD 82128)(224)( nRCRRCR CCI N TCDCD6 Rec. ITU-R BT.2020-2 TABLE 5 (end
38、) Parameters Values Quantization levels Black level DR, DG, DB, DY, DYC Achromatic DCB, DCR , DCBC, DCRC Nominal Peak DR, DG, DB, DY, DYC DCB, DCR, DCBC, DCRC 10-bit coding 12-bit coding 64 512 940 64 and 960 256 2 048 3 760 256 and 3 840 Quantization level assignment Video data Timing reference 10-bit coding 12-bit coding 4 through 1 019 0-3 and 1 020-1 023 16 through 4 079 0-15 and 4 080-4 095
