1、-1- Rep. ITU-R BT.2003 REPORT ITU-R BT.2003 THE HARMONIZATION OF HDTV STANDARDS BETWEEN BROADCAST AND NON-BROADCAST APPLICATIONS (1 994) SECTION 1 1. Introduction This Report concerns the studies of the ITU-R, pursuant to Decision ITU-R 91, with regard to the harmonization of standards for HDTV in b
2、roadcasting and production and the standards for non-broadcast uses of HDTV*. In particular, these studies focus on: application in non-broadcast uses and the possible impacts that broadcast forms of HDTV might have on the standards and practices to be developed for non-broadcast uses in the ISO, th
3、e IEC, and the ITU-T; the constraints that might exist for the development of standards for broadcast HDTV due to non-broadcast uses. This activity will be useful input to Task Group 11/1, Working Parties 1 lD, 10-1 lR, 10-1 lS, and possibly to other groups of the ITU-R; the areas where commonality
4、between the standards for broadcast and non-broadcast uses of HDTV might be beneficial and the possible impacts of this commonality; possible areas where important differences between the standards for broadcast and non- broadcast uses may exist and possible ways to minimize their impacts. In the st
5、udies of harmonization, a number of important concerns have been identified; Selection of the parameter values for television systems may fall into two classes: (a) image-related parameters of the optical/electronic interface in the camera or the electronic/optical interface in the display. Recommen
6、dation ITU-R BT.709 is an example of this class of specification; transmission-related parameters of the encoded, filtered, redundancy-reduced description of the image, from which it may be reconstructed, albeit, less than perfectly. Harmonization activities may be different in the two areas as the
7、first relies more on fundamental, immutable concepts, while the second is constrained by service objectives and contemporary technology; (b) harmonization activities should recognize that many aspects of the work relate to basic facts, which cannot be harmonized. What is then required is an architec
8、tural structure for television images that is harmonious in respect of spatial, colorimetric and temporal characteristics, into which specific systems can be nested; * Further details of the development of standards for broadcast HDTV may be found in Recommendations lTU-R BT.709, lTU-R BT.710, ITU-R
9、 BR.713, ITU-R BR.714 and lTU-R BR.716, and Reports ITU-R BT.801,lTU-R B0.1075, lTU-R BT.1217,lTU-R CMTT.1239 and in the activities of ITU-R Task Group 11/1 and Working Parties 11/A and 11B. -2- Rep. ITU-R BT.2003 other aspects of a television system may be optimized for specific applications, indus
10、tries or contemporary technologies and their harmonization may not be helpful. Conversely, harmonization of the characteristics of the delivery mechanisms (e.g., terrestrial, satellite, cable, fibre, disc, tape) to the consumers television receiver would be beneficial; some aspects of a television s
11、ystem may not be interesting from a harmonization viewpoint, not having consequences beyond specific applications or industries; a major concern of harmonization must be the transfer of images between systems and applications. In the interchange, lack of harmonization or lack of definitions can resu
12、lt in unsatisfactory results; harmonization of standards for television and imagery may lead to economic advantages derived from commonality of equipment or components, economies of scale or other factors. The equitable distribution of these advantages may be an important factor in the acceptance of
13、 the standards; the development of standards for television and imagery may be rendered more efficient and rapid with appropriate degrees of harmonization, through the coordination of activities and the reduction of redundant effort. It is to be noted that, although the main focus of the harmonizati
14、on activity concerns television and image systems at high resolutions (HDTV/HRI), increasingly, the harmonization activity impacts television and image systems at lower levels of resolution and quality. This is particularly the case for those systems based on digital technology. SECTION 2 2. The ran
15、ge of HDTV and high-resolution imagery uses, the organizations responsible for standards and their development HDTV and high-resolution imagery (HRI) techniques have been developed to improve the quality of todays television broadcasting (production and emission), but applications of HDTV now exist
16、in many other non-broadcast areas. The following have been indicated in contributions (see Bibliography). -3- Rep. ITU-R BT.2003 I TABLE 1 SECTOR APPLICATION Education Teaching and training Advertising identify common goals, areas for coordination and possible gaps/overlaps in work programmes or sch
17、edule conflicts/misalignment; and consider proposals for joint work, coordination, liaison, etc. -4- Rep. ITU-R BT.2003 A significant output of this meeting was the conclusion that a strong liaison is needed between the ISO/IEC JTCl/SC2/WGll, ITU-T WP XV-1, and ITU-R Working Party 11B with regard to
18、 the matter of video coding, especially as it concerns equipment for home use. was held in Tokyo in September 1991 11/9-1241. The meeting was attended by representatives of the IEC/ISO JTC-1, the ITU-T and the ITU-R (SG 11, CMTT), and was a follow-up to an earlier informal gathering of similar repre
19、sentatives. The primary purpose of the meeting was to closely coordinate two areas: standardization of network issues, to ensure similar availability timeframes and technical attributes; and standardization across different video services and coding groups, to ensure consistency in technical base an
20、d service area to maximize commonality of systems and increase interworking capability. Toward these ends, the groups represented at the meeting offered reports of current and future activities in these areas, as well as indications regarding the timeframe of standards related to video network, serv
21、ice and coding. Several matters requiring attention, including matters for ITU-R Study Group 1 1, were identified at the meeting, and a plan of action to address them was agreed upon. The range of applications for high-resolution image technology is very wide, and HDTV, as defined in Report ITU-R BT
22、.801 in both psychophysical and objective terms, might be considered to be a set of specific applications of this technology. In addition, an ITU Coordination meeting on Integrated Video Services in Broadband ISDN -5- Rep. ITU-R BT.2003 TABLE 2 Activity relationship between IEC/ISO organizations and
23、 the ITU-R The harmonization of work in the different international standards organizations which are considering HDTV requires coordination. Each organization should work within its own area of interest. Thus, it will be necessary to establish joint mechanisms or a work assignment process in areas
24、where overlapping or uncertainty of responsibility exists. It is essential to this coordination task that multilateral liaison and effective sharing of appropriate common information be established. It is noted that practical limits may exist outside which harmonization may be ineffective. * Colorim
25、etry is also addressed in the CIE -6- Rep. ITU-R BT.2003 In IWP 11/9-O37 and O401 aspects of harmonization are discussed. It is stated that the work of IWP 11/9 should be governed by Decision 91, and the definition of HDTV described in Report ITU-R BT.801-4, because all mutual understanding is based
26、 on this definition. This means that ITU-R Task Group 11/4 is not a joint body which can establish common standards among relevant organizations, but a group which gathers information from various application fields of HDTV for the establishment of standards. References CCIR Documents: IWP 11/9-O06
27、(Australia), 11/9-O20 (Japan), 11/9-O33 (IEC), 11/9-O34 (Canada), 1119-037 (Japan), 11/9-O40 (Italy), 11/9-O66 (USA), 11/9-O67 (USA), 11/9-O71 (ISO), 11/9-124 (CCITT), 11/9-125 (CCIR). Bibliography CCIR Documents: IWP 11/9-O01 (Canada), 11/9-O02 (Holland), 11/9-O08 (Japan), 11/9-O09 (Japan), 1119-O1
28、0 (Japan), 11/9-01 1 (Japan), 1119-O12 (Japan), 11/9-O13 (Japan), 11/9-O14 (Japan), 11/9-O23 (Japan), 11/9-O26 (Japan), 1119-027 (Japan), 11/9-O30 (Canada), 11/9-O78 (Italy), 1119-051 (Thomson-CSF), 11/9-O52 (Thomson-CSF), 11/9-O55 (EBU), 11/9-O67 (USA), 1119-071 (ISO). SECTION 3 3. Harmonization im
29、pacts on non-broadcast applications of HDTV 3.1 Requirements and constraints 3.1.1 Introduction Harmonization of High Resolution Imaging (HRI), including HDTV, for broadcast and non- broadcast applications is possible. Furthermore, standards can facilitate this possibility of harmonization. Harmoniz
30、ation is possible due to recent progress in technology. Techniques that may be useful are: digital technology; broadest feasible gamuts and ranges for parameters; extensibility and scalability; and image descriptor. Harmonization is important since the growth rate of non-broadcasting high-definition
31、 imaging technology applications is considerably faster than the evolution in broadcast applications. Harmonization efforts must consider the broader range of imaging parameter requirements for non- broadcast applications. Further, they must recognize that images are captured, created, stored, and t
32、ransmitted in many ways. The amount of film and hardcopy (paintings, printing, etc.) images in the world is very large and will continue to grow. -7- Rep. ITU-R BT.2003 It would be best to concentrate harmonization efforts on those areas and parameters that are not too application-oriented. For exam
33、ple, such parameters may include colorimetry, pixel aspect ratio, compression, resolution, flexible image encoding, and a header identifier. Architectures and standards developed in this way can be of benefit for many years and for many steps in technological progress. 3.1.2 Aspect ratios applicatio
34、ns for high-resolution imagery. Common aspect ratios which have been used for high-resolution images include 4:3, 16:9, square, split screen, and multi-screen. Other detailed variations in aspect ratio exist in paintings and printing of images. Some applications have found a square aspect ratio usef
35、ul. Motion pictures also have a variety of aspect ratio formats. IWP 11/9-O38 and O521 indicate that desire for a variety of formats is cited in many 3.1.3 Scanning parameters (scanning parameters for computer workstations and personal computers) IWP 11/9-038,041,051 and O521 indicate that computer
36、displays are widely adopting a Common computer display resolutions include 1024 x 768, 1152 x 900, 1280 x 1024, and Some of these horizontal and vertical display resolutions are divisible by 128. IWP 1 1/9-041, and 05 i indicate that an evolutionary standards architecture would be multiple-window co
37、ncept. 640 x 480. Recent workstations are also supporting 1600 x 1280, and 2048 x 2048. useful that could support future advances beyond 2048 x 2048 to possibly 4096 and even 8192 in some applications. Such applications may be non-real time for the near future, but may someday be able to display ful
38、l motion. resolution formats would be beneficial for many industries. Currently, these systems are relatively incompatible. All such computer displays are progressively scanned (non-interlaced). Interlaced HDTV implementations may have compatibility difficulties with any computer workstation type of
39、 display. Frame display rates on these workstations are commonly 60 Hz, 66 Hz, 70 Hz, 72 Hz, and 76 Hz. Here again, compatibility with HDTV frame or field rates has to be solved. 8 bits per colour, for a total of 24 bits per pixel (16 Million total simultaneous colors) is the typical state-of-the-ar
40、t for full colour computer displays. However, the workstation itself can compute pixel values more precisely with 10 or 12 bits per colour. IWP 11/9-0521 indicates that for some applications, 12 bits may be needed. Compatibility of all of these formats to both display and generate HDTV and other hig
41、h 3.1.4 Colorimetry representation of high definition imagery is central to cross industry harmonization. The more colour spaces which are included in a standardized representation, the more systems will be able to avail themselves of accurate colour exchange and reproduction. It may, therefore, be
42、best to consider a wide range for the colour space, rather than optimizing for current equipment, when approaching the issue of harmonizing HDTV across many applications. IWP 11/9-O62 and O631 indicate that the specification of the colorimetry used for a digital -8- Rep. ITU-R BT.2003 Further, the s
43、tandardization of an appropriate white point for all or some industries is a significant issue for investigation. If a single white reference colour temperature definition for digital imagery data were possible for nearly all applications, this would greatly improve harmonization of colour exchange
44、and reproduction. imagery, or is extensible to these uses, affords the best rendition of the dynamic range of the illuminance of each colour. Extensibility may be useful to consider in this regard, in that both camera sensors and displays are likely to improve their dynamic range as technology conti
45、nues to develop. Some form of logarithmic representation may merit examination. The use of all positive values in both R,G,B and Y,U,V, seems to be the most broadly compatible digital value bit representation. The use of linear representations for appropriate points (such as filtering) in the signal
46、 processing should be considered to offer such valuable characteristics as constant luminance. IWP11/9-IWP 11/9-O62 and O631 indicate that compatibility between capture, storage, and printing colorimetry is a challenge when attempting to utilize various imagery sources. Full colour compatibility may
47、 require a colour gamut which reaches all of the colors represented on each system component. Also, a transfer function which encompasses the broadest number of uses of high resolution 3.1.5 Square pixels utilize a square pixel aspect ratio. This affords economy in display processing. It further aff
48、ords a standard which enhances exchange of imagery due to commonality of sampling aspect ratio. Examination of pixel aspect ratios such as 1/2,2/3,3/2, and 2/1, may also find these to be useful in some circumstances. IWP 11/9-O01 and O511 indicate that in the computer world, the greater majority of
49、displays IWP 11/9-0511 also indicates that for some applications, a square sampling distribution is seen as not absolutely necessary. 3.1.6 Header descriptor have to be exchanged between various media and uses. Cross industry harmonization may be served by searching for a universal descriptor convention that accommodates current and future uses. An example of this is shown in IWP 11/9-0101. IWP 11/9-O41 and O661 indicate that a broad range of visual information exists, and it will 3.1.7 Scalability and compatibility requirements, and it is desirable to exchange data and progra
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