PDF (acrobat)

Report ITU-R BT.2249-5

(07/2015)

Digital broadcasting and multimedia video information systems

BT Series

Broadcasting service

(television)

ii Rep. ITU-R BT.2249-5

Foreword

The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radiofrequency 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 Radiocommunication 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

Resolution 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 database can also be found.

Series

BO

BR

BS

BT

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M

P

RA

RS

S

SA

SF

SM

Series of ITU-R Reports

(Also available online at http://www.itu.int/publ/R-REP/en )

Title

Satellite delivery

Recording for production, archival and play-out; film for television

Broadcasting service (sound)

Broadcasting service (television)

Fixed service

Mobile, radiodetermination, amateur and related satellite services

Radiowave propagation

Radio astronomy

Remote sensing systems

Fixed-satellite service

Space applications and meteorology

Frequency sharing and coordination between fixed-satellite and fixed service systems

Spectrum management

Note: This ITU-R Report was approved in English by the Study Group under the procedure detailed in

Resolution ITU-R 1.

Electronic Publication

Geneva, 2015

ITU 2015

All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU.

Rep. ITU-R BT.2249-5 1

REPORT ITU-R BT.2249-5

Digital broadcasting and multimedia video information systems

(2011-2012-05/2013-11/2013-2015)

TABLE OF CONTENTS

Page

Chapter 1

Analysis of existing video information systems for presentation of various types of broadcast and multimedia information, including VIS definition ....................

1.1

Background .........................................................................................................

1.2

External TV and video systems ..........................................................................

1.3

Large-screen digital systems ...............................................................................

1.4

Digital signage systems ......................................................................................

10

10

10

11

11

Chapter 2

New VIS with use of broadcast SDTV, HDTV, LSDI and EHRI technologies ..

2.1

Main fields of use ...............................................................................................

2.2

Public warning, disaster mitigation and relief ....................................................

Chapter 3

TV broadcasting technologies for VIS .................................................................

3.1

Extremely high resolution video system .............................................................

3.2

Video information system for handheld terminals .............................................

Chapter 4

Integration of VIS with TV broadcasting and other information services ...........

4.1

New approach to the content of outdoor TV broadcasting having regard to the technological features of large-screen VIS .........................................................

4.2

Integration of outdoor VIS with 3D TV broadcasting ........................................

4.3

Extension of the use of ITU-R Recommendations for LSDI applications to a subset of VIS applications ..................................................................................

4.4

VIS safety ...........................................................................................................

4.5

Audio accompaniment for VIS services .............................................................

Chapter 5

Assessing the quality of VIS video services ........................................................

5.1

Viewing images on VIS screens .........................................................................

5.2

Subjective assessment of the quality of images on the “indoor” VIS screens ....

5.3

Objective measurement of VIS image quality ....................................................

5.4

Future work .........................................................................................................

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12

27

38

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39

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28

34

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2 Rep. ITU-R BT.2249-5

Page

Chapter 6

VIS displays .........................................................................................................

6.1

General requirements for VIS displays ...............................................................

6.2

Main types of screen for VIS displays ................................................................

Chapter 7

Operational aspects ..............................................................................................

7.1

General ................................................................................................................

7.2

Monitoring the status of VIS signals ..................................................................

7.3

Quality control of VIS services ..........................................................................

7.4

Requirements in regard to control and measurement equipment .......................

7.5

ITU-R Recommendations in the field of VIS .....................................................

45

45

48

Annex 1

Establishment of a Rapporteur Group on digital multimedia video informational systems............................................................................................................................ 55

Annex 2

Continuation of the Rapporteur Group on digital multimedia video information systems............................................................................................................................ 57

Introduction

The term video information systems (VIS)

1

refers to multifunctional interactive systems providing high-quality reproduction of video information on screens of varying sizes in populous locations both in the open (squares, streets, stadiums, etc.) and indoors (halls, shopping centres, subway stations, etc.). Luminescent VIS screens can operate both in daylight and in the dark, in any weather and in different climatic conditions.

VIS thus brings new meaning to the concept of “outdoor television broadcasting”, with fragments of conventional TV programmes, programming designed specifically for such presentation, public warning, advertising and, generally speaking, any other services calling for the display of video information for viewing under the aforementioned conditions.

There is now a social demand for progress in the field of digital TV broadcasting, whose role in providing information to society needs to be radically enhanced.

This has given rise to the need for a new global approach to the ongoing development of digital TV broadcasting, characterized by the following features:

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1

The term VIS (video information system) entered the field of TV metrology in the 1960s as the term applied to the measurement of the quality of TV transmission from the TV camera to the point of monitoring, in which the main source of information as video information. Today, also it is used to denominate the representation of multimedia/audio-visual content (incl. broadcast content) on outdoor flat panel displays.

Rep. ITU-R BT.2249-5 3

– the basis of the approach lies in integration of the various new aspects and components, which have not yet been fully taken into account up to now, in the initial approach to the introduction of digital TV broadcasting (see Fig. 1). They will make a significant contribution to the development of this field and will make the service highly effective from an economic standpoint; the results of the research being conducted in these spheres are in many cases already approaching the level of international standardization, generating global support for the new approach; in regard to upcoming innovations, a characteristic feature of this approach is the close interlinkage between the requisite evolution of TV programme content and that of the means of its delivery and display.

The new approach is being put into practice at precisely the right moment in time. Over the next five to ten years, we will, thanks to the progress being made in digital television and radio broadcasting, broadband access (BA), interactivity, enhanced signal transmission in different environments,

Internet usage, over-the-top systems (OTT), worldwide broadcast and multimedia roaming, “cloud” technologies, mobile communication and so on, be seeing the biggest leap forward ever in the history of mass informatization.

FIGURE 1

New aspects and components of digital TV broadcasting

3D TV broadcasting systems

Interactive multifunctional 2D and 3D video information systems (VIS)

Integrated TV broadcasting and information technology system

Enhancing the attractiveness of a range of TV programmes by imparting the perception of threedimensionality to the transmitted content, thereby giving the viewer a sense of being a part of the action

Large-scale screening in populous locations, both outdoors (squares, streets, stadiums, etc.) and indoors

(railway stations, airports, subway stations, shopping centres, etc.) by broadcasting technologies

Enhancing the impact of TV broadcasting through computer technologies, BA, new file formats, packet switching, TV sets with data storage and

Internet services

Report BT.2249-01

3D TV is an important and highly sought-after capability in TV broadcasting. 3D TV technologies that are compatible with 2D systems are examined in Report ITU-R BT.2160 – Features of three-dimensional television (3DTV) video systems for broadcasting. We may look forward to the appearance of 3DTV-NP systems providing the viewer with a number (N) of additional perceptions

(P)

for example, touch (tactile sensations), temperature, vibration, and so on.

In this approach, an important role lies with the capability that has come about in recent years to provide wide-scale public screenings using interactive multifunctional 2D/3D video information systems.

The effectiveness of content development for VIS on the basis of video information obtained from different sources can be considerably enhanced through the use of file data transfer. The study of digital TV broadcasting systems using file transfer has for many years been one of the main areas of activity of ITU-R’s Broadcasting Study Group, since major advantages lie in the transition from traditional methods of TV programme signal processing and transmission to their presentation in the

4 Rep. ITU-R BT.2249-5 form of a stream of media files. Using file-based methods, it is possible to disassociate services from the network and move from the use of time division multiplexing (TDM) for content delivery to

IP-based packet switching. This speeds up the search for the required content, enhances its protection and is conducive to the integration of VIS, broadcasting, telecommunication, Internet and other services (Recommendation ITU-R BT.1888 – Basic elements of file-based broadcasting systems).

The circumstances have changed in the receiver domain in terms of the mass production of television sets capable of providing many Internet services. In addition to receiving a whole host of TV programmes, they feature, among other things, interactivity, recording of video information and personal programming on the basis of favourite themes. This does not require the use of a computer.

The time has now come when an individual, sitting at home, is able to receive a wealth of video information, while the probability of his or her choosing to watch a particular television transmission or its fragments is diminishing. Innovations associated with the introduction of the concept of worldwide broadcasting and multimedia roaming are appearing. They include “cloud”, nano and other technologies. Those technologies will lead to the creation of universal multifunctional receiver terminals.

Modern requirements of broadcasting are cardinally different from the initial ones (Annex 2 to

Doc. 6/147, 30 April 2013). The media and the means for production, transmission and reception of information and interactive signals are significantly expanded: terrestrial and satellite broadcasting, cable TV, broadcasting in fixed and mobile telecommunication networks, increased role of Internet, integrated broadcast-broadband (IBB) systems, cloud technologies, etc. The new format of reception is widely implemented. Following many years of passive reception of TV programme packets, the viewer gets the opportunity to receive the abundance of programmes and to take active part in the process and it is growing the use of VIS screens. The reception side begins to have greater influence in the general strategy of TV broadcasting. Results of SG 6 activity in the field of digital TV broadcasting are shown in Fig. 2.

Widespread usage of VIS in cooperation with Internet allows formulating the following thesis: multifunctional digital TV broadcasting – anywhere and anytime, for each and everybody.

Rep. ITU-R BT.2249-5 5

FIGURE 2

The development of multifunctional digital TV broadcasting

Video information system

(Report ITU-R BT.2249, Recommendation ITU-R BT.2000)

Multichannel sound in TV broadcasting

(Report ITU-R BS.2159)

Ultra High Definition Television

(Recommendation ITU-R BT.2020)

3DTV

(Recommendations ITU-R BT.2023, BT.2024, BT.2027)

Worldwide Broadcasting Roaming

(Question ITU-R 136/6, Study is ongoing)

File-based broadcasting

(Recommendation ITU-R BT.1888)

Integrated (Hybrid) broadcast-broadband system (IBB)

(Study is ongoing)

Public warning, disaster mitigation and relief

(Question ITU-R 118/6, Recommendation ITU-R BT.1774)

Human health protection

(Recommendation ITU-R BT.1702)

The basic principles of interactivity

(Recommendation ITU-R BT.1369)

Multimedia broadcasting

(Recommendations ITU-R BT.1788, BT.1833, BT.2016)

DVB-T2

(Recommendation ITU-R BT.1877)

Satellite TV broadcasting in the 11/12 GHz range

(Recommendations ITU-R BO.1516, BO.1784)

HDTV

(Recommendations ITU-R BT.709, BT.1120)

DTMB

ISDB

DVB

ATSC

(Recommendation ITU-R BT.1306)

Report BT.2249-02

In this regard, it is important to emphasize one of the features of VIS, which is that although a limited number of programmes are produced in multi-screen mode, the specific content and targeted advertising are sure to be viewed by a mass audience. The probability of programmes being viewed on freely accessible VIS displays is very high, since over time these will become virtually ubiquitous, offering attractive high-quality 2D/3D images under all viewing conditions.

As a result, we are seeing a new need for considerable enhancement of the content of each programme, together with a ripening need to harness the capabilities of outdoor TV.

Looking back in history, we see that the intensive development of the written press and of radio and

TV broadcasting in the twentieth century played a positive role in getting people interested in mass information. At the same time, people began to demand constant access to information and adopted a lifestyle including newspaper reading, listening to the radio and television viewing on a daily basis.

However, the twenty-first century has ushered in the next stage in information consumption. The accelerating pace of life is compelling the individual not only to keep up with events on the fly, be it in the street, on the subway escalator or in other public places, but also to process large volumes of information at high speed in order to remain abreast of events and take effective decisions. Visual imagery that is convincing, clear and universal helps the viewer to assimilate that information. This explains the growing role of the outdoor screen, it being a known fact that over 80 per cent of people’s information intake is visual.

In the past, the high demand for visual information in the populous areas led to the use and ongoing development of traditional, essentially static, means of portraying information, in the form of posters, billboards, indicator panels and so on. Today, these means exist alongside systems using electriclamp, LED, LCD, GDD and plasma screens set up in public places. However, such solutions are in

6 Rep. ITU-R BT.2249-5 many cases not capable of reproducing high-resolution/high-quality visual information, particularly as far as moving images are concerned, and this call for new approaches to the effective large-scale provision of public information.

The progress made in recent years in the development and international standardization of high-quality TV imagery has radically changed the environment, opening the way for development and creation of the long-predicted multifunctional interactive public VIS.

The new VISs enable a broadening of the broadcasting applications sphere from indoor to outdoor

 a development of the same order of significance as the transition from black-and-white to colour television to HDTV, and to further enhancements. This new stage in the field of TV broadcasting will see a considerable increase in the viewer population and play a major part in the ongoing development of the information society.

Working Party 6B commenced its studies on VIS in 2008 (Doc. 6B/7, 7 April 2008).

Question ITU-R 13/6 – Multimedia and relevant common data format, included the study of user requirements in respect of these systems as the initial stage in their international standardization

(Doc. 6/45, 22 May 2008).

At the meeting of ITU-R SG 6 held in October/November 2008, it was decided to study those requirements within the framework of Question ITU-R 45/6 – Broadcasting of multimedia and data applications (Annex 1; Doc. 6/99, 30 October 2008).

At its 2009 meetings, WP 6B decided to set up a Rapporteur group (rwp6b-rg-4) to study digital multimedia video information systems (VIS) (Annexes 1 and 2). That group developed the present report (Docs. 6B/295 and 6C/514, September 2011).

Rep. ITU-R BT.2249-5

FIGURE 3

Integrated model of the functioning of interactive video information systems

7

Program functions

Optimal integration between

TV broadcasting and own VIS programmes

Participants

TV broadcasting companies, content and advertising creators, computer services, etc.

Technical functions

Formation and transmission of

VIS signals, display, interactivity

Participants

Operators of digital telecommunication channels (existing terrestrial and satellite broadcasting infrastructures, fibre-optic links, cable links, mobile communication, display systems, etc.)

Control

VIS programme distribution control centres, warning, safety, interactivity, subscriber location, remote monitoring of image and sound quality at points of display, loading, computation, etc.

Report BT.2249-03

The development of modern VISs and their integration with broadcasting within the framework of the model’s “programme functions” caused the interest of broadcasting companies as well as content providers, advertising and computer services and Internet concerns, among others. We may anticipate changes in the advertising sphere where the use of domestic and outdoor TV screens is concerned.

Telecommunication operators are interested in the “technical functions” and “control” areas, proposing integrated solutions based on display systems, audio accompaniment, interactivity, warning and safety functions and other additional services.

The use of loudspeakers is in most cases ineffective on account of the limited public area served and the possibility of transmitting only one accompanying audio channel. Considerable advantages may be derived from individual interactive services accessed via the viewer’s standard mobile communication terminal. Such an approach has been made viable on account of the ever more widespread ownership of such terminals (there are now some five billion of them worldwide, for a global population of some 6.7 billion).

A press release issued on 25 May 2010 from the international “Expo 2010” exhibition in Shanghai reported the demonstration of a new VIS with sound accompaniment for the images on the display screens provided in various languages by means of mobile communication terminals.

Video information services for handheld receivers within local areas have been experimentally provided throughout Japan to take advantage of the widespread use of such receivers and features of the system. It would also be effective to combine presentations on large screens and on handheld terminals, where general information was presented to the public on large screens and detailed information that was supplementary was provided to individuals on handheld terminals

(see Chapter 3, § 3.2).

8 Rep. ITU-R BT.2249-5

It is now obvious that VIS will, in the very near future, usher in a new era of outdoor TV broadcasting.

Thanks essentially to a higher quality of reproduction and to the ability to transmit content files

(including possible advertisements) to hundreds of thousands of synchronized displays connected to dedicated networks and operating both in daylight and darkness, in any weather and a range of climatic conditions, VIS will replace a large number of conventional advertising posters, indicator panels and electronic facilities not equipped with VIS capabilities.

It is expected to expand the viewer base by setting up large screens at elevated locations, including airborne, with due regard for the requisite safety measures and the parameters essential for the viewing of video information will arising (see Fig. 4). The industry would be well-serviced if the information exchange were standardized.

FIGURE 4

2D/3D video information systems

1 Using TV screens

Screens of varying dimensions in static and mobile setups on land

Large screens mounted high up, including airborne and waterborne

Viewing:

in populous locations both indoors and outdoors (halls, shopping centres, stadiums, squares, streets, railway stations, airports, subways, transport stops, pharmacies, etc.)

Viewing:

in the area from which the screen is visible (stadiums, squares,

streets, embankments, during processions, demonstrations, etc.)

Information:

for mass viewing: excerpts from TV programmes (news, sport, etc.), special TV programmes for VIS, advertising, warnings, etc.

Viewing: in open areas for large-scale public information in case of emergency situations (disasters, catastrophes, etc.).

Information:

excerpts from TV programmes, special TV programmes for VIS, advertising, warnings, etc.

Information:

as required in such circumstances, with simultaneous safety of infocommunication media.

2 Using virtual images created by such systems

Report BT.2249-04

The notion of the “screen” is now complemented by that of the “virtual screen”, in which technologies are used which create a new type of 3D image in space.

Special TV programmes are already being developed for mobile TV. However, the content for mass viewing of “outdoor” TV broadcasting calls for a different approach, due to the large-area screens seen by viewers who are in motion and looking at the screen from different viewpoints, e.g. from above or below, at any time of day or night, and so on.

Thus, VIS and outdoor TV broadcasting, in meeting a current need, are also setting the seal on the start of a new era in visual information, calling for the development of standards to enable the global interaction of such systems and exchange of their specific content between different types of screen.

The large-scale screenings made possible through the widespread implementation of VIS will be a powerful driving force for the development of a whole range of high-technology sectors and will result in a significant drop in the cost of VIS components.

As we will see later, former ITU-R SG 11 (TV broadcasting), seeing what was coming, already in the early 1990s got down to work on the international standardization of interactivity and of HDTV and

EHRI systems, followed at the beginning of the twenty-first century by ITU-R SG 6, with LSDI and

UHDTV systems, among others. Virtually all of these areas have seen the development of global recommendations, and the resulting facilities are capable of reproducing the smallest details in images.

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For many years, however, for all of the assessment and measurement of TV image quality and studies into the creation of such images, the content of TV programmes and related solutions have been geared towards the reception of TV images within the home, under low-light conditions and only in

2D.

The aims of this Report are therefore:

– to demonstrate the significant demand for VIS, which, given today’s time pressures, will be capable of catering to a vast information environment on a scale never before witnessed;

– to point the way to a number of essential innovative studies and create the basis for initiating the international standardization of outdoor TV broadcasting and VIS, complementing traditional household and mobile television and moving civilization ahead towards a new stage in its development.

10 Rep. ITU-R BT.2249-5

Chapter 1

Analysis of existing video information systems for presentation of various types of broadcast and multimedia information, including VIS definition

The term VIS refers to systems for the viewing of video information on screens of varying dimensions in populous locations. The VIS family includes “external television and video”, LSDI (large screen digital imagery), DS (digital signage) systems and so on.

There are also other proposals for the definition of VIS, such as those contained in (Docs. 6/329 and

6/330 of 27 April 2011). The definition and abbreviation for digital broadcasting and multimedia video information system formulated in the final version of this report may, following adoption, be submitted to the SG 6 Rapporteur for vocabulary and terminology.

1.1 Background

As is indicated in the introduction to this report, the term VIS refers to systems used in the creation and transmission of TV and multimedia broadcasting content. It also encompasses the equipment used for reproducing content on screens of varying dimensions for viewing by the general public in areas where people congregate. Video information systems therefore fall within the scope of broadcasting services.

There are currently external TV and video systems for viewing of various kinds of essentially multimedia items relating to business, advertising, concerts, shows, sporting and other large-scale events, using screens set up in public places (squares, railway stations, stadiums, streets, parks, airports, shopping and cultural centres, shops, pharmacies, and so on).

These systems, which are based on the use of electric-lamp, light-emitting diode, liquid crystal or gas discharge screens, can be set up outdoors, for example in the street, in squares, etc. They differ from one another in terms of format and image quality, display screen technology and parameters

(resolution, brightness, contrast, colour palette, reliability, robustness vis-à-vis external conditions, etc.), viewing situations and other factors.

1.2 External TV and video systems

A number of Internet journals publish information on the light screens used in external TV and video systems, where each pixel of the image comprises a cell made up of four colour sources with red, green, dark blue and white filters. The screen resolution is determined by the distance between the lamps, which is normally 0.85 (0.75), 1, 1.15, 1.75 or 2 inches depending on the physical dimensions of the lamps and of the display. Research shows that with a resolution of 120 × 160 pixels, sometimes referred to as “sufficient resolution”, a light screen measuring over 6 × 8 m is able to display images of only standard definition, corresponding to signals produced by the PAL, SECAM and NTSC TV broadcasting systems. This offers far less scope for distinguishing between fine details in the image, especially when viewing from a long distance. Systems using light-emitting diodes or gas discharge screens have the same shortcomings.

External TV and video systems thus have limited resolution and do not allow for high-quality images.

This may seriously restrict the use of such systems for the provision of information in public places.

Rep. ITU-R BT.2249-5 11

1.3 Large-screen digital systems

Expanded hierarchy of large-screen digital imagery (LSDI) systems use UHDTV image formats of

3 840 × 2 160 and 7 680 × 4 320 pixels, in line with Recommendation ITU-R BT.2020 – Parameter values for ultra-high definition television systems for production and international programme exchange.

1.4 Digital signage systems

In recent years there has been active development of digital signage systems, used to display different types of video information on screens of varying dimensions in populous locations.

A most simplistic definition of digital signage is that of “remotely managed digital display, typically tied in with sales, marketing and advertising” [Schaeffler J. NAB Executive Technology Briefings.

Digital Signage: Software, Networks, Advertising, and Displays. A Primer for Understanding the

Business. – Published by NAB-Focal Press. – Copyright © 2008, Elsevier Inc., USA].

It is a centrally and/or remotely controlled and addressable network of typically flat-screen digital displays that deliver targeted content in the form of entertainment, information or advertisement to a designated audience by means of a combination of software and hardware resources. Other common names for Digital Signage include those such as dynamic digital signage, digital out-of-home media network, electronic signage, digital media network, digital advertising network, narrowcasting network and in-store TV network.

Digital signage is not like standard over-the-air broadcast television. Instead, modern-day digital signage typically depends on more than one video, audio or data file getting delivered concurrently to a single screen for concurrent display. Yet, free over-the-air broadcast signals can and do typically become one of many parts of a digital display, whether for digital signage or other purposes. Thus, a typical digital display may involve multiple sets of images that are displayed on the same screen at the same time, and broadcast or multichannel TV content may be part of that.

It follows from the above that digital signage systems are one branch of VIS, and that the functions they perform generally bear no relation to large-scale outdoor TV broadcasting for public viewing.

12 Rep. ITU-R BT.2249-5

Chapter 2

New VIS with use of broadcast SDTV, HDTV, LSDI and EHRI technologies

2.1 Main fields of use

The continuing development and implementation of high-definition television (HDTV) content and equipment, as part of new terrestrial digital television (DTV) services, as well as of cable-TV networks and satellite delivery to home (DBS/DTH) services worldwide, coupled with the possibility to display HDTV and higher definition content on large displays including resolution, high-contrast, and high-brightness digital display systems, enables several applications of VIS.

This digital technology is changing the nature of large audience venues allowing for the presentation of new types of content unavailable until recently to conventional viewers. Sports, concerts, dramas, plays, documentaries, cultural, educational, commercial and industrial events can now are presented to small and large audiences alongside traditionally displayed events. Audiences in many other indoor and outdoor venues can also have access to high quality digital audio and video large screen content.

This also permits the owners and operators of large audience venues where large display devices are installed, to better leverage their assets, increase their revenues, by presenting multimedia content, including delivery platforms for broadcast content.

Moreover, VIS may be implemented in digital systems from standard definition to high definition in any type of group audience, from a village hall, local club, university auditoria, schools, church halls, museums, or a sports stadium.

The development of large displays for HDTV and higher resolution, with high brightness, high contrast, is the fundamental technology enabling VIS implementations.

Most of the video information system applications are now broadly defined as digital signage.

They include:

– social events; cultural events (shows, spectacles, concerts, etc.); advertisements; forums and exhibitions; information public services and et al.

2.1.1 Collective viewing of TV broadcast programmes

The transition to HDTV programme production for the television networks results in the availability of many potential repurposed HD programmes for collective viewing on large screens. Collective viewing is a field of application for programmes broadcast by satellites to reach specific audiences in specific locations where domestic reception may not offer the same degree of quality or participation.

A typical case is represented by the fast growing number of coffee houses, hotels, restaurants, bars etc. particularly in highly frequented tourist locations all over the world, offering to customers collective vision on large screen with LSDI projectors of sport events and/or other TV programmes

(movies, serial, etc.) received by satellite. In this case, due to limited number of viewers (in general fewer than 40-50 people) low-cost LSDI projectors are used with screens of medium size.

2.1.2 Sporting events

Presently a large number of major sports stadiums are equipped with large screens, using digital TV technology for collective viewing of concurrent events in real-time and/or displaying from different view angles specific moments of the performance.

Rep. ITU-R BT.2249-5 13

The 2008 Olympics, held in Beijing and other Chinese cities, were broadcast to the crowds using a digital terrestrial TV broadcasting system conforming to standard GB20600-2006 “Framing structure, channel coding and modulation for digital terrestrial broadcasting system (DTMB)”

(ITU-R. China (People's Republic of). Chinese digital terrestrial television broadcasting system //

Doc. 6A/287, 3 December 2009). The images were displayed under stationary and mobile conditions on screens of varying dimensions.

Video information systems were also used for the 21 st

Winter Olympics in Vancouver (Canada). The main facilities were provided by six video information network operators, namely Translink, Pattison

Outdoor, CBS Outdoor, Vancouver International Airport, Canada Line and Canada Storyboard.

The Astral Media Outdoor company set up six displays, some of them double faced. They measured

3 × 10.2 m and were used for advertising.

A number of screens were set up in Richmond, carrying Media Consortium transmissions, while various screens, both indoor and outdoor, were in operation in Vancouver, likewise showing

Media Consortium transmissions. A giant screen was erected in the Convention Centre, where transmission of the Games was interleaved with advertising and promotional clips.

The Lamar company equipped the outside of over 25 buses with digital displays measuring

0.65 × 3.15 m. Those buses were on the go for 17 or 18 hours each day, with the displays running the whole time. And each of Vancouver’s 31 electric railway stations, as well as the new Canada Line metro station, were equipped with 46" liquid-crystal displays.

The Onext Media company set up some 100 displays in cafes, restaurants, shops, etc., with screens measuring between 32 and 40" and with a 60/40 ratio, the majority of them carrying advertising, while a smaller number carried sports programmes, weather reports, etc.

One of the main technology providers was Omnivex, whose software products were used for controlling video information systems at various locations in Vancouver. It set up 180 screens in the

Convention Centre.

Omnivex software was also used at Vancouver International Airport, while for the Olympics the city’s

TransLink public transport system was equipped with 170 screens in 40 locations. They were connected to the Lamar Company’s Commuter Digital Network. The communication infrastructure was set up by Bell.

Another company involved in the deployment of VIS in Vancouver was Net Display Systems, whose

PADS Solution, which had won a DIGI Award at the Digital Signage Show in New York, was used on the SkyTrain light metro system. With a track length of 49.5 km, SkyTrain is the longest automated light rapid transit system in the world, carrying an annual average of 200 000 daily passengers, equating to more than 74 million passengers per year. Large LCD panels were set up at the stations, interconnected in a network and controlled by means of video information system software.

The SEEIP (Station Entrance Emergency Information Panels) project was initiated to bring messaging to passengers before they purchase tickets, with LCD panels located at station entrances informing passengers of any problems that could delay their journey.

On the basis of the PADS Professional software from Net Display Systems, iMediaT Digital experts created a network infrastructure on the basis of a send/receive hardware technology carrying highdefinition video, audio and RS232 control signals over long distances. Signal transmission was via fibre-optic cable connected between a digital signage player PC and an LCD panel.

The PCs were networked back to a server at the main operations centre which drives the system using the PADS software and SQL server.

iMediaT Digital also developed a browser-based interface to assist field operations staff to create or edit alerts and emergency and general information messages. The system enables staff to direct

14 Rep. ITU-R BT.2249-5 custom messaging to a single screen or any combination of screens throughout the system. During normal operation, the content is designed to inform passengers of SkyTrain rules, interesting facts and other tips. During the Olympics, the screens were used to provide event information and optimize the passenger flow.

The Screenfeed company set up broadcasting networks providing access to information on unofficial team placings. This information was constantly updated (in real time) and was supplied to broadcasters free of charge. Access to it was through the Digital Signage Content Store, and involved the use of hardware designed to deliver graphical data on the four teams holding the largest number of medals.

Examples of VIS applications in sporting facilities and events are shown in Figs from 5 to 8.

FIGURE 5

Olympics. Hockey. Vancouver, 2010

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FIGURE 6

Relaying of the world football championship. Hamburg, 2010

15

FIGURE 7

LED screen at the ANZ Stadium, Sydney

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FIGURE 8

Mobile LED screen

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Large sports scoreboards can be used for displaying not only graphical information or scores but also live images of the event, highlights and replays of key moments, information about the sponsors of the club, stadium, match, competition or tournament, advertising and other video information. Given the size of such events and the huge numbers of people they bring together, such information will be viewed both by the spectators present in the stadium and on television and VIS screens set up in heavily-frequented locations, making it clear that VISs are set to become a highly effective means of outdoor TV broadcasting.

2.1.3 Examples of VIS applications for advertisements and information services

Examples of outdoor and indoor applications of VIS are given below. These are examples of potential applications of video information systems for digital video billboards and posters. Billboards or posters placed outdoors would require video displays in which the brightness and colour temperature are automatically adjusted to match the prevailing daylight or night lighting.

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FIGURE 9

Billboard in the main hall of the railway station in Geneva, Switzerland

17

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This is a large video display showing short promotional clips, mounted above the access to the escalators in the main passenger hall.

Target viewers: all passengers and other pedestrians going through the hall.

Approximate billboard size: 6.5 × 3.5 m; aspect ratio: about 16:9, “landscape” oriented.

Approximate height of billboard centre above viewers’ eye level: 6.5 m.

Approximate vertical viewing angle for a 45° elevation of the billboard centre: 20°.

Digital video system of choice for this vertical viewing angle: 1 920

1 080 (Rec. ITU-R BT.709).

FIGURE 10

Video poster with flight departures in

Leonardo da Vinci airport in Rome, Italy

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Several such digital video posters are installed in departure halls. The photo shows that the typical viewing distance is about 1 m.

Target viewers: airline passengers.

18 Rep. ITU-R BT.2249-5

Approximate poster size: 50 × 90 cm., aspect ratio: about 2:1, “portrait” oriented.

Poster height above viewers’ eye level: at eye level.

Vertical viewing angle at a viewing distance of 1 metre: 27°.

Digital video system of choice for this vertical viewing angle: 1 920

1 080 (Rec. ITU-R BT.709).

FIGURE 11

Information display panel at London’s Heathrow Airport

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FIGURE 12

Roadside information screen

19

FIGURE 13

Outdoor demonstration screen in Tokyo

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FIGURE 14

Display panel for natural disasters notification, Russia

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2.1.4 Use of VISs at large-scale public events and festivities

VISs are active “participants” at large-scale public, cultural, commercial and other events, where they serve as a means for displaying different types of video information to audience groups. VISs are also widely used during election campaigns at the federal, regional and local levels. Examples of such use are shown below.

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FIGURE 15

Motor show 2010, Paris

21

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22 Rep. ITU-R BT.2249-5

FIGURE 16

Celebration of Town Day 2010, Moscow, Russia

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FIGURE 17

Live broadcast of the wedding of Prince William on an outdoor VIS screen.

Times Square, New York, United States, 2011

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FIGURE 18

Demonstration screen at the 2010 Expo exhibition, Shanghai, China

23

FIGURE 19

Freemont street, Las Vegas, United States

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24 Rep. ITU-R BT.2249-5

2.1.5 Use of VISs at concerts and shows with large audiences and during television filming

Concert venues are these days equipped with giant VIS screens used for live transmission and for close-up replays of key moments from the event, as well as for conveying information about the organizers and sponsors of the concert or show. It is now hard to imagine a televised event or concert without the presence of a video screen or screen modules as part of the scenographic arrangement.

Examples of VIS usage at concerts and shows are given below.

FIGURE 20

“Nashestvie 2010” rock festival, Emmaus, Russia

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FIGURE 21

83 rd Oscars ceremony (2010 Oscars), Los Angeles, United States, 7 June 2011

25

FIGURE 22

Eurovision Song Contest 2011, Düsseldorf, Germany

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26 Rep. ITU-R BT.2249-5

FIGURE 23

Relaying of opera and ballet in Trafalgar Square, London

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FIGURE 24

Giant screen at Keith Richards concert

27

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2.2 Public warning, disaster mitigation and relief

The use of broadcasting facilities in connection with natural disasters is studied within the framework of Question ITU-R 118/6 – Broadcasting means for public warning, disaster mitigation and relief.

Under that Question, ITU-R developed Recommendations ITU-R ВТ.1774 and ITU-R ВО.1774, both entitled “Use of satellite and terrestrial broadcast infrastructures for public warning, disaster mitigation and relief”.

In the Recommendations, it is indicated that systems for transmission and reception should include the possibility of forcing suitably equipped and suitably primed receivers (whether switched on or in standby mode) to present programme material for disaster mitigation and relief without intervention from the listener or viewer. Such criteria are directly applicable to video information systems, which constitute components of local, regional, national and international broadcast infrastructures.

On the basis of the results obtained by ITU-R in the course of its studies on the uses of TV and multimedia broadcasting facilities, it appears desirable to provide for the possibility for VIS systems to be automatically switched to a specific video information display mode, with appropriate accompanying audio, to warn the population at large in the event of natural disasters and other emergency situations. Such video information could include details of the situation in the affected areas, guidelines for the population (e.g. escape routes) and other information designed to save lives and mitigate the effects of the disaster.

Public warning could also be provided by means of ad-hoc VIS systems involving the deployment of ground-based transportable screens and screens designed to provide a broader field of vision and be set up at elevated locations, on water, and so on. The use of aircraft is also under study.

In view of the value of VIS systems for providing public information, it would be appropriate to supplement Recommendations ITU-R BT.1774 and ITU-R BO.1774 with specific information regarding their application in the event of natural disasters. This matter should also be drawn to the attention of ITU-T Study Group 2, which is the lead study group on telecommunication for disaster relief/early warning.

28 Rep. ITU-R BT.2249-5

Chapter 3

TV broadcasting technologies for VIS

3.1 Extremely high resolution video system

Advances in information and communication technologies are enabling the development of video information systems (VIS) on the basis of ITU-R’s global standards for high-definition television

(HDTV), extremely high-resolution imagery (EHRI), ultra high-definition television (UHDTV), mobile and 3D television, and computer facilities. We need to note a number of facts related to the international standardization of such systems in this regard.

Research work is starting on developing a next-generation broadcast system that will extend the technology of HDTV, to provide greater realism and immersion, i.e. a system featuring an extremely high resolution picture of more than 4,000 scanning lines and a three-dimensional (3D) spatial sound of 22.2-multichannels.

The first demonstration models of TV facilities with large and subsequently flat screens for use in darkened rooms or for “outdoor” night-time TV broadcasting in the street were constructed on the basis of the 525- and 625-line standards.

With the first successful compression of digital HDTV signals as early as 1992 (Recommendation

ITU-R BT.709) for transmission over standard radio channels (HDTV concepts 6, 7, and 8), the Chairman of CCIR Study Group 11 proposed at a meeting of Task Group 11/4 (Washington,

13-15 October, 1992) that work be continued on enhancing TV image definition and that a start be made on the international standardization of TV systems with a resolution of over 1 000 lines, as selected for HDTV systems (Documents 11F/34 dated 10 November 1994 and 11/76 dated

1 May 1995). This was based on the predicted interest in EHRI for television, sports, computer graphics, medicine, multimedia systems, and various other fields.

This proposal resulted in global Recommendation ITU-R BT.1201 – Extremely high resolution imagery. Pixel formats of 3 840 × 2 160 and 7 680 × 4 320 were chosen for UHDTV systems on the basis of the progress made in the development of EHRI systems in Japan.

VIS can be implemented on the basis of digital TV systems using LSDI screens with a 16:9 aspect ratio and pixel formats of 3 840 × 2 160 and 7 680 × 4 320 (Recommendation ITU-R BT.2020) for theatres, concert halls, and similar environments with low illumination.

Studies at ITU-R for high resolution imagery include extremely high-resolution imagery (EHRI), an expanded hierarchy of large screen digital imagery (LSDI), and ultra-high definition television

(UHDTV). Figure 25 outlines the relationship between EHRI, LSDI, and UHDTV.

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FIGURE 25

Classification of image systems

29

EHRI-3 Expanded LSDI

EHRI-2

EHRI

EHRI-1

Expanded LSDI

UHDTV

EHRI-0

HDTV

SDTV

Screen size

LSDI

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The international standards for HDTV, UHDTV, EHRI and LSDI broadcasting systems that are dealt with in this chapter may be used as source materials for the development of ITU-R Recommendations on VIS.

3.1.1 Study on extremely high resolution video system

The extremely high resolution image system called super hi-vision is being developed by NHK

Science & Technology Research Laboratories in Japan as a future broadcasting system that will give viewers a much greater sensation of reality. The video system has 7 680 × 4 320 pixels and delivers images so real that viewers almost feel they are present at the scene of broadcasting; they may even find themselves trying to touch what is on the screen.

Studies into viewing realism have demonstrated that as the horizontal viewing angle is increased up to around 100°, viewers are increasingly affected by the displayed images. However large the screen, on the other hand, if the scan lines and pixels that make up the screen image can be detected, it becomes difficult for them to enjoy a sense of realism and immersion. Viewers with normal

20/20 vision have the ability of distinguishing between differences in viewing angle of as little as

1/60 of 1°. Thus, to ensure that viewers with normal vision (20/20), who are viewing a screen with a 16:9 aspect ratio, are not able to see the pixel-structure on the screen at a viewing angle of 100°, it is necessary to have approximately 8,000 pixels per horizontal line on a flat screen.

During the meeting of Working Party 6C (October 2011) NHK Corporation (Japan) demonstrated the ultra-high resolution system Super Hi-Vision (UHDTV). Many meeting participants unanimously noted the sense of “being there” in UHDTV pictures and confirmed high quality of the image, although the current 3DTV technology is not used.

When viewed at a distance of less than three times the screen height, 3 840 × 2 160 and 7 680 × 4 320 systems provide viewers with a greater sense of “being there” and greater sense of realness than with the 1 920 × 1 080 system and the 7 680 × 4 320 system performs the best.

Therefore, it is advisable to study in detail the impact of image resolution on depth perception.

Table 1 summarizes the specifications for extremely high resolution video systems on the basis of these kinds of investigations, as specified in Recommendation ITU-R BT.2020 – Parameter values for ultra-high definition television systems for production and international programme exchange.

The image formats, which are defined in relation to the HDTV image format with 1 920 × 1 080 pixels, offer vertical and horizontal pixel resolutions two or four times higher than those of HDTV.

The image system is hierarchical, embracing HDTV and these two new formats, with the 4k-line

30 Rep. ITU-R BT.2249-5 format representing peak resolution. Defining the formats like this enables HDTV technologies and equipment to be used, and allows systems to be efficiently constructed.

TABLE 1

Specifications for extremely high resolution video systems

System

Spatial resolution

(horizontal × vertical)

Temporal resolution

(frame rate, Hz)

2k-line

(EHRI-1)

4k-line

(EHRI-3)

3 840 × 2 160

7 680 × 4 320

24, 25, 30, 50, 60, 100 and 120

3.1.2 Development of equipment for extremely high resolution video system

Camera

A CMOS image sensor was developed that has 33 million (7 680 × 4 320) pixels and works at a frame rate of 120 Hz. The world’s first camera system that can capture images of 7 680 × 4 320/120/P,

R/G/B 4:4:4 with a wide color-gamut as specified in Recommendation ITU-R BT.2020 has been developed by utilizing three sensors. A small camera head of 2 kg using this single-chip sensor has also been developed.

The latest development is a CMOS image sensor of 133 million pixels that outputs 7 680 × 4 320 full resolution colour images at 60 fps. An ultra-high definition television camera that utilizes this sensor will be developed in the near future.

Projector

An extremely high resolution projector for the image format of 7 680 × 4 320/120/P combining three

7 680 × 4 320 LCOS panels for RGB and an RGB laser for light sources has been developed. It has a light power output of 8 000 lumens and a dynamic range of 5 000 to 1.

Flat panel display

Several LCDs for 7 680 × 4 320 have been developed including those supporting 120/P and wide colour-gamut.

3.1.3 Public viewing of extremely high resolution video system

World Exposition

House theme pavilion at the 2005 World Exposition Aichi, Japan. During the six months of the Expo,

NHK installed a super hi-vision theatre in the global two programmes enchanted 1 560 000 spectators.

The programmes were projected onto a 600-inch screen by a projector with 8 000 lumens of light output. The peak luminance on the screen was around 40 cd/m

2

, which is almost equal to that of a typical movie theatre. To enable visitors to enjoy an acute sense of reality, the theatre was designed so that they could see the screen at a viewing distance ranging from 0.75 H to 2.0 H (H was the height of the screen of 7 m), which corresponded to a horizontal viewing angle of 50-100°.

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FIGURE

26

Theatre at 2005 World Exposition

31

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Museum

A super hi-vision theatre was constructed in October 2005 at the Kyushu National Museum in Japan.

In particular, the museum set up a permanent exhibition room, called Theatre 4 000, to present its valuable artefacts with extremely high resolution imagery. Figure 27 shows the inside of the theatre.

The art collections have been placed into digital archives to compile a library of programmes. When digital archives increase substantially in scale in the future at museums and galleries all over the world, such systems should help them considerably in promoting exchanges of collections or cooperative events through global networks.

FIGURE

27

Theatre at

Kyushu

National Museum

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Music show

NHK annually broadcasts a popular music show on New Year’s Eve from NHK Hall. NHK installed a super hi-vision theatre next to the hall so that more visitors than could physically be accommodated in the hall could enjoy the programme. Singers were filmed with cameras positioned among the seated audience, and visitors to the theatre enjoyed the programme on a large screen as if they were seated in the hall.

32 Rep. ITU-R BT.2249-5

FIGURE 28

Public viewing of music show

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NHK together with NTT (Nippon Telegraph and Telephone Corporation) and NTT Communications

Corp. conducted an experiment in December 2006 to perform a super hi-vision broadcast of a live event over a long distance, through an optical IP network link at a verified data rate of 1 Gbit/s. A live programme with the uncompressed 22.2-channel audio of a four-hour musical event was transmitted on New Year’s Eve from NHK Hall, which was located next to the NHK Broadcast

Center, to a theatre that had been specially setup at the same site. MPEG-2-based encoding equipment was simultaneously used to transmit the signal at a data rate of 640 Mbits/s from Tokyo to Osaka

(a distance of approximately 500 km), where the event was enjoyed at a theatre that had been set up in the TV studio of NHK’s Osaka broadcasting station.

FIGURE 29

Simultaneous public viewing of music show

NHK Osaka studio

(450-inch screen)

NHK Hall

Fureai Hall

(520-inch screen)

IP-network (NTT)

TS data rate of 640 Mbps

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International convention

International transmissions of super hi-vision were demonstrated at IBC 2008 by the international collaboration group. The transmitted materials were presented on a 275-inch screen in a 50-seat theatre as well as on flat panel displays.

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1)

2)

Live super hi-vision pictures and sound captured in central London were sent to Amsterdam over an ultra-broadband IP network. Ultra-broadband networks are becoming more widely available, so this demonstration demonstrates the possibility of live super hi-vision content being relayed from virtually anywhere in the future. The 24-Gbit/s super hi-vision video signal was compressed to approximately 600 Mbits/s by using MPEG-2 and multiplexed with uncompressed audio into MPEG-2 TS. The interaction between the MC and reporters in

London was also able to be enjoyed.

Super hi-vision materials were transmitted via satellite from Turin to Amsterdam. Super hivision video was coded with MPEG-4 AVC and 22.2 multichannel sound was coded with

AAC. The 140 Mbit/s coded signal was divided into two TS streams and carried over two satellite transponders, using 8PSK 5/6 modulation.

A 33 million pixel full resolution projector and camera for super hi-vision were showcased at IBC

2010. Live outside broadcasting was also conducted using an optic fibre transmission system.

Uncompressed super hi-vision video and audio were transmitted live via an optic fibre network to the theatre and presented on a full resolution projector and 22.2 multichannel audio system.

International sports events

International sports events such as the Olympics and World Cup Soccer are eye-catching materials for public viewing as well as broadcasting. With a large screen and high resolution presentation of pictures and immersive sound, this system can provide the audience with realistic and immersive sensations, as if they were in the stadium.

The BBC and NHK in cooperation with the Olympic Broadcasting Service (OBS), held a public viewing of 8K super hi-vision at venues in Japan, the UK, and the USA for the 2012 London

Olympics. Live and non-live programmes through global and domestic IP networks were presented on large screens using projectors and direct-view displays (LCD and PDP) during the Olympic Games at nine presentation venues in the three countries. A summarized report can be found in Annex 3 to

Report ITU-R BT.2246.

FIFA and NHK conducted a series of live and recorded public viewings of the 2014 FIFA World Cup

Brazil in Brazil and Japan using 8K super hi-vision (Fig. 30). Pictures were projected on 300-350 inches screens and sound was reproduced by a 22.2 multichannel sound system (Fig. 31).

FIGURE 30

Transmission for public viewing of 2014 FIFA World Cup Brazil

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FIGURE 31

Public viewing site in Rio de Janeiro

Conclusion

There have been many other occasions where the public has viewed super hi-vision around the world.

Its success has demonstrated that the combination of extremely high resolution images with multichannel surround sound displayed on a large screen gives the audience the most immersive viewing experience, which is completely different from normal TV viewing.

3.2 Video information system for handheld terminals

ITU-R has produced Recommendation ITU-R BT.1833 and Report ITU-R BT.2069 on multimedia broadcasting systems for mobile reception by handheld receivers. The multimedia broadcasting systems will form one type of video information system that provides information toward handheld terminals.

One multimedia broadcasting system is Multimedia System C, a one-segment version of the ISDB-T

DTTB system. Integrated receivers with mobile phones have been wide spread in Japan for a broadcasting service called One-Seg. Users of mobile phone with One-Seg receivers are able to watch television as well as associated data services at any time and from anywhere. Broadcasting services connected to the Internet are also available.

Video information services for handheld receivers within local areas have been experimentally provided throughout Japan to take advantage of the widespread use of handheld receivers and features of the system. These services have employed the same systems and technologies as those in broadcasting but with very low transmitting power to avoid creating harmful interference to existing broadcasting services. The coverage area by one transmitter without a license has normally been within a radius of 2 to 3 m or a radius of up-to 100 m by licensed transmitters. Specific information is provided to guests at local events or local facilities. It would also be effective to combine presentations on large screens and on handheld terminals, where general information was presented to the public on large screens and detailed information that was supplementary was provided to individuals on handheld terminals.

Museum

Field trials of video information services were conducted at various museums throughout Japan.

While visitors could appreciate art, they could also obtain explanations by using their own mobile phones that functioned as broadcast receivers (see Fig. 32).

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FIGURE 32

Video information service for handheld receivers at museums

35

One-Seg mobile phone

Transmitter

Transmitter

One-Seg mobile phone

Courtesy Fujitsu Limited

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Restaurant

A trial was conducted at a restaurant to provide guests with supplementary information on the menu.

Guests could watch video of the menu at their tables by using their mobile phones as broadcast receivers.

36 Rep. ITU-R BT.2249-5

FIGURE 33

Video information service for handheld receivers at restaurant

Transmitter and One-Seg mobile phone

Courtesy Fujitsu Limited

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Local service

A number of trials have been or are being conducted throughout Japan to evaluate the potential of video information services on handheld terminals within local areas such as airports, shopping malls, underground malls, schools, stadiums, town halls, within the framework of utilizing white space.

Trials of video information services at evacuation centres are also being conducted to support refugees during disasters.

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Chapter 4

Integration of VIS with TV broadcasting and other information services

4.1 New approach to the content of outdoor TV broadcasting having regard to the technological features of large-screen VIS

Given that VIS are designed to display various kinds of broadcasting and multimedia video information with audio accompaniment, we need to study ways and means of ensuring the optimum integration of such systems with broadcasting and other information services, taking into account the specific nature of VIS content, particularly where systems to be used in the street and other outdoor settings are concerned.

Image viewing on large outdoor VIS screens is different from home viewing inasmuch as the viewers may be either stationary or in motion

sometimes at high speed, for instance in a moving vehicle

 relative to the screen. Other key considerations are the varying brightness of the ambient background at different times of the day and night and the changing distance between the moving viewer and the screen. The need to ensure comfortable viewing conditions that take account of these and other factors calls for a new approach to the content for outdoor TV broadcasting having regard to the technological specificities of large outdoor VIS screens.

An important consideration when formulating programming policy for outdoor TV broadcasting is the need to catch the attention of the information consumers, i.e. the majority of people in the city or community in question. The emotional impact of TV images seen in the street by people on the move is very different from that experienced by viewers sitting quietly at home. Grabbing the attention of moving persons calls for special programming, including so-called “attention frames” between TV fragments. Sequences should ideally last from 20 to 30 seconds and be rich in snappy emotional content

for example, short, highly topical news items from the political, social, cultural and sporting spheres, delivered without commentary, as well as “star frames”. These frames, in the form of short mini-stories based, for instance, on popular TV shows help to catch viewers’ attention for long enough to ensure that they go on to watch the subsequent video content, including possible advertisements, viewed more favourably under these circumstances than when they interrupt one’s home TV viewing.

It should be noted that special programmes recently created for mobile TV broadcasting do not meet the objectives of outdoor VIS.

It can thus be seen that VIS and the outdoor TV broadcasting currently taking shape not only respond to the challenges of our time but also testify to a new era of information viewing while opening up the way towards a new type of content.

What will be the impact of the new VIS, and why can we now consider the new age in the development of the screen arts, with TV broadcasting in pride of place, to be upon us? Traditionally, watching TV at home takes place in a darkened space of limited dimensions, whereas outdoor TV broadcasting regularly takes place in the open. This fact imposes special requirements on the producers – directors, camera operators, actors, technical operatives

of new screen stories in regard to image perception. In addition, large outdoor VIS screens call for a special kind of subject-matter and a specific approach to the presentation of information. The screen must be installed such as to be visible from all angles and, most importantly, from afar. The image, including any captioning or other graphic elements, must be discernable over a considerable distance. It should therefore be presented as close-up fragments, unlike TV programmes for home viewing, which, in addition to close-ups, will contain medium-sized and small subjects.

It is to be noted that a viewer looking at a home normally remains in one position, but is unlikely to do so in an outdoor situation. The vertical and horizontal image viewing angles change, as does the brightness of the ambient background. These factors have to be taken into account when preparing

38 Rep. ITU-R BT.2249-5 sequences for VIS, so that the composed “picture” is perceived as a whole without any distortion.

The audio accompaniment also has to be harmoniously integrated into the VIS sequence.

The shape of large outdoor screens is an important consideration. The current preference is for flat screens. However, round, concave, spherical and other forms of screen are now making their appearance. The most attractive type of screen for mass audiences is a large one

possibly round and even revolving

set up in the centre of a city square. Such features make for a considerable increase in audience numbers since the screen is visible from all angles. To increase those numbers still further, consideration is being given to the possibility of setting up outdoor screens on high ground, as well as of raising them by means of aircraft, subject to safety measures and the requisite parameters for the viewing of video information.

In some cases, large screens can be used in split-screen mode, simultaneously displaying different

TV sequences.

4.2 Integration of outdoor VIS with 3D TV broadcasting

One of the basic requirements where VIS systems are concerned is that they permit “glasses-free” viewing of different types of broadcasting and multimedia video information on the same screen, having regard to the above-mentioned special characteristics of VIS content. This is made possible through the integration and compatibility of VIS with various video services, including 3D TV broadcasting systems that are compatible with 2D broadcasting.

3D TV technologies that are compatible with 2D systems are considered in an ITU-R report on the subject (Report ITU-R BT.2160 – Features of three-dimensional television (3DTV) video systems for broadcasting). The report proposes hierarchical levels of system compatibility characterizing the features of the image as displayed using existing 2D or specialized 3D TV facilities.

Information on progress made in the development of 3D TV technology can be found in the papers of the Workshop on Three-dimensional television broadcasting, organized by ITU, EBU and SMPTE

[Toward worldwide standards for first and second generation 3D TV // Workshop on Threedimensional television broadcasting, EBU, Geneva, 30 April 2009].

The future study should concentrate on specific issues pertaining to outdoor 3D TV for VIS.

4.3 Extension of the use of ITU-R Recommendations for LSDI applications to a subset of

VIS applications

The ITU Terminology Database defines LSDI as “a family of digital imagery systems applicable to programmes such as dramas, plays, sporting events, concerts, cultural events, etc., from capture to large screen presentation in high resolution quality in appropriately equipped theatres, halls and other venues.”

The area of application of LSDI is thus limited to HDTV applications relevant to television programmes intended for large screen presentation.

Documents (6/330, 6A/482, 6B/268, 6C/447, 27 April 2011) note the following definition for VIS:

“VIS is a multifunctional interactive system displaying video information with high quality on screens of various sizes in places for viewing both in open areas (squares, streets, stadiums and other) and in large premises (halls, shopping centres, underground stations and the like)”.

The definition of VIS thus covers interactive systems (supposedly including systems that support local interactivity), high quality video information systems (supposedly including HDTV), and viewing in open areas and also in large closed premises.

Rep. ITU-R BT.2249-5 39

Hence, there is a degree of overlap among LSDI applications and some VIS applications; LSDI applications may be considered as the subset of those VIS applications that are based on local interactivity and on HDTV digital imagery for presentation of programme material.

ITU-R has issued a consistent number of Recommendations relevant to LSDI, which may be extended to cover VIS applications.

Such an extension would lead to desirable commonality of specifications and implementation approaches, where appropriate, among LSDI applications and some VIS applications, and it would also formally recognize the potential for that subset of VIS applications to also use a number of ITU-

T Recommendations in the J-series, which ITU-T SG 9 has issued for the delivery of LSDI application by means different from broadcasting (e.g. cable-casting, web-casting, etc.).

A draft new Recommendation has been prepared, intended to extend the applicability of

Recommendations that have been issued for LSDI applications, to their use for VIS applications.

4.4 VIS safety

4.4.1 Information safety

Content safety is of particular importance for VIS systems in view of their use for the provision of public information in heavily-frequented locations. The utmost attention should be paid to ensuring that information and the underlying infrastructure (communication channels, power supply systems and so on) are protected from man-made (intentional) influences which may inflict damage on all participants in the information relationship. To this end, cryptographic solutions, information backup, uninterruptible power supply systems and so on may be used.

It would be appropriate to supplement Recommendation ITU-R ВТ.1852 – Conditional-access systems for digital broadcasting with information safety methods for VIS with large outdoor screens.

To help the development of international Recommendations for effective content safety of VIS, it was proposed to collaborate with ITU-T SG 17 as the leading Study Group on telecommunication security, on studies of those systems.

4.4.2 Screen safety

Issues of information and functional safety with respect to VIS screens can be resolved by developing safety mechanisms to guard against information substitution within the display units, so as to avoid disturbances and the showing of unauthorized video sequences. Measures should likewise be taken to prevent breakdowns and mechanical damage to displays.

4.5 Audio accompaniment for VIS services

4.5.1 Audio accompaniment using loudspeakers

Systems providing sound accompaniment for VIS video content are characterized by the following features:

Provision of audio content over large, heavily-frequented areas (open spaces), with the sound sources at a considerable distance from one another (with poorly-located loudspeakers liable to produce a disturbing echo, both in the open and in large indoor spaces).

Sound-wave propagation under outdoor conditions depends to a large extent on climatic factors and atmospheric conditions (dust concentration, mist or fog, etc.).

Open spaces are always subject to different forms of acoustic noise and interference.

We may draw a distinction between concentrated, area-based, distributed and narrow-beam sound systems, the application of which will depend on the particular characteristics of any given VIS.

40 Rep. ITU-R BT.2249-5

Concentrated sound systems

Such systems are centralized and use powerful loudspeakers located at various points around the area to be served, according to its configuration. Where there is a high level of acoustic noise (streets, squares, etc.), it may be necessary to use horn loudspeakers, characterized by a high sound pressure and narrow directivity for a relatively small range of reproducible frequencies. Such sound systems are most suitable for use in open spaces, with one or more loudspeakers set up at a single spot.

According to the configuration of the space in question, they may either be stacked one above the other, thereby boosting the system’s directivity and range, or arranged in a semi-circle so as to reach a far broader area.

Horn loudspeakers provide a fairly low quality of sound. In enclosed areas with a low noise level it is therefore better to use sound systems offering a broad range of reproducible frequencies. In most cases, for example, one loudspeaker will suffice for a room up to 12 m wide. In wider rooms it will be desirable to have two or four loudspeakers, in which case they should be positioned such that their acoustic axes are parallel to one another.

Area-based systems

Area-based (decentralized) sound systems may be divided into linear and spatial systems.

Linear area-based systems should be used to deliver audio within extensive but narrow spaces such as streets. It is to be noted that such systems entail a fairly high risk of echo on account of the soundwave propagation difference between adjacent loudspeakers. An echo may originate in the direct vicinity of the loudspeaker, since it is here that the sound-wave propagation difference is greatest. In such cases, sound-wave propagation difference is to be understood as meaning overlapping between the sound received from a loudspeaker by a listener standing very close to it and the sound being emitted by an adjacent loudspeaker. For this reason, care should be taken when designing such systems to disperse the sound delivery areas and plan those areas that will not be served. Such systems are actually made up of a number of single-site systems, each serving its own area.

When similar systems are used to provide street audio by means of column loudspeakers (sound systems set up in open spaces), barely any echo is heard. This is achieved by employing a large number of column loudspeakers having a lower sound pressure than horn speakers. It is also to be noted that this solution will result in a far less uneven sound distribution than if horn speakers were used for the same street.

Spatial area-based systems are used for large areas deemed unsuited to the use of single-site sound systems. Such systems may comprise semi-circular grouped sets of horn speakers or column speakers, and provide sufficiently even sound coverage for both outdoor spaces and large indoor areas.

Distributed systems

Distributed sound systems are suitable for indoor audio delivery. They can be divided into linear and surface systems. Linear systems are used for long, narrow rooms, in which case the speaker arrangement is referred to as a chain. According to the configuration of any such room, it may receive sound from one or two chains of audio systems that are either wall mounted or mounted on suspended ceilings. The main system parameters are the height of the speaker chain fixture above the surface to which the sound is to be delivered, the distance between adjacent speakers and unevenness of sound delivery.

Surface systems are best used in large rooms with the speakers set out in a lattice arrangement.

Narrow-beam systems

Narrow-beam sound systems are suitable for indoor and outdoor audio delivery.

Rep. ITU-R BT.2249-5 41

They are widely used for audio delivery at exhibitions, museums and showrooms. The sound beam can be directed towards a specific area while at other areas the sound will be unheard.

This technology creates a high-density narrow beam of sound that can be steered with the same precision as light beam. A diameter of sound beam can be from 2 to 200 meters. Uniform sounding in case of 2 meters beam diameter will be provided by two adjacent sound emitters horizontally spaced by about 2 meters ( http://www.holosonics.com/brochure/Audio_Spotlight-Brochure.pdf

).

Distributed sound delivery to open spaces such as mass public events can be reached using sound reflectors and diffusers.

4.5.2 Personalized audio accompaniment

The audio accompaniment for VIS content that we looked at in the preceding subsection has the following main shortcomings:

Possible occurrence of echo and cross-interference between adjacent speakers.

Dependency of sound-wave propagation in open-air spaces on climatic factors and atmospheric conditions (dust levels, mist/fog, humidity, etc.).

External acoustic interference, and so on.

All of this has a considerable influence on the evenness and distinctness of the audio accompaniment experienced in the target area, in addition to which audiences may find it annoying, for example, to have to hear a succession of different languages.

The above shortcomings can to a large extent be eliminated by providing audiences with a customized interactive audio experience via standard mobile terminals. The ever-increasing ownership of such terminals (there are now some five billion of them worldwide, for a global population of 6.7 billion) makes such an approach altogether realistic.

During the international “Expo 2010” exhibition in Shanghai, the Russian pavilion featured a new multi-image VIS screen which enables the subscriber to select a given screen and the language for the audio accompaniment. All of this is set up interactively by the subscriber with the aid of a menu that is transmitted to his or her standard mobile terminal.

42 Rep. ITU-R BT.2249-5

Chapter 5

Assessing the quality of VIS video services

5.1 Viewing images on VIS screens

Comfortable viewing of TV and multimedia on VIS screens with different sizes is possible at an optimum distance between a viewer and a screen and the optimum horizontal viewing angle in accordance with Recommendation ITU-R BT.1845.

According to this Recommendation, the optimal horizontal viewing angle refers to the angle at which the image appears at the optimal viewing distance, when two contiguous pixels subtend an angle of

1 arc-min at the viewer’s eye.

The optimal viewing distance and the optimal horizontal viewing angle in image heights (H) are shown in Table 2.

TABLE 2

Optimal horizontal viewing angle and optimal viewing distance in image heights (H) for various digital image systems

Image system

(h × v)

720

485

640

480

720

576

1 024

768

1 280

720

1 400

1 050

1 920

1 080

3 840

2 160

7 680

4 320

Reference

Rec. ITU-R BT.601

VGA

Rec. ITU-R BT.601

XGA

Rec. ITU-R BT.1543

Rec. ITU-R BT.1847

SXGA+

Rec. ITU-R BT.709

Rec. ITU-R BT.2020

Rec. ITU-R BT.2020

Aspect ratio

(a : b)

4:3

4:3

4:3

4:3

16:9

4:3

16:9

16:9

16:9

Pixel aspect ratio

(r)

1

1

1

1

0.89

1

1.07

1

1

Optimal horizontal viewing angle

(



11°

11°

13°

17°

21°

23°

31°

58°

96°

Optimal viewing distance

(d)

7 H

7 H

6 H

4.5 H

4.8 H

3.3 H

3.2 H

1.6 H

0.8 H

5.2

Subjective assessment of the quality of images on the “indoor” VIS screens

The following Recommendations should be used for subjective assessments of VIS images:

1)

2)

Recommendation ITU-R BT.500 – Methodology for the subjective assessment of the quality of television pictures

Recommendation ITU-R BT.710 – Subjective assessment methods for image quality in highdefinition television

3)

4)

Recommendation ITU-R BT.1129 – Subjective assessment of standard definition digital television (SDTV) systems

Recommendation ITU-R BT.1210 – Test materials to be used in assessment of picture quality

Rep. ITU-R BT.2249-5 43

5)

6)

7)

8)

Recommendation ITU-R BT.1663 – Expert viewing methods to assess the quality of systems for the digital display of large screen digital imagery in theatres

Recommendation ITU-R BT.1702 – Guidance for the reduction of photosensitive epileptic seizures caused by television

Recommendation ITU-R BT.1729 – Common 16:9 or 4:3 aspect ratio digital television reference test pattern

Recommendation ITU-R BT.1788 – Methodology for the subjective assessment of video quality in multimedia applications

9) Recommendation ITU-R BT.2021 – Subjective methods for the assessment of stereoscopic

3DTV systems

10) Recommendation ITU-R BT.2022 – General viewing conditions for subjective assessment of quality of SDTV and HDTV television pictures on flat panel displays.

5.3 Objective measurement of VIS image quality

Possible use of the following key Recommendations should be taken into account in the objective measurement of TV and multimedia image quality on VIS display screens:

1) Recommendation ITU-R BT.1885 – Objective perceptual video quality measurement techniques for standard definition digital broadcast television in the presence of a reduced bandwidth reference

2) Recommendation ITU-R BT.1908 – Objective video quality measurement techniques for broadcasting applications using HDTV in the presence of a reduced reference signal.

5.4 Future work

The list below provides an indication of some entities within and outside ITU that have expertise relevant to the assessment of VIS video service quality and which could cooperate with ITU-R

Working Party 6B in this area of studies within ITU-R Study Group 6.

ITU bodies

ITU-R Working Party 6C

ITU-T Study Group 9

ITU-T Study Group 12

ITU-T Study Group 16

ITU-T Study Group 17

Some other international or regional standardizing bodies and forums

SMPTE – Society of Motion Picture and Television Engineers

ARIB – Association of Radio Industries and Businesses

ATSC – Advanced Television Systems Committee

ETSI – European Telecommunications Standards Institute

IEC – International Electrotechnical Commission

ISO – International Organization for Standardization

ISO/IEC JTC1/SC29/WG11 (MPEG) – Moving Picture Experts Group

44 Rep. ITU-R BT.2249-5

International or regional unions and associations of broadcasters

WBU-TC – Technical Committee of the World Broadcasting Unions

Regional unions and associations of broadcasters (ABU, ASBU, CBU, EBU, IAB, NABA, OTI,

URTNA)

Cooperation with these organizations could result in the development of international standards and

Recommendations on the quality of VIS video services.

Rep. ITU-R BT.2249-5 45

Chapter 6

VIS displays

6.1 General requirements for VIS displays

Depending on the way in which they are to be used, VIS can be divided into two main groups – indoor and outdoor.

The following characteristics of VIS displays are important from the image quality point of view

[ http://www.screens.ru/en/2012/1.html

]:

– display resolution (so called space resolution), that is pitch size for LED screens; maximal screen luminance, measured in Nits (or cd/m

2

); luminance dynamic range, e.g. possible number of image luminance levels on LED screen

(this characteristic is also called radiometric or energetic resolution); frame rate (time resolution); frame refresh rate (time resolution); spectral resolution (the number of spectral components in image).

The following operational characteristics of displays are also important

[ http://www.screens.ru/en/2012/1.html

]:

– display status monitoring system;

VIS control system software and embedded subsystem of information safety; level of electromagnetic radiation in the form of industrial radio interference from display

(mandated by national administration).

It is desirable that VIS displays have adaptive screen brightness and contrast. Displays with optimum brightness for midday will therefore be excessively bright in the morning and evening and in overcast conditions. Such over brightness causes eye fatigue, making the viewing of video information less comfortable. Another negative factor is the unnecessarily high power consumption in low outdoor light conditions, which, given the projected huge uptake of VIS, is liable to represent an undue burden on the environment.

In view of the above, it is recommended that high-quality displays that utilize video format for VIS meet the following requirements:

1) Types and formats of displayed signals

– VIS should be capable of reproducing SDTV, HDTV, UHDTV and EHRI images (see

Fig. 2 above), as well as multimedia images resolution.

– The physical resolution of a VIS display should normally not be below that of

Recommendation ITU-R ВТ.709 HDTV (1 080 × 1 920 pixels). As the high-speed communication infrastructure continues to develop, and with the emergence of highresolution video content and ongoing advances in display technology, the requirements in regard to VIS display resolution can be increased to the levels of UHDTV and EHRI.

– It is recommended that VIS displays accommodate digital video signals with a capacity not less than an 8 bit/s luminance signal for black-and-white images, and 24-bit representation of RGB colour signals if used. In the future, it may be desirable to raise these requirements to 12 and 36 bits, respectively.

– VIS screens should display images in their native aspect ratio.

46 Rep. ITU-R BT.2249-5

2)

3)

– The greater the linear dimensions, the greater the distance and area of information perception (both text and video), and hence the greater the potential size of the venue served by the display.

Pixel size

Pixel size is likewise an important consideration, as is the distance between the centres of the colour dots forming the full-colour image. The criteria for choice of pixel size depend on the way in which the VIS is to be used.

Image brightness and contrast

These characteristics are of particular importance if it is planned to use an electronic screen/display during daylight hours and it is impossible to prevent direct sunlight from falling onto it. This calls for use of a system with a screen brightness not less than

10 000 cd/m

2

. If, on the other hand, the screen does not face direct sunlight (being installed, for example, on the porch of a building with the building protecting it from the sun), a brightness of 5 000 cd/m

2 may be sufficient.

It is important to choose the brightness parameters of the video modules according to the manner in which the VIS is to be used. For standard premises (showrooms, industrial exhibitions, etc.), indoor panels with a brightness of 1 000 cd/m² are used in order to surpass other light sources by a factor of three. Higher levels of brightness will result in viewing discomfort in premises with soft lighting (theatre foyers, art galleries, etc.), where a brightness rating of at least 300 cd/m

2

is recommended. For open-air use, outdoor panels with a wide range of brightness variation are used. To ensure good image contrast, video modules must have an antiglare surface and not reflect sunlight into the viewing area. For night-time viewing, the comfortable brightness value is around 300 cd/m

2

.

Table 3 shows recommended brightness values for VIS displays:

4)

TABLE 3

Recommended brightness values for VIS displays

Type of display

Outdoor

Indoor

Brightness range

300-10 000 cd/m

2

200-1 000 cd/m

2

For optimum viewing conditions, an outdoor VIS should include an adaptive brightness and contrast capability that responds to changes in the ambient light level and average image brightness. The speed at which the signals are processed in the VIS’s digital signal processor

(DSP) and its video modules must be sufficient to display video reproduced with its source frame rate. It is preferable to use formats with progressive raster.

The vertical and horizontal viewing angles

Care should be taken to ensure that images can be viewed from a wide range of angles in the vertical and horizontal planes without appreciable changes in brightness and contrast. The choice of viewing angle for a VIS display determines the manner in which it can be used. For an indoor VIS, the maximal viewing angles usually lie between ±70° in the horizontal plane and from 0° to 45° in the vertical plane. A wider viewing angle in the horizontal plane is inadvisable owing to significant geometric distortion of the image and resulting loss of perception quality. Viewing of the image at angles greater than 45° in the vertical plane causes physical discomfort to the viewer, since a VIS screen is mounted as high up as practicable and viewing it from above is in most cases impossible. For outdoor use, the same or a smaller viewing angle is recommended, since a greater angle generally requires use of

Rep. ITU-R BT.2249-5 47

5)

6) an antiglare coating on the VIS panel, which in turn increases the power consumption. For optimum viewing, it is recommended that panels be set up at an inclination from the vertical.

Nowhere in the viewing area must images on a VIS screen present visible geometric or other distortions, including jagged edges on diagonal lines. To improve image quality in VIS, it is recommended that use be made of the picture enhancement methods that are widely and effectively used in modern TV sets, namely:

enhancement of the image’s grey tones (grey scale);

colour correction;

algorithms to enhance the on-screen portrayal of movement.

Requirements for VIS displays consisting of several modules

For display screens comprising several modules, the following additional requirements apply:

– In each module, the brightness, contrast and colour rendition parameters must be identical.

– No visible seams between video modules.

– The DSP must distribute the source image signals to the video modules without any information loss.

Additional requirements for VIS displays

– High reliability, including built-in self-diagnostics with automatic transmission of fault data to the control centre.

– Where the distance between remote control centres and VIS displays is great, it is advisable to use remote monitoring and control of the system parameters and image quality. Use of wired or wireless television cameras for direct monitoring of the on-screen image is preferable.

– High resistance to destruction (anti-vandal protection), including a built-in system for automatic transmission of attempted damage or theft alerts.

– Ability to link VIS displays into information systems for simultaneous presentation of images, including for the purpose of providing public information in emergency situations.

– Interactive information exchanges between viewers and the control centre by means of suitably-enabled mobile terminals.

– Direct broadcast capability for sporting, cultural and other large-scale events.

In many cases, the parameters for indoor and outdoor displays are the same. However, the difference between the two types of display in terms of viewing conditions is that outdoor screens are viewed from far greater distances than indoor displays. Accordingly, the requirements for the resolution (i.e. minimum pixel size) of indoor displays, which are viewed from shorter distances, are generally more exacting than for outdoor displays. At the same time, the requirements for brightness range, spectral composition of outdoor illumination and colorimetry for outdoor displays are considerably higher than for indoor displays; and the requirements for the size of the brightness and chromaticity adaptation range are generally higher for outdoor than for indoor displays. Finally, the requirements in regard to stability vis-à-vis external influences (including climatic) are more exacting for outdoor displays.

48 Rep. ITU-R BT.2249-5

6.2 Main types of screen for VIS displays

6.2.1 Screen technologies for VIS displays

The following main VIS display technologies are currently in use ( http://www.ekranua.com/ru/ ; http://www.incotex.com

):

– panels based on gas-discharge (plasma) modules; monolithic plasma display panels (PDP) (screen size up to 1.5 m); displays based on projection modules;

LED screens for outdoor use;

LED screens for indoor use, with smaller pixels (3-6 mm).

Some of these displays can be used only for alphanumeric information.

6.2.2 Trends in the ongoing evolution of displays for VIS

1) Broadening the dynamic range of the image brightness

Where indoor displays are concerned, the surrounding light intensity will vary between 200 and 1 000 cd/m

2

. To compensate for these changes, the resolution of the input signal has to be increased to 12 bits (for example using 2 bits for brightness control and 2 bits for gamma correction).

In the case of outdoor VIS displays, the brightness variation range can extend from 300 to

10 000 cd/m

2

(“day/night” mode), making it necessary to increase the bit capacity of the input signal to 15 bits (for example, 5 bits for brightness control and 2 bits for gamma correction).

Where LED screens are concerned, moreover, additional bits are required for correcting brightness scatter in pixels and modules.

2)

3)

4)

5)

Developing a new generation of LEDs on the basis of advances made in the field of nanotechnology and PDPs with calibrated brightness and colour characteristic values

Enhancing VIS image quality calls for more exacting requirements with respect to the active components of VIS screens, which will have to accommodate a broader colour range.

To reduce image artifacts, use can be made of display preprocessing (pre-correction) of image signals, which involves speeding up of the display front-end processing of the video signal in DSPs and VIS modules, or in image signal transmission networks.

For displays operating in real-time mode, it is essential to minimize the image and audio delay, for example when showing sporting events on VIS screens. Where several VISs are used simultaneously, the asynchronicity between them must be minimal and at most no more than a few frames. For this reason, sometimes satisfactory results cannot be achieved through the use of standard compression algorithms of the MPEG-2, MPEG-4/H.264 variety, since here the delay could amount to several tens of frames. A more effective solution could be to use intraframe compression algorithms of the MJPEG type, where the delay can in theory be brought down to one single frame. The very best results are achieved through the direct transmission of video signals without digital compression, but this calls for high-speed data transmission links (for example, transmission of an HDTV signal in accordance with

Standard 292M SMPTE requires a bit rate of 1.485 Gbit/s).

For best results in an outdoor environment, VIS needs to provide adaptive image brightness and colour temperature according to the brightness of the ambient light (direct sunlight, diffused light, nighttime). With this, the brightness of a VIS screen may change by a factor of 30 or more. Furthermore, to ensure comfortable viewing, the colour temperature of the image should, depending on the brightness and spectrum of the outdoor light, be adaptable

Rep. ITU-R BT.2249-5 49

6) within the range 3 000 to 9 000 K. To this end, the VIS processor must have light sensors whose signals are used for adaptively controlling the display parameters.

The pixel dimensions on a VIS screen depend on the video content being displayed.

For example, most advertisements have a low resolution in the order of 320 × 288 pixels.

Such information can be shown on displays with a pixel size of 8 to 16 mm. SDTV image signals require displays with a pixel size of 6 to 8 mm (depending on the screen size and viewing distance). For their part, HDTV, EHRI and UHDTV image signals call for the development of a new generation of VIS screens with a pixel size smaller than 3 to 4 mm.

This has become possible with the appearance of new, high-performance LEDs consuming less energy and with a high light flux, manufactured using nanotechnology.

On the basis of the foregoing, the following questions need to be considered: a) What requirements should be given for the processing of signals in outdoor VIS displays to ensure adaptive image brightness and colour temperature variation in accordance with outdoor lighting? b) c)

What requirements should be given for preprocessing of the video signal in a VIS display and for the processing of video data streams in communication lines?

What requirements should be given in regard to displays for the new generation of VIS which will ultimately accommodate a broader colour range and support x.v.Colour technology? d) What should be the optimum image viewing angles for the different types of indoor and outdoor VIS?

50 Rep. ITU-R BT.2249-5

Chapter 7

Operational aspects

7.1 General

The similarity between VIS and digital broadcasting system chains makes it possible, for VIS monitoring, to use an approach that is similar to the approach specified in Recommendation

ITU-R BT.1790 – Requirements for monitoring of broadcasting chains during operation.

Monitoring is carried out using objective control techniques and measurements while the system is in operation, i.e. it is carried out by equipment rather than by a human operator. The monitoring task is subdivided into monitoring the status of the physical signals and monitoring the perceived quality of the audiovisual content.

The main general requirements in regard to status and quality control for VIS may include the following:

– capability of in-service monitoring; applicability to the video formats in use such as SDTV, HDTV, UHDTV, EHRI, computer graphics formats, etc.; applicability to the numbers of video and audio channels in use; applicability to the transmission bit rates in use; applicability to different signal processing such as standards conversion and aspect ratio conversion;

– applicability to different sources of degradation (e.g. transmission errors, unlocked clock, improper original signals, malfunctioning of transmission links and equipment); applicability to different programme contents; applicability to the system configurations in use; traceability of the causes of malfunction, failure and degradation; availability of precise information for switching to a reserve system from the monitoring result.

7.2 Monitoring the status of VIS signals

Status monitoring consists in checking the signals in the VIS chain for conformity with standards or technical requirements while the system is operational. It allows for objective evaluation of the status and functioning of the facilities and transmission links used in the VIS chain.

The following main requirements may be cited in regard to status monitoring for VIS:

 ability to judge whether the signal including RF characteristics conforms to its specification;

– ability to detect any errors in the signal;

– ability to monitor the functioning status of equipment including malfunctions; ability to detect errors and malfunctions precisely in a short time (preferably in real-time); ability to monitor each component and equipment in the VIS chain; applicability to bit streams (e.g. MPEG-TS) and RF signals, in addition to baseband video and audio signals;

– ability to detect errors which cannot be detected by humans (e.g. occasional bit error).

Rep. ITU-R BT.2249-5 51

7.3 Quality control of VIS services

Quality control consists in objective checking of the conformity of VIS programme content and the components thereof (TV and computer images, audio, alphanumeric information, etc.) with the required quality levels according to the image scanning formats used, viewing characteristics in outdoor and indoor conditions, dimensions and height of the screen support and other factors.

The following main requirements may be cited in regard to quality control:

– ability to evaluate quantitatively the perceptual quality;

– ability to perform systematically an objective quality assessment with a precision close to subjective quality assessment by humans; ability to perform perceptual quality assessment using only bit streams (e.g. TS); ability to perform perceptual quality assessment using only the signals concerned

(i.e. non-reference methods); ability to evaluate an overall audiovisual quality (e.g. A/V relative timing); ability to detect the occurrence point of quality degradation; ability to perform perceptual quality assessment using only baseband signals; repeatability (i.e. evaluation result should not be affected by the successive signals); ability to evaluate quality in a short time or instantaneously.

7.4 Requirements in regard to control and measurement equipment

General requirements in regard to control and measurement equipment for VIS may include the following:

– the monitoring method should not disturb the monitored signals; simultaneous measurement of multiple signals or channels in use; easy maintenance; ability to log the assessment results for later use; compatibility among different manufacturers, including the log format (i.e. a standard format needs to be provided); extendability to more monitored signals and items when required; easy selection of displayed items among multiple items to be monitored; user-friendly display of the status and errors; real-time and continuous usability.

In some cases, moreover, additional requirements may be called for to cater for the particular characteristics of specific VIS and their operational features.

7.5 ITU-R Recommendations in the field of VIS

Methodologies need to be developed for the operation and monitoring of VIS chains on the basis of existing ITU Recommendations and standards of other international organizations, which may be adapted as necessary to accommodate the particular characteristics of VIS.

52 Rep. ITU-R BT.2249-5

The operational aspects of VIS applications can be based on the following ITU-R Recommendations:

1) Recommendation ITU-R BS.1387 – Method for objective measurements of perceived audio quality

This Recommendation could usefully be supplemented with new provisions relating to the progress made in audio technologies since 2001 and setting out the technical requirements with respect to audio information characteristics for VIS.

2)

3)

Recommendation ITU-R BT.1204 – Measuring methods for digital video equipment with analogue input/output

New provisions could be added to this Recommendation, relating to measuring methods in

HDTV, UHDTV, EHRI and multimedia applications (VIS).

Recommendation ITU-R BT.1683 – Objective perceptual video quality measurement techniques for standard definition digital broadcast television in the presence of a full reference

It would be useful to reflect the progress since made in the methodology for evaluating image quality, having regard to different viewing conditions, different image formats and other VISrelated aspects.

4)

5)

Recommendation ITU-R BT.1720 – Quality of service ranking and measurement methods for digital video broadcasting services delivered over broadband Internet protocol networks

It would be useful to illustrate the manner in which this Recommendation could be applied to all types/levels of VIS service.

Recommendation ITU-R BT.1359 – Relative timing of sound and vision for broadcasting

6)

7)

The need for studies on the timing of image and audio signals for different types of VIS system should be reflected.

Recommendation ITU-R BT.1729 – Common 16 × 9/4 × 3 aspect ratio digital television reference test pattern

It would be useful to supplement the recommended test patterns with elements that would enable their use in the various VIS applications.

Recommendation ITU-R BT.1691 – Adaptive image quality control in digital television systems

8)

This Recommendation could usefully be supplemented with provisions relating to the operational aspects of adaptive image quality control in the context of VIS systems.

Recommendation ITU-R BT.1692 – Optimization of the quality of colour reproduction in digital television

This Recommendation could usefully be supplemented with provisions relating to optimization of the quality of colour reproduction in the use of outdoor and indoor VIS.

Rep. ITU-R BT.2249-5 53

Conclusion

In the not-too-distant future, VISs will come to be one of the predominant means of delivering video information within population centres, above all in heavily-frequented locations. The pictures will be created by TV and computer systems. The content will be delivered to the screens by means of terrestrial and satellite radio channels, an extensive network of digital communication channels, the

Internet and other infocommunication media.

Within the framework of this historic reform, a prominent part will be played by broadcasters, as leaders in this promising area. For it is they, with their creative potential and technical facilities, that will be supplying the ever more sophisticated TV programmes and variety of content that VIS networks are able to accommodate. The participation of broadcasters in the introductory phase of outside TV broadcasting will serve not only to radically enhance their role and significance in the information society, but also to favour a fundamental expansion of the range of services on offer with considerable economic support. VIS development is likewise of interest to numerous telecommunication services for which it represents an opportunity to secure appreciable gains in traffic volumes.

The international standardization of VISs based on the application of SDTV, HDTV, LSDI, EHRI and UHDTV digital TV broadcasting technologies, coupled with computer facilities, is made for unification (or at least harmonization) of the methods used in the preparation, transmission and display of content, and for the creation of a single global network of such systems, integrating broadcasting, multimedia and other information services.

The definition that has been formulated for VISs describes them as multifunctional interactive systems intended for the preparation and transmission of TV content and multimedia broadcasting and fragments thereof, as well as of more specialized content, including advertising, alerts and so on, with the images being viewable both indoors and outdoors in heavily-frequented locations (streets, squares, parks, railway and subway stations, airports, trade and cultural centres, bus and tram stops, etc.). The integrated model for VIS operation is founded on a global approach to the development of

TV broadcasting and takes account of the system’s programme and technical functions and main participants in their implementation.

The means for assessing and measuring the quality of TV pictures, the techniques used in the production of those pictures and in the preparation of TV broadcasting content, as well as other developments in this area, have for all these years been geared solely towards the reception of TV transmissions with two-dimensional (2D) pictures under domestic conditions with low levels of lighting. It is for this reason that we now have a new line of studies focusing on the integration within

VISs of 2D/3D TV broadcasting services and other information services, with the possibility of viewing 2D and 3D images both indoors and outdoors on screens of varying dimensions and under different ambient conditions of brightness.

The integration of multifunctional digital TV broadcasting, mobile telecommunications, Internet, computer and other infocommunication services into VIS is an important contribution to the development of these systems and to the creation of a global information society, ensuring the satisfaction of the increasing social demand for information products and services. This is facilitated, in particular, by the VIS – LSDI systems developed for theatre, concert and other halls, and digital signage systems (Recommendations ITU-T H.780 “Digital signage: Service requirements and IPTVbased architecture”, H.781 “Digital signage Funktional architecture”, H.785 “Digital signage:

Requirements of disaster information services”), which are widespread in some countries. In the near future, VIS will be “ubiquitous” in cities and other settlements. Study of VIS in SG 6 is being carried out according to the following Questions:

Question ITU-R

Question ITU-R

128/6

40/6

– Digital three-dimensional (3D) TV broadcasting;

– Extremely high-resolution imagery;

54 Rep. ITU-R BT.2249-5

Question ITU-R 126/6 – Recommended operating practices to tailor television programme material to broadcasting applications at various image quality levels, display sizes and aspect ratio;

Question ITU-R 45/6 – Broadcasting of multimedia and data applications;

Question ITU-R 44/6 – Objective picture quality parameters and associated measurement and monitoring methods for digital television images;

Question ITU-R 102/6 – Methodologies for subjective assessment of audio and video quality.

Thus, ITU-R SG 6 is encouraged to accelerate the study of broadcasting and multimedia video information systems. Study Group 6 has already developed the Reports and Recommendations on

UHDTV, 3DTV, integrated broadcast-broadband (IBB) systems and other perspective broadcasting technologies, suited for VIS, and is continuing its activity in this field.

The task is therefore to improve presentation naturalness for transmitting subjects and viewer presence effect (ITU-R, Russian Federation, A study on the presence effect during UHDTV viewing,

Docs 6B/19, 6C/29, 13 April 2012; ITU-R, Working Party 6C, Draft revision of Question

ITU-R 40-2/6 – Extremely high resolution imagery, Doc. 6/14, 23 April 2012; ITU-R, Working Party

6C, draft revision of Question ITU-R 128-1/6 – Digital 3DTV systems for broadcasting, Doc. 6/22,

26 April 2012). Along with further enhancements of definition (HDTV, UHDTV systems), it is necessary to increase other key parameter values of images to reach these goals, including colour range extension, quantization levels and frame rate, together with adaptation of the presented images to the viewing environment.

In particular cases, along with an improvement of transmission methods through standard channels, new arrangements of channels for transmission of ultra-high quality images would be required.

Remote radio controlled video cameras, are very important for VIS content preparation. The viewing of broadcasting and multimedia VIS images could be highly impressive if UHDTV (4K, 8K) technology is used for its production, transmission and presentation.

Rep. ITU-R BT.2249-5 55

Annex 1

Establishment of a Rapporteur Group on digital multimedia video informational systems

Source: Annex 9 to Document 6B/106

Working Party 6B (SWG 6B-2) considered Document 6B/102 contributed by the Russian Federation.

The document shows an urgent necessity to study all the aspects and user requirements for digital multimedia video informational systems.

The study of the user requirements for digital multimedia video informational systems (VIS) on the basis of high definition television (HDTV), large screen digital imagery (LSDI) and extremely high resolution imagery (EHRI) is included in Question ITU-R 45-1/6 – Broadcasting of multimedia and data applications.

These requirements can include a variety of the video information, displayed on the screen for collective viewing of various kinds of the broadcasting multimedia and information for business, advertising, concerts, shows, sport, cultural mass activity, etc. with screens installed in multicrowded places (squares, railway stations, stadiums, streets, parks, airports trade and cultural centers, shops, drugstores, etc.) provided with the help of VIS integrated in digital TV broadcasting. It is important to also have comfortable viewing of the image on the screen of the VIS display, contribution, distribution and management of content signals and other VIS aspects.

Also of high importance for VIS is Question ITU-R 126/6 – Recommended operating practices to tailor television programme material to broadcasting applications at various image quality levels display sizes and aspect ratios.

For the consolidation of the international efforts in this area and to accelerate the standardization process, it is proposed to establish a Rapporteur Group on digital multimedia video informational systems as well as to appoint the chairman of the group.

Terms of reference of the Rapporteur Group

Study of VIS integration in digital TV broadcasting, methods for maintaining comfortable viewing of the images on screens of displays, interactivity, technologies of contribution, distribution, and management for secured content delivery and other aspects of digital multimedia video informational systems.

The analysis of existing digital multimedia video informational systems and preparing a brief progress report of existing and prospective technologies and devices, which can be suitable for these systems.

Preparation of working materials for the development of ITU-R Recommendations on digital multimedia video informational systems.

The basis for the work of the Rapporteur Group are the Recommendations ITU-R ВТ.709 – Parameter values for the HDTV standards for production and international programme exchange (Part II), ITU-

R ВТ.1201 – Extremely high resolution imagery, ITU-R BT.1769 – Parameter values for an expanded hierarchy of LSDI image formats for production and international programme exchange, ITU-

R ВТ.601 – Studio encoding parameters of digital television for standard 4:3 and wide screen 16:9 aspect ratios, and ITU-R BT.1845 – Guidelines on metrics to be used when tailoring television programmes to broadcasting applications at various image quality levels display sizes and aspect ratios.

56 Rep. ITU-R BT.2249-5

The work progress might be reflected in a report to be submitted to the next meetings of Working

Parties 6В and 6С.

Working procedures:

The Rapporteur Group should work in accordance with § 2.14 of Resolution ITU-R 1-5.

The work will be supported with a mailing list (e-mail reflector) [to be prepared by the

Secretariat].

Chairman of the Rapporteur Group

The Rapporteur Group is led by:

Professor Krivocheev (Russian Federation)

E-mail: [email protected]

as an Acting Chairman

All interested participants are encouraged to join the e-mail reflector.

Rep. ITU-R BT.2249-5 57

Annex 2

Continuation of the Rapporteur Group on digital multimedia video information systems

Source: Annex 9 to Document 6B/163

Working Party 6B received an excellent Report, Doc. 6B/133, from the acting Rapporteur Group

Chairman Professor Krivocheev. This Report has a lot of important information on digital multimedia video information systems (VIS) and proposals for revising three Questions: ITU-R 45-2/6,

ITU-R 126/6 and ITU-R 131/6.

In order to continue the Rapporteur Group, WP 6B requested Professor Krivocheev to serve as the

Chairman of the group and he kindly accepted the request.

Terms of reference of the Rapporteur Group

Study of VIS integration in digital TV broadcasting, methods for maintaining comfortable viewing of the images on screens of displays, interactivity, technologies of contribution, distribution, and management for secured content delivery and other aspects of digital multimedia video information systems.

The analysis of existing digital multimedia video information systems and preparing a brief progress report of existing and prospective technologies and devices, which can be suitable for these systems.

Preparation of working materials for the development of ITU-R Recommendations on digital multimedia video information systems.

The basis for the work of the Rapporteur Group are the Recommendations ITU-R ВТ.709 – Parameter values for the HDTV standards for production and international programme exchange (Part II),

ITU-R ВТ.1201 – Extremely high resolution imagery, ITU-R BT.1769 – Parameter values for an expanded hierarchy of LSDI image formats for production and international programme exchange,

ITU-R ВТ.601 – Studio encoding parameters of digital television for standard 4:3 and wide screen

16:9 aspect ratios, and ITU-R BT.1845 – Guidelines on metrics to be used when tailoring television programmes to broadcasting applications at various image quality levels display sizes and aspect ratios.

The work progress might be reflected in a report to be submitted to the next meetings of Working

Parties 6В and 6С.

Working procedures

The Rapporteur Group should work in accordance with § 2.14 of Resolution ITU-R 1-5.

The work will be supported with a mailing list (e-mail reflector)

Chairman of the Rapporteur Group

The Rapporteur Group is led by:

Professor Krivocheev (Russian Federation)

E-mail: [email protected]

All interested participants are encouraged to join the e-mail reflector.

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