1、ANSI/INFOCOMM 3M-2011 Copyright 2011 by InfoComm International ANSI/INFOCOMM 3M-2011 Projected Image System Contrast Ratio InfoComm International Performance Standard 2011-06-30 Abstract This Standard defines projected image system contrast ratio and its measurement. It applies to both permanently i
2、nstalled systems and live events. It applies to front and rear projection. This Standard defines four contrast ratios based on content viewing requirements. System contrast ratio refers to the image as it is presented to viewers in a space with ambient light. Practical metrics to measure and validat
3、e the defined contrast ratios are provided. Keywords Analytical decision making; audiovisual; audiovisual standard; AV; AV system performance; basic decision making; contrast; contrast ratio; detail; digital signage; front projection; full motion video; image contrast; image quality; InfoComm; infor
4、mation; informational display; inspection; passive viewing; presentation; projected image; projector; projection; projection screen; rear projection; system contrast ratio; videoconferencing Disclaimer The application of this Standard is strictly voluntary. InfoComm International recommends its use
5、but does not assume responsibility for misinterpretation or misapplication. InfoComm International does not assume liability for disputes resulting from the non-conformance to this Standard. Conformance does not imply certification of a system. This American National Standard may be revised or withd
6、rawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this standard. Copyright 2011 by InfoComm International. This Standard may not be reproduced in whole or in part in any form for sale, promotion, o
7、r any commercial purpose, or any purpose not falling within the provisions of the U.S. Copyright Act of 1976, without prior written permission of the publisher. For permission, address a request to the Director of Performance Standards, InfoComm International. Licensed to purchaser. Single user lice
8、nse only. Copying and networking prohibited.ANSI/INFOCOMM 3M-2011 2011-06-30 2011 by InfoComm InternationalPage ii Foreword A projected image is often the centerpiece of an installed audiovisual system or a live event. Viewers depend on a projected image to convey information in adequate detail and
9、quality to achieve the content viewing requirements relative to their stated purpose or application while avoiding eyestrain or fatigue. Image contrast, a relative metric (expressed as a ratio), is one of the most important measurable criteria when assessing projected image quality. Historically, de
10、finitions of image contrast and the way contrast is measured have generated confusion. This Standard provides a clear definition of the projected system contrast in practical applications. It complements subjective assessment with new objective measurement techniques. It is important to note that no
11、 singular contrast ratio will satisfy the wide range of projected image system viewing requirements. Contrast ratio requirements vary, depending on intended purpose. As such, this Standard defines four viewing categories based on their stated purpose and establishes the required minimum contrast rat
12、ios for each viewing category. The human visual system perceives light differently than a light meter measures it. The eye is a sensitive instrument, working within a dynamic range of luminance greater than 1,000,000:1. The magnitude of this dynamic range requires significant mediation by the human
13、visual system. Light meters are typically linear instruments while the human visual systems responses to light are typically logarithmic (a similar distinction occurs in the case of sound and hearing). These factors are considered in this Standard. The quality of a projected image is not determined
14、by contrast alone, however. Image quality can be assessed using other criteria such as luminance, color rendition, resolution, video motion rendition and even how glossy a screen is. Nevertheless, contrast remains the fundamental metric to determine image quality because significant elements from ot
15、her criteria are often implicit in, or connected to, contrast. Acceptable contrast levels usually imply although not guarantee other performance metrics. Neither contrast ratio nor this Standard determines the preferred white or black levels relative to the luminance levels from surfaces adjacent to
16、 a projected image, which can influence eyestrain for users in the given environment. Users of this Standard are urged to include such ergonomic factors within their wider project considerations. This Standard is not designed to be used for competitive positioning between manufacturers or technologi
17、es. It is the system that is tested and evaluated, without reference to the component elements. This Standard applies to both front and rear projection. About InfoComm International InfoComm International is the leading nonprofit association serving the professional AV communications industry worldw
18、ide. Founded in 1939, the association offers industry expertise and market research serving press and others seeking information about the industry. Through activities that include tradeshows, education, certification, government relations, outreach, and information services, InfoComm promotes the i
19、ndustry and enhances members ability to conduct business successfully and competently. InfoComm International is the ANSI Accredited Standards Developer (ASD) dedicated to the dissemination of the knowledge of audiovisual systems performance parameters. Licensed to purchaser. Single user license onl
20、y. Copying and networking prohibited.ANSI/INFOCOMM 3M-2011 2011-06-30 2011 by InfoComm InternationalPage iii A b o u t A N S I The American National Standards Institute, Inc. (ANSI) is the national coordinator of voluntary standards development and the clearinghouse in the United States for informat
21、ion on national and international standards. An American National Standard implies a consensus of those substantially concerned with its scope and provisions. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and
22、materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered and that a concerted effort be made toward their resolution. The use of an American National Standard is complete
23、ly voluntary. Its existence does not in any respect preclude anyone, whether he or she has approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. InfoComm International Standards Development InfoComm Intern
24、ational maintains a Standards Steering Committee that provides oversight to the standards development task groups responsible for specific standards. The Standards Steering Committee is the consensus body that reports to the InfoComm International Board of Directors, whose approval is required befor
25、e standards may be submitted to ANSI. Licensed to purchaser. Single user license only. Copying and networking prohibited.ANSI/INFOCOMM 3M-2011 2011-06-30 2011 by InfoComm InternationalPage iv InfoComm International Performance Standards Program Developers At the time of this Standards development, c
26、ontributors names and affiliations are as shown: PROJECTED IMAGE SYSTEM CONTRAST RATIO PERFORMANCE STANDARD TASK GROUP Alan C. Brawn, CTS, ISF, ISF-C, Brawn Consulting, Moderator David Aleksandersen, Projection Design Tim Anderson, 3LCD Jonathan Brawn, CTS, ISF, ISF-C, Brawn Consulting Ricardo Chen,
27、 Canon USA (LCoS) Michael Davis, Texas Instruments (DLP) Richard Green, HTDS, CCP-HTPS, Rich Green, Ink (CEDIA volunteer member) Greg Jeffreys, Paradigm Audio Visual Ltd. (U.K.) Christopher Johnson, CTS-D, HTDS, AudioVisions John Meehan, Panasonic Projector Systems, Inc. David Pedigo, CEDIA Don Stew
28、art, CTS, Stewart Filmscreen Grant Stewart, CTS, Stewart Filmscreen EUROPEAN TASK GROUP Jason Brameld, Mark Johnson Consultants (U.K.) Jacob Christensen, dnp denmark A/S (Denmark) John Eden-Green,Arup Communications (U.K.) Terry Friesenborg, CTS, InfoComm International (U.S.A.) George Guthrie, Georg
29、e Guthrie Consultants Peter Hunt, Hewshott International Greg Jeffreys, Paradigm Audio Visual Ltd. (U.K.) Mark Johnson, Mark Johnson Consultants Paul Keates, Coleman Bennett International Derek Kemp, Derek Kemp Consultants Sren Weis Lindegaard, dnp denmark A/S (Denmark) Marcus Schoenrich, Mediascree
30、n (Germany) Robert Simpson, Electrosonic Hans Struwe, STRUWE (Denmark) Kevin Thompson, Coleman Bennett International INFOCOMM PROJECT COMMISSIONING WORKING GROUP (PCWG) CONTRAST RATIO TASK GROUP Tim Cape, CTS-D, Technitect, Moderator John Bailey, CTS-D, CTS-I, The Whitlock Group Rod Brown, CTS-D, In
31、foComm International Blake Brubaker, CTS, Da-Lite Screen Company, Inc. Richard G. Derbyshire, CTS, Shen Milsom Setting minimum and optimum contrast ratios relative to stated purposes; Testing and signing off completed projected image system installations; and Assisting in determining possible remedi
32、al solutions where a system is out of conformance with this Standard or otherwise inadequate for the stated purpose. This Standard defines four viewing requirement categories. These categories define the required contrast ratio relative to stated purpose or application. Licensed to purchaser. Single
33、 user license only. Copying and networking prohibited.ANSI/INFOCOMM 3M-2011 2011-06-30 Copyright 2011 by InfoComm InternationalPage 2 A viewer is defined as a person with normal/corrected vision, or normal visual acuity as defined in the normative reference, The International Council of Ophthalmolog
34、y, Visual Acuity Measurement Standard, 1984. Visual acuity is the capacity of the eye to see fine detail measured by determining the finest detail that can be detected. The four viewing requirement categories defined by this Standard are: A . Passive Viewing The viewer is able to recognize what the
35、images are on a screen and can separate the text or the main image from the background under typical lighting for the viewing environment. The content does not require assimilation and retention of detail, but the general intent is understood. There is passive engagement with the content (e.g., non-
36、critical or informal viewing of video and data). B. Basic Decision Making The viewer can make basic decisions from the displayed image. The decisions are not dependent on critical details within the image, but there is assimilation and retention of information. The viewer is actively engaged with th
37、e content (e.g., information displays, presentations containing detailed images, classrooms, boardrooms multi-purpose rooms, product illustrations). C. A n a l y t ical Decision Making The viewer can make critical decisions by the ability to analyze details within the displayed image. The viewer is
38、analytical and fully engaged with these details of the content (e.g., medical imaging, architectural/engineering drawings, forensic evidence, photographic image inspection). D. Full Motion Video The viewer is able to discern key elements present in the full motion video, including detail provided by
39、 the cinematographer or videographer necessary to support the story line and intent (e.g., home theater, business screening room, broadcast post-production). A more detailed discussion of each viewing requirement category and a summary chart can be found in Appendix 3. Exceptions A. This Standard is
40、 limited to projected image contrast ratio measurements and does not include related factors such as display luminance, image size, or display resolution. B. This Standard does not apply to direct view luminous “flat panel” displays (e.g., LCD, plasma, LED, OLED, CRT). C. This Standard does not appl
41、y to reflective technology displays (e.g., “electronic paper” displays). D. This Standard defines contrast ratio as a relative metric and measurement. It does not prescribe actual white or black luminance levels of an image since those levels should be determined relative to the ambient light level
42、of the viewing environment. Users of this Standard should address image luminance levels as part of the system design process. E. This Standard does not use any kind of full-on/off or sequential tests (typically found in sales specifications and brochures). F. Systems for which the criteria and proc
43、edures outlined in this Standard may not apply include specialized applications such as broadcast, military, entertainment and museum display. In Licensed to purchaser. Single user license only. Copying and networking prohibited.ANSI/INFOCOMM 3M-2011 2011-06-30 Copyright 2011 by InfoComm Internation
44、alPage 3 these and other specialized cases, contrast ratio criteria and measurement procedures may need to deviate from the requirements and guidelines in this document. Care should be taken when attempting to apply the methods and procedures included in this document to audiovisual systems with spe
45、cial or unusual purposes, including systems for which the primary function is not presentation of visual information to an audience. G. This Standard should be used with caution in outdoor installations where there may be large variations of uncontrollable ambient light. H. This Standard does not ad
46、dress the projected image contrast ratio required for digital cinema. The requirements of this viewing category go beyond Full Motion Video to realize the artistic vision of the videographer or cinematographer. I. This Standard does not use other contrast formulae, such as white level + black level/
47、black level. 2. Referenced Publications Normative References The following standards contain provisions that, through reference in this text, constitute provisions of this document. At the time of approval, the editions indicated below were valid. Because standards are periodically revised, users sh
48、ould consult the latest revision approved by the sponsoring Standards Developing Organizations: International Electrotechnical Commission, IEC 61947-1, Electronic projection Measurement and documentation of key performance criteria Part 1: Fixed resolution projectors (September, 2002). International
49、 Organization for Standardization, ISO 2720:1974, General Purpose and Photographic Exposure Light Meters (1974). Peter G.J. Barten Knegsel, Contrast Ratio Sensitivity of the Human Eye and its effects on Image Quality, (HV Press, 1999). Informative References The following publications contain information that supports the design and application of this Standard, but are not required provisions of the standard: H. Richard Blackwell, Contrast Thresholds of the Human Eye, J. Opt. Soc. Am. 36, 624-632, Louis Comfort Tiffany Foundation (Oyste
