SMPTE ST 2080-3-2017 Reference Viewing Environment for Evaluation of HDTV Images.pdf

1、 Approved April 13, 2017 Copyright 2017 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue., White Plains, NY 10601 (914) 761-1100 SMPTE ST 2080-3:2017 SMPTE STANDARD Reference Viewing Environment for Evaluation of HDTV Images Page 1 of 10 pages Table of Contents Page Foreword

2、 2 Intellectual Property . 2 Introduction 2 1 Scope . 3 2 Conformance Notation . 3 3 Normative References . 3 4 Terms and Definitions 4 5 Viewing Characteristics . 4 5.1 Adaptation Time 4 5.2 Viewing Distance . 5 5.3 Viewing Angle 5 6 Surround Characteristics . 6 6.1 Surround Illumination . 6 6.2 Su

3、rround Color 6 6.3 Surround Chromaticity . 6 6.4 Surround Luminance value 6 6.5 Surround Area Extent 6 6.6 Display Physical Mounting (Informative) 6 7 General Conditions Viewing Area Decor . 7 7.1 Decor . 7 7.2 Surface Reflections . 7 7.3 Loudspeakers 7 8 Viewing Room Lighting Characteristics . 8 8.

4、1 Light Sources . 8 8.2 Lighting Reflections . 8 8.3 Working Lights . 8 8.4 Secondary Displays . 8 Annex A Surround Luminance Level (Informative) . 9 Bibliography (Informative) 10 SMPTE ST 2080-3:2017 Page 2 of 10 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an in

5、ternationally-recognized standards developing organization. Headquartered and incorporated in the United States of America, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices, and Engineering Guidelines, are prepared by

6、SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with the rules given in it

7、s Standards Operations Manual. SMPTE ST 2080-3 was prepared by Technology Committee 10E. Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essential to the implementation of this Engineering Document. However, attention is drawn to the possi

8、bility that some of the elements of this document may be the subject of patent rights. SMPTE shall not be held responsible for identifying any or all such patent rights. Introduction This section is entirely informative and does not form an integral part of this Engineering Document. The creation of

9、 television images that are intended to follow a standard of consistency in reproduction requires definition of a reference display, of a controlled viewing environment, and of a set of measurement procedures to enable consistent calibration of both display and environment. This document specifies a

10、 controlled viewing environment referred to as the Reference Viewing Environment. SMPTE ST 2080-3:2017 Page 3 of 10 pages 1 Scope This standard specifies the reference viewing environment for picture quality evaluation of HDTV images. 2 Conformance Notation Normative text is text that describes elem

11、ents of the design that are indispensable or contains the conformance language keywords: “shall“, “should“, or “may“. Informative text is text that is potentially helpful to the user, but not indispensable, and can be removed, changed, or added editorially without affecting interoperability. Informa

12、tive text does not contain any conformance keywords. All text in this document is, by default, normative, except: the Introduction, any section explicitly labeled as “Informative“ or individual paragraphs that start with “Note:” The keywords “shall“ and “shall not“ indicate requirements strictly to

13、be followed in order to conform to the document and from which no deviation is permitted. The keywords, “should“ and “should not“ indicate that, among several possibilities, one is recommended as particularly suitable, without mentioning or excluding others; or that a certain course of action is pre

14、ferred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited. The keywords “may“ and “need not“ indicate courses of action permissible within the limits of the document. The keyword “reserved” indicates a provision tha

15、t is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” and in addition indicates that the provision will never be defined in the future. A conformant implementation according to this document is one that includes all mandatory

16、 provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not implement optional provisions (“may“) and need not implement them as described. Unless otherwise specified, the order of precedence of the types of normative informatio

17、n in this document shall be as follows: Normative prose shall be the authoritative definition; Tables shall be next; then formal languages; then figures; and then any other language forms. 3 Normative References The following standards contain provisions which, through reference in this text, consti

18、tute provisions of this engineering document. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this engineering document are encouraged to investigate the possibility of applying the most recent edition of the st

19、andards indicated below. SMPTE ST 2080-1:2014, Reference White Luminance Level and Chromaticity for HDTV ISO/CIE 11664-1 (2007), Colorimetry Part 1: CIE standard colorimetric observers SMPTE ST 2080-3:2017 Page 4 of 10 pages 4 Terms and Definitions For the purposes of this document, the following te

20、rms and definitions apply. 4.1 diffuse reflection reflection of light in many directions. Note 1 to entry: Light reflected from an illuminated surface that produces a perfectly diffuse reflection will have the same luminance from all viewed directions 4.2 information display display not performing t

21、he function of a reference display. Note 1 to entry: Examples include computer displays for edit or color grading systems and continuity monitors. 4.3 reference display display intended for use in making critical aesthetic decisions concerning the image parameters of the signal being evaluated or co

22、rrected. Note 1 to entry: Specification of a reference display is outside the scope of this document. 4.4 reference viewing environment room or a portion thereof that is designed for critical viewing of images on a reference display. Note 1 to entry: When used with a calibrated reference display, im

23、ages can be consistently evaluated between environments and over time. 4.5 surround the area visible to the observer from or behind a plane coincident with and surrounding but not including the reference display(s) Note 1 to entry: A surround of defined luminance/illuminance is necessary for the cor

24、rect perception of contrast in the displayed image. The surround provides a fixed neutral visual reference that prevents the eye from changing adaptation level. 5 Viewing characteristics 5.1 Adaptation Time The observer shall be visually adapted to the viewing environment. The time allowed for the o

25、bservers adaptation should be at least 10 minutes. Note: At the operating levels specified for HDTV displays, including the surround illumination level specified in Section 6.5 below, the eye is in photopic response (cone cells). Ten minutes is sufficient time for human cone cells to adapt. Refer to

26、 Kalloniatis and Luu. SMPTE ST 2080-3:2017 Page 5 of 10 pages 5.2 Viewing Distance The observers nominal distance from the center of the reference display should be 3 to 3.2 picture heights. 5.3 Viewing Angle The observer position shall be within a horizontal angle of 30 degrees and within a vertica

27、l angle of 15 degrees from a line normal to the image plane of the reference display. (See Figure 1 and Figure 2.) Note 1: There are displays that can reproduce images accurately over a wider range of viewing angles. Users can take this into account when determining size and placement of the display

28、 within the reference viewing environment. Specification of display performance is outside the scope of this document. Note 2: In order to accommodate all viewer positions, it can be desirable to mount the display so that it can be tilted. The design of lighting in the room needs to take this into a

29、ccount. Note 3: The width of a typical armchair is 0.67 m (26 inches) as shown in Figure 1. For armchairs of this width, the distance and screen dimensions given in Figure 1 are the minimum sizes that permit viewer placement within the horizontal viewing angles specified. Width of seat: w = 0.67m Ma

30、x horizontal angle to screen: 30 degrees Distance to 1.33m wide screen: 2.32m Height of 1.33m wide screen: .75m (60” diagonal) Optimal distance to .75m screen (3.0x-3.2x): 2.25m-2.4m Dashed lines show 3.0x 3.2x screen height Figure 1 Example Horizontal Viewing Angles, Primary (Central) and Secondary

31、 Viewers Figure 2 Vertical Viewing Angle, Limits on Observer Eye Height 30 max 30 max 15 max 15 max SMPTE ST 2080-3:2017 Page 6 of 10 pages 6 Surround Characteristics 6.1 Surround Illumination The surround may be either self-illuminated or reflective (externally illuminated). 6.2 Surround Color If u

32、sed, a reflective surround should be a visually neutral surface (preferably gray). 6.3 Surround Chromaticity The surround should be illuminated with a light of a characteristic such that the light emitted or reflected matches the display chromaticity of the reference white in use (see SMPTE ST 2080-

33、1). Note: The spectral power distribution of the light emitted or reflected from the surround is unlikely to match that of the displays illuminants. Further research would be needed to determine the importance of such a match. 6.4 Surround Luminance Value The reflected light from the surround or bac

34、kground in the field of view shall have a luminance of 5.0 0.5 candelas per square meter. Surround luminance shall be measured with a spot photometer or spectroradiometer having the spectral luminance response of the standard observer (photopic vision), as defined in ISO/CIE 11664-1. The acceptance

35、angle of the measuring device shall be 2 or less. The measuring device shall have an accuracy of 3% of reading or better and a range whose minimum shall include 0.40 cd/m2. The measuring devices response to luminance variation over time shall be to properly integrate any such variation occurring at

36、frequencies at or above 24 Hz and display the arithmetic mean value. Note: This surround luminance level is significantly different than the value specified in earlier documents. Refer to Annex A for further information on this change. 6.5 Surround Area Extent The outer extent of the surround should

37、 occupy no less than 90 degrees horizontal field of view and no less than 60 degrees vertical field of view. (See Figure 3.) 6.6 Display Physical Mounting (Informative) A good practical approach is to have a reference display placed in a free-standing environment 7 cm to 2.5 screen heights in front

38、of the wall providing the visual surround. The surround receives its illumination from directly controlled and ambient lighting in the room. SMPTE ST 2080-3:2017 Page 7 of 10 pages Figure 3 Horizontal Field of View for Reference Display Surround Area 7 General Conditions Viewing Area Decor 7.1 Decor

39、 The viewing area decor and any surfaces should be matte, without dominant colors. Areas in the field of view shall be devoid of vivid colors. 7.2 Surface Reflections Reflections from all surfaces normally visible to the viewer from the operating position, except the viewing surface of the reference

40、 display, should be diffuse and should not exceed the luminance value of the surround. Reflections from all surfaces that might be visible as reflections in the reference display should have a diffuse surface reflectance of less than 50% of the luminance value of the surround. Note: This value assum

41、es that the reference displays surface has a low reflectance. Any reflections from the reference display that are visible to the viewer can interfere with the displayed image. 7.3 Loudspeakers Loudspeakers placed in the front of the room may be mounted in front of the surround, provided they are sma

42、ll with respect to the size of the reference display and are a neutral color, preferably medium to dark grey or black. SMPTE ST 2080-3:2017 Page 8 of 10 pages 8 Viewing Room Lighting Characteristics 8.1 Light Sources All light sources in use during picture assessment or adjustment should closely mat

43、ch the chromaticity of the reference white in use (see SMPTE ST 2080-1). 8.2 Lighting Reflections Reflections from light sources onto the reference display shall not cause a perceptible impairment to the displayed image from the normal viewing position. 8.3 Working Lights The production desk and con

44、trol consoles where a script is read should be illuminated to produce a reflected light level of about 100 lx (10 fc). The illumination on the general working surfaces of the production desks and consoles should be a maximum of 40 lx (4 fc). Note: This level of illumination is chosen to minimize the

45、 possibility of visible reflections from the viewing surface of the reference display, while still providing sufficient illumination for operations. 8.4 Secondary Displays The luminous surface areas of secondary displays such as information displays and touch screen control panels should produce a m

46、aximum luminance level of 100 cd/m2. The average chromaticity of the emitted light, integrated over time, should approximate the reference white in use (see SMPTE ST 2080-1), and areas of high color saturation should be limited in size, luminance, and time held on the panel. SMPTE ST 2080-3:2017 Pag

47、e 9 of 10 pages Annex A Surround Luminance Level (Informative) Predecessor documents on the display environment, specifically SMPTE RP 167:1995, cite a surround level that is 10% of reference white. However, this level is rarely if ever used; the surround is usually set at a far lower level. The que

48、stion that then arises is where the 10% level comes from, and by what means was it determined? A review of the literature, particularly in the SMPTE Journal, reveals that it can be traced to work done at the CBC and CRC in Canada in the 1960s and 70s, and was greatly influenced by the characteristic

49、s and limitations of monochrome and early color CRTs. Indeed, significant effort was expended to reduce the effective contrast range of the CRTs to at most 100:1, and the surround level was set at the center of the contrast range in order to achieve a satisfactory subjective black. The industry no longer uses CRT-based displays, and we go to significant effort to minimize or eliminate ambient illumination of the displays face. We expect our HDTV reference displays to be able to reproduce a bla