1、 ANSI E1.54, PLASA Standard for Color Communication in Entertainment Lighting i Photo/2014-5006r2 ANSI E1.54 - 2015 PLASA Standard for Color Communication in Entertainment Lighting Photo/2014-5006r2 (Version of 21 November 2014) Approved as an American National Standard by the ANSI Board of Standard
2、s Review on 21 May 2015 2015 PLASA North America ANSI E1.54, PLASA Standard for Color Communication in Entertainment Lighting ii Photo/2014-5006r2 Notice and Disclaimer PLASA does not approve, inspect, or certify any installations, procedures, equipment or materials for compliance with codes, recomm
3、ended practices or standards. Compliance with a PLASA standard or recommended practice is the sole and exclusive responsibility of the manufacturer or provider and is entirely within their control and discretion. Any markings, identification, or other claims of compliance do not constitute certifica
4、tion or approval of any type or nature whatsoever by PLASA. PLASA neither guarantees nor warrants the accuracy or completeness of any information published herein and disclaim liability for any personal injury, property or other damage or injury of any nature whatsoever, whether special, indirect, c
5、onsequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this document. In issuing and distributing this document, PLASA does not either (a) undertake to render professional or other services for or on behalf of any person or entity, or (b) undertak
6、e any duty to any person or entity with respect to this document or its contents. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstance. Pu
7、blished By: PLASA North America 630 Ninth Avenue, Suite 609 New York, NY 10036 USA Phone: 1-212-244-1505 Fax: 1-212-244-1502 Email: standards.naplasa.org ANSI E1.54, PLASA Standard for Color Communication in Entertainment Lighting iii Photo/2014-5006r2 The PLASA Technical Standards Program The PLASA
8、 Technical Standards Program was created to serve the PLASA membership and the entertainment industry in technical standards related matters. The goal of the Program is to take a leading role regarding technology within the entertainment industry by creating recommended practices and standards, moni
9、toring standards issues around the world on behalf of our members, and improving communications and safety within the industry. PLASA works closely with the technical standards efforts of other organizations within our industry, as well as representing the interests of PLASA members to ANSI, UL, and
10、 the NFPA. The Technical Standards Program is accredited by the American National Standards Institute. The Technical Standards Council (TSC) was established to oversee and to coordinate the Technical Standards Program. Made up of individuals experienced in standards-making work from throughout our i
11、ndustry, the Council approves all projects undertaken and assigns them to the appropriate working group. The Technical Standards Council employs a Technical Standards Manager to coordinate the work of the Council and its working groups as well as maintain a “Standards Watch” on behalf of members. Wo
12、rking groups include: Control Protocols, Electrical Power, Floors, Fog and Smoke, Followspot Position, Photometrics, Rigging, and Stage Lifts. PLASA encourages active participation in the Technical Standards Program. There are several ways to become involved. If you would like to become a member of
13、an existing working group, as have over four hundred people, you must complete an application which is available from the PLASA office. Your application is subject to approval by the working group and you will be required to actively participate in the work of the group if you join as a voting membe
14、r. This includes responding to letter ballots and attending meetings. Membership in PLASA is not a requirement. You can also become involved by requesting that the TSC develop a standard or a recommended practice in an area of concern to you. The Photometrics Working Group, which authored this stand
15、ard, consists of a cross section of entertainment industry professionals representing a diversity of interests. PLASA is committed to developing consensus-based standards and recommended practices in an open setting. The Technical Standard Program (TSP) is financially supported by PLASA and by compa
16、nies and individuals who make undirected donations to the TSP. Contributing companies and individuals who have helped fund the TSP are recognized as “Investors in Innovation.“ The Investors in Innovation when this standard was published on 21 May 2015 include these companies and individuals: VISIONA
17、RY ($10,000 and up) LDI ProSight Specialty Insurance United States Institute for Theatre Technology INNOVATOR ($3,000 - $9,999) Altman Lighting, Inc. Barbizon Electric ETC Mountain Productions Inc. Texas Scenic Company DEVELOPER ($1,000 - $2,999) Bigger Hammer Production Services Candela Controls In
18、c Stage Equipment Theatre Safety Programs; U Mitch Hefter; Royal Philips; MP Jefferey Knox; Schuler Shook; DE Michael Lay; Royal Philips; MP Wendy Luedtke; Rosco Laboratories; MP Kimberly Corbett Oates; Schuler Shook; DE Mark Ravenhill; GLP German Light Products GmbH; MP Karl G. Ruling; Unit 12 Prod
19、uctions; DE Markus Salm; GLP German Light Products GmbH; MP Larry Schoeneman; DesignLab Chicago, Inc.; DR Ken Vannice; Ken Vannice LLC; G Mike Wagner; Arnold MP Mike Wood; Mike Wood Consulting LLC; G Observer (non-voting) members: Robert Barbagallo; Solotech Inc.; DR Mos Benaglia; Clay Paky S.P.A.;
20、MP David Bertenshaw; G Lee J. Bloch; Bloch Design Group, Inc.; U Andr Broucke; Andr Broucke; G Bill Ellis; Candela Controls, Inc.; U Gregg Esakoff; Electronic Theatre Controls, Inc.; MP Charles H. Green; U Tim Hansen; Oasis Stage Werks; U A C Hickox; Domingo Gonzalez Associates; U Ed Hyatt; Boston I
21、llumination Group; CP Joseph M. Good III; Spectrum Professional Services; G Frank Kjr Jensen; Harman International Industries; MP Dennis Thykjr Jrgensen; Martin Professional A/S; MP Francois Juliat; Robert Juliat; MP Hiroshi Kita; Marumo Electric Co., Ltd.; MP Bill Klages; New Klages Inc.; U Phil Kl
22、apwyk; IATSE Local 891; U Larry Lieberman; Vision Quest Lighting; CP Rick Loudenburg; Barbizon Companies; DR Doug MacDonald; Designlab Chicago Inc.; DR Jim McHugh; Humboldt State University; U John T. Ryan; Altman Stage Lighting; MP Ford Sellers; Chauvet Lighting; MP Keith Sklar; Actors Equity Assoc
23、iation; G Ben Sweet-Block; Royal Philips; MP Robert Timmerman; Royal Philips; MP Garrett Young; Prism Projection, Inc.; MP Interest category codes: CP = custom-market producer DE = designer DR = dealer rental company G = general interest MP = mass-market producer U = user ANSI E1.54, PLASA Standard
24、for Color Communication in Entertainment Lighting vii Photo/2014-5006r2 Table of contents 1 Scope 1 2 Requirements (normative) 1 2.1 PLASA Standard Color Space, RGB Primaries and White Point . 1 2.1.1 Color Space . 1 2.1.2 RGB Primaries . 1 2.1.3 White point . 1 2.2 HSI (Hue, Saturation, Intensity)
25、Control Definitions 1 2.3 Communication of Color 1 2.3.1 Communication of RGB Values . 1 2.3.2 Communication of x,y Coordinates 1 2.4 Handling of Commands to Produce Colors Outside of a Luminaires Gamut . 2 3 The Need for Standardization in Color Communication (informative) 2 4 Color Space Choice Ex
26、planation (informative) 2 5 Color Math Examples (informative) 3 5.1 RGB Control 3 5.2 Convert PLASA RGB to CIE 1931 (x, y): 4 5.2 HSI Control . 4 ANSI E1.54, PLASA Standard for Color Communication in Entertainment Lighting 1 Photo/2014-5006r2 1 Scope This standard specifies a standardized color spac
27、e, and defines the locations of the RGB primaries and the White Point for the purpose of facilitating the communications between lighting controllers and color-changing luminaires. It offers a standardized way of specifying color. The method is generic and is neither manufacturer-specific nor color
28、technology-specific. 2 Requirements (normative) 2.1 PLASA Standard Color Space, RGB Primaries and White Point 2.1.1 Color Space The Color Space shall be CIE 1931 x,y 2.1.2 RGB Primaries The RGB Primaries shall be defined in the CIE 1931 Color Space by the following coordinates: Red: x=0.7347, y=0.26
29、53 Green: x=0.1596, y=0.8404 Blue: x=0.0366, y=0.0001 2.1.3 White point The White Point shall be defined in the CIE 1931 Color Space by the following coordinates: x=0.4254, y=0.4044 2.2 HSI (Hue, Saturation, Intensity) Control Definitions Hue is an angular measurement that varies for 0 to 360. For t
30、he purposes of this PLASA Standard, reference hue angles are defined as follows: Hue of 0 = Full Red (RGB = 100,0,0) Hue of 120 = Full Green (RGB = 0,100,0) Hue of 240 = Full Blue (RGB = 0,0,100) 2.3 Communication of Color 2.3.1 Communication of RGB Values The preferred method of communicating color
31、 in this standard is by sending RGB (red, blue, green) values. 2.3.2 Communication of x,y Coordinates Using CIE 1931 x,y color coordinates for communicating color is permissible in this standard, but is not the preferred method. If CIE 1931 x,y color coordinates are used for communication, then they
32、 shall be sent as scaled values where 100% in the communication system shall be interpreted as 0.7347 for x, and 0.8341 for y. For example, if 16 bit values are used for communication, then the command mapping is as follows: x = 0: command value = 0 x = 0.7347: transmitted value for x = FFFFh y = 0:
33、 command value = 0 y = 0.8341: transmitted value for y = FFFFh ANSI E1.54, PLASA Standard for Color Communication in Entertainment Lighting 2 Photo/2014-5006r2 2.4 Handling of Commands to Produce Colors Outside of a Luminaires Gamut It is recommended, but not required, that when a luminaire receives
34、 a control command to create a color outside its gamut, that it produce a color that is as close to that hue as possible for the luminaire, but at lower saturation. 3 The Need for Standardization in Color Communication (informative) There is no standardization of entertainment luminaire color gamut.
35、 That gamut is usually defined, in the case of RGB LED based fixtures, by the wavelengths of the specific red, green, and blue emitters used. With different wavelength emitters being used, there is no commonality of RGB control settings between luminaires. A single set of RGB or HSI values sent to 2
36、0 different luminaires will render 20 different colors. Figure 1 shows the different RGB gamuts from three luminaires. Figure 1 Arbitrary RGB color gamuts defined by Specific LED emitters. As luminaire and LED technologies have advanced, many manufacturers are now calibrating their luminaires to an
37、absolute reference and would be capable of referring the mixed colors produced by their luminaires back to a standardized color definition. There is no particular commercial benefit to a single manufacturer in using one color definition over another, however there is considerable benefit to the enti
38、re industry if all manufacturers were to use the same one. Control desks would be able to send the same information to all lights and get the same color from each one. 4 Color Space Choice Explanation (informative) There are a number of ways to communicate color information in an unambiguous manner
39、from a control console to a luminaire. The simplest thing to standardize would be to agree a color space such as the familiar CIE 1931 x,y space used as the background plot in Figure 1. Although the CIE 1931 space has been superseded by newer spaces such as L*u*v* or L*a*b* which have better uniform
40、ity, it is still the most familiar space to most people. Any of these color spaces would work for us as a standard, they all cover the same underlying range of colors and they are all linear transformations of each other. Within that defined color space, we now need to define RGB primaries such that
41、 the familiar RGB system of color definition can be used. We dont want to reinvent the wheel. Kodak has already been through this ANSI E1.54, PLASA Standard for Color Communication in Entertainment Lighting 3 Photo/2014-5006r2 exercise and developed the ProPhoto color space as a suggested color spac
42、e for imaging and photographic use. Figure 2 Kodak ProPhoto Color Space ROMM RGB It has the following attributes: It is a larger space than any imaging device can achieve There is very little dead or unused space, so it offers the best use of available resolution No negative values of x or y It enco
43、mpasses 90% of all possible colors and 100% of all real world colors The ProPhoto space has been adopted as part of both ANSI/I3A IT10.7666:2003 and ISO 22028-2:2013 and is now commonly referred to as ROMM RGB (Reference Output Medium Metric RGB). We are adopting this same RGB color gamut for the PL
44、ASA standard. Most ANSI and ISO standards use the D50 white point, which has a CCT of 5003 K, roughly equivalent to daylight in some parts of the sky. It is therefore not an appropriate white point for our use. Instead, we adopt as the standard white point for entertainment luminaires the white ligh
45、t of a 3200 K black body emitter. 3200 K is commonly used as a standard white point for theatrical luminaires, gel swatch books, and lighting control consoles, and is a well-understood reference. 5 Color Math Examples (informative) 5.1 RGB Control The input is 3 values of 0 to 100% each for R (red),
46、 G (green) and B (blue). The output is a pair of CIE 1931 x,y Coordinates. ANSI E1.54, PLASA Standard for Color Communication in Entertainment Lighting 4 Photo/2014-5006r2 5.2 Convert PLASA RGB to CIE 1931 (x, y): The basic conversion uses a 3x3 transformation matrix derived from the PLASA RGB trian
47、gle and white point. = x Where, in this case, using our defined PLASA RGB color space and white point: = Thus: = x Worked example: Red Input = 79% Green Input = 58% Blue Input = 91% Convert to (X, Y, Z) = = Convert to CIE 1931 (x, y) x = x = = 0.438591 y = y = = 0.353038 Thus PLASA RGB values of (79
48、%, 58%, 91%) result unambiguously in a CIE 1931 x,y color coordinate of (0.438591, 0.353038) 5.2 HSI Control HSI (Hue, Saturation, Intensity) is directly related to RGB and white point so, once an RGB space is defined, so too is the corresponding HSI space. However, we need to add a few subsidiary d
49、efinitions to complete the picture. ANSI E1.54, PLASA Standard for Color Communication in Entertainment Lighting 5 Photo/2014-5006r2 Hue is an angular measurement that varies for 0 to 360. Clause 1.2 of this Standard defines the reference hue angles as: Hue of 0 = Full Red (RGB = 100,0,0) Hue of 120 = Full Green (RGB = 0,100,0) Hue of 240 = Full Blue (RGB = 0,0,100) To convert from H=Hue, S=Saturation to RGB we can use the following equations: If Hue is between 0 and 120 Degrees: R = (1 + S (cos(H)/(cos(60-H)/3 G = 1 R B B = (1 S)/3 If Hue
