1、 Reference number ISO 26428-1:2008(E) ISO 2008INTERNATIONAL STANDARD ISO 26428-1 First edition 2008-09-01 Digital cinema (D-cinema) distribution master Part 1: Image characteristics Souche de la distribution du cinma numrique (cinma D) Partie 1: Caractristiques dimage ISO 26428-1:2008(E) PDF disclai
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5、ED DOCUMENT ISO 2008 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs memb
6、er body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2008 All rights reservedISO 26428-1:2008(E) ISO 2008 All rights reserved iii Foreword I
7、SO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical c
8、ommittee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electr
9、otechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the m
10、ember bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. ISO 26428-1 was prepared by the Society of Motion Picture and Television Engineers (as SMPTE 428-1-2006) and was adopted, under a special “fast-track procedure”,
11、by Technical Committee ISO/TC 36, Cinematography, in parallel with its approval by the ISO member bodies. ISO 26428 consists of the following parts, under the general title Digital cinema (D-cinema) distribution master: Part 1: Image characteristics Part 2: Audio characteristics Part 3: Audio channe
12、l mapping and channel labeling ISO 26428-1:2008(E) iv ISO 2008 All rights reservedIntroduction This International Standard comprises SMPTE 428-1-2006 and the following informative notes. Informative reference: The French national standard NF S27-100, Cinematography Electronic projection rooms of dig
13、ital cinema type, provides additional regional information. Image structures (see Clause 3): Within a national entity, anamorphic lenses may be required under certain circumstances in which masking limitations would not otherwise permit non-anamorphic projection. Digital cinema image aspect ratios (
14、see Annex A): An additional example aspect ratio of 1:66 to 1 would be achieved in: level 1 by using 3 584 horizontal pixels by 2 160 vertical pixels, and levels 2 and 3 by using 1 792 horizontal pixels by 1 080 vertical pixels. The International Organization for Standardization (ISO) draws attentio
15、n to the fact that it is claimed that compliance with this document may involve the use of a patent. ISO takes no position concerning the evidence, validity and scope of this patent right. The holder of this patent right has assured ISO that he is willing to negotiate licences under reasonable and n
16、on-discriminatory terms and conditions with applicants throughout the world. In this respect, the statement of the holder of this patent right is registered with ISO. Information may be obtained from: Eastman Kodak Company Intellectual Property Transactions 343 State Street Rochester, NY 14650 USA A
17、ttention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified above. ISO shall not be held responsible for identifying any or all such patent rights. ISO 26428-1:2008(E) ISO 2008 All rights reserved 1Table of contents
18、Foreword Introduction 1 Scope 2 Normative references 3 Image structures 4 Colorimetry Annex A Digital cinema image aspect ratios Annex B Dynamic range usage of the DCDM Annex C Bibliography Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized stand
19、ards 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 SMPTEs Technology Committees. P
20、articipation 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 Part XIII of its Administrative P
21、ractices. SMPTE Standard 428-1 was prepared by SMPTE Technology Committee DC28. Page 1 of 8 pages SMPTE 428-1-2006 SMPTE STANDARD D-Cinema Distribution Master Image Characteristics Copyright 2006 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914)
22、761-1100 Approved September 29, 2006 ISO 26428-1:2008(E) 2 ISO 2008 All rights reservedSMPTE 428-1-2006 Page 2 of 8 pages Introduction This standard describes the image characteristics of the Digital Cinema Distribution Master (DCDM). The image characteristics and parameters are not subject to any f
23、urther image processing prior to the compression process described elsewhere. In order for content creators to convert a Digital Source Master (DSM) into a Digital Cinema Distribution Master (DCDM), this standard will define all of the metrics required for the image structure of the DCDM. This DCDM
24、image structure may then be transported by being mapped into either real time interfaces or into file formats. In the process of creating theatrical releases, a Digital Source Master, or DSM, is produced from which many distribution elements are created, (e.g., Film Distribution Masters, Digital Cin
25、ema Distribution Masters (DCDM), Home Video Masters, Airline Version Masters and Broadcast Masters). It is not the goal of this specification to define the DSM. It is recognized that the DSM may consist of any color space, pixel matrix (spatial), frame rate (temporal), bit depth and many other metri
26、cs. This standard defines sets of operational levels, in terms of the maximum number of pixels, H pixel count and V pixel count. In combination with the frame rate this determines the operational level, 1-3 as defined in Table 1. ISO 26428-1:2008(E) ISO 2008 All rights reserved 3 SMPTE 428-1-2006 Pa
27、ge 3 of 8 pages 1 Scope This standard defines the uncompressed image characteristics for DCDM by specifying a pixel array, frame rate, pixel bit depth, and colorimetry. The DCDM image operational levels are defined by the maximum number of pixels and frame rate. 2 Normative references The following
28、standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibi
29、lity of applying the most recent edition of the standards indicated below. CIE Publication15:2004, Colorimetry SMPTE 431-1-2006, D-Cinema Quality Screen Luminance Level, Chromaticity and Uniformity 3 Image structures The pixel array shall use equally sampled tristimulus code values to represent each
30、 pixel. 1The maximum number of horizontal and vertical pixels shall be no greater than the limits of one of the operational levels as defined in Table 1 2 . The number of pixels shall extend to the maximum in either one or both of the horizontal and vertical directions of the defined operational lev
31、el. Table 1 DCDM operational levels Operational Level Maximum Horizontal Pixels Maximum Vertical Pixels Frames per Second 1 4096 2160 24 2 2048 1080 48 3 2048 1080 24 The pixel shall have an aspect ratio of 1:1. No anamorphic or other geometric distortions of the image data shall be permitted For op
32、erational level 1, the number of horizontal and vertical pixels shall be evenly divisible by four. For operational levels 2 and 3, the number of horizontal and vertical pixels shall be evenly divisible by two. 3.1 Pixel orientation and numbering The pixel orientation shall flow from left to right an
33、d top to bottom of the pixel array. The horizontal and vertical pixel count shall begin with 0. This is to mean that the top left pixel of the pixel array shall be notated as (0, 0). 1The pixel array is the set of pixels that are intended to be displayed on the cinema screen. 2Common film aspect rat
34、ios, unlike the native aspect ratio of the image boundaries shown in Table 1, shall be accommodated. Some examples of these are provided in the informative Annex A. ISO 26428-1:2008(E) 4 ISO 2008 All rights reservedSMPTE 428-1-2006 Page 4 of 8 pages 4 Colorimetry The color encoding of the Digital Ci
35、nema Distribution Master (DCDM) embodies a device-independent, XYZ color space as described in CIE Publication 15:2004, Colorimetry, 3rd Edition. Because the DCDM incorporates all of the creative color decisions made in the mastering process, and these decisions are made on a calibrated projector in
36、 a controlled mastering room, it is by definition an output-referenced image state. The picture colorimetry is defined for its intended display on the cinema screen. 4.1 DCDM encoding primaries The DCDM shall use the CIE Publication15:2004, (x,y coordinates) to describe the color primaries X, Y, and
37、 Z as a gamut container. 4.2 Pixel bit depth The pixel bit depth for each code value for a color component shall be 12 bits. 4.3 Transfer function The CIE XYZ 3tristimulus values shall each be normalized with a constant that sets the Y tristimulus value equal to 1.0 for the reference luminance (L) w
38、here both X and Z values are multiplied by the same constant. 4With this specification of the color, the following equations define the encoding transfer function 5 , where X, Y, Z are the tristimulus values above black6 . = 6 . 2 1 37 . 52 * * 4095 X L INT CV X = 6 . 2 1 37 . 52 * * 4095 Y L INT CV
39、 Y = 6 . 2 1 37 . 52 * * 4095 Z L INT CV Z3XYZ are the linear tristimulus values and are linear with light. XYZ are the symbols used in place of CV X, CV Y, and CV Z. 4The peak luminance as shown in the transfer function equation is 52.37 cd/m 2. The extra headroom is reserved to accommodate a range
40、 of white points including D 55 , D 61and D 65 , while still supporting the reference luminance (L) of 48 cd/m 2 as specified in SMPTE 431-1,Table 5.2 for Digital Cinema-Screen Luminance Level, Chromaticity and Uniformity. 5The INT operator returns the value of 0 for fractional parts in the range of
41、 0 to 0.4999 and +1 for fractional parts in the range 0.5 to 0.9999, i.e. it rounds up fractions above 0.5. 6This equation specifies luminance relative to the screen black level of the mastering environment (the projectors response to a zero code value 0,0,0 input signal plus the operating ambient l
42、ight of the room). Because tristimulus values are additive, the absolute luminance of the image seen can be found by adding the XYZ of the content to the XYZ of the black. ISO 26428-1:2008(E) ISO 2008 All rights reserved 5 SMPTE 428-1-2006 Page 5 of 8 pages CV X : Code Value of X CV Y : Code Value o
43、f Y CV Z : Code Value of Z L: Reference Luminance INT: Integer operator ISO 26428-1:2008(E) 6 ISO 2008 All rights reservedSMPTE 428-1-2006 Page 6 of 8 pages Annex A (informative) Digital cinema image aspect ratios Some examples of the accommodation of images of various aspect ratios are shown in Tab
44、le A.1. Where: AR = the aspect ratio of the image (ratio of width to height, expressed as a decimal.) Ph = total number of horizontal pixels in image Pv = total number of vertical pixels in image Table A.1 Example image aspect ratios Level Ph Pv AR 1 4096 1716 2.39:1 1 3996 2160 1.85:1 2&3 2048 858
45、2.39:1 2&3 1998 1080 1.85:1NOTE The Ph and Pv values must comply with the rules established in 3. ISO 26428-1:2008(E) ISO 2008 All rights reserved 7 SMPTE 428-1-2006 Page 7 of 8 pages Annex B (informative) Dynamic range usage of the DCDM The DCDM image characteristic specifies 12 bits resolution for
46、 each pixel and permits the range of values from 0 to 4095 (decimal). The 12-bit resolution is specified after a gamma transfer characteristic has been applied, thus the 12 bit digital samples represent the optical amplitude in a non-linear manner. This has a particular impact around low amplitude l
47、evels. B.1 Black and white levels SMPTE RP 431-2 defines the calibration white point of the Reference projector as having x y Y values of 0.314, 0.351, 48.00. The XYZ tristimulus values that are associated with these x y Y values are: X=42.94, Y=48.00, Z=45.82 Although the DCDM encoding is defined f
48、or XYZ above black, the white is so far above black that the black can be ignored for the white calculations. From the DCDM encoding equations, the code values for this white point are: C V x= 3794, CV y= 3960, CV z= 3890. None of these values exceed the maximum value of 4095 and the headroom for th
49、e value 3960 is 135 code values. The minimum DCDM code value allowed is 0. Because the DCDM encoding is defined for XYZ above black, the set of DCDM code values CVX = 0, CVY=0, and CVZ = 0 defines a luminance above black of 0, which means theater black. Assume a projector and theater have a 2000:1 or a 4000:1 contrast ratio. For a 2000:1 contrast ratio the delta XYZ values above bla
