1、 Approved May 18, 2016 Copyright 2016 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 SMPTE ST 2094-1:2016 SMPTE STANDARD Dynamic Metadata for Color Volume Transform Core Components Page 1 of 15 pages Table of Contents Page Foreword .
2、3 Intellectual Property 3 Introduction . 3 1 Scope . 5 2 Conformance Notation . 5 3 Normative References . 5 4 Terms and Definitions 6 4.1 application. 6 4.2 application identifier 6 4.3 application version 6 4.4 color volume . 6 4.5 color volume transform . 6 4.6 dynamic metadata 6 4.7 High Dynamic
3、 Range System (HDR System) 6 4.8 image essence . 6 4.9 luminance . 6 4.10 matrix 6 4.11 maxRGB . 6 4.12 metadata group 7 4.13 metadata item . 7 4.14 metadata set . 7 4.15 pixel coordinate 7 4.16 processing window . 7 4.17 sampled function 7 4.18 Standard Dynamic Range System (SDR System) . 7 4.19 ta
4、rgeted system 7 4.20 two-input sampled function . 7 4.21 vector 7 4.22 Wide Color Gamut (WCG) 7 4.23 window 7 4.24 xy chromaticity coordinates . 7 SMPTE ST 2094-1:2016 Page 2 of 15 pages 5 Overview (Informative) 8 6 Metadata Set . 8 7 Application Identifier and Version 8 8 Time Interval 9 8.1 Introd
5、uction 9 8.2 Time Interval Start . 9 8.3 Time Interval Duration . 9 9 Processing Window . 9 9.1 Introduction 9 9.2 Upper Left Corner 9 9.3 Lower Right Corner . 9 9.4 Window Number 9 10 Targeted System Display 10 10.1 Introduction . 10 10.2 Targeted System Display Primaries . 10 10.3 Targeted System
6、Display White Point Chromaticity . 10 10.4 Targeted System Display Maximum Luminance 10 10.5 Targeted System Display Minimum Luminance . 10 11 Color Volume Transform . 10 12 Matrix Constraints . 10 12.1 Number of Rows . 10 12.2 Number of Columns 11 12.3 Indexing 11 12.4 Numerical Representation 11 1
7、3 Sampled Function Constraints 11 13.1 Introduction . 11 13.2 Uniqueness of Values . 11 13.3 , Pair Ordering . 11 13.4 Input Domain 11 13.5 Range . 11 13.6 Numerical Representation 11 13.7 Interpolation Between Samples 11 13.8 Default Sampled Function 12 14 Two-input Sampled Function Constraints . 1
8、2 14.1 Introduction . 12 14.2 Data Structure 12 14.3 Value Ordering . 12 14.4 Input Domain 12 14.5 Mapping between Sample Points and Input Values . 12 14.6 Range . 12 14.7 Numerical Representation 13 14.8 Interpolation Between Samples 13 Annex A Dynamic Metadata Usage in a Generalized Color Volume T
9、ransform Model (Informative) . 14 Annex B Bibliography (Informative) 15 SMPTE ST 2094-1:2016 Page 3 of 15 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United Sta
10、tes 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. Participation in these Committees is open to all with a bona fide interest in
11、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 its Standards Operations Manual. SMPTE ST 2094-1 was prepared by Technology Committee 10E. Intellectual Proper
12、ty 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 possibility that some of the elements of this document may be the subject of patent rights. SMPTE shall not be he
13、ld 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. When image essence mastered with High Dynamic Range (HDR) and Wider Color Gamut (WCG) is transformed for presentation on a
14、display having a smaller color volume such as a Standard Dynamic Range (SDR) display, the color volume transform process can be optimized through the use of content-dependent, dynamic color volume transform metadata rather than using only static display color volume metadata. As the image essence ch
15、aracteristics change from scene to scene, the optimal transform that best reproduces the content creators artistic intent can change. For example, the color volume transform parameters used for a very dark scene could be quite different from those used for a very bright scene. As an alternative to a
16、rchiving and managing multiple, transformed masters, one for each targeted system, the transforms can be represented as metadata synchronized with the images of the HDR master. The metadata is captured or generated as a part of the mastering process, during which images are creatively approved, and
17、later applied as color volume transforms to the HDR master, therefore enabling alternate output encodings in the distribution stage. Provisions are included for supporting different models of color volume transforms with associated metadata sets, herein called applications. Metadata sets from multip
18、le applications and for multiple targeted systems can coexist, but are individually applied to the HDR master to create one or more output signals. Operational details about use and selection of metadata sets are not part of this document. SMPTE ST 2094-1:2016 Page 4 of 15 pages Figure 1 shows an ex
19、ample workflow using content-dependent, dynamic color volume transform metadata. In this example, the solid arrows represent the flow of complete image data with or without metadata and the dashed arrows represent the flow of metadata and/or image data from which metadata can be extracted. Two appro
20、ved image versions are provided, one HDR master and one SDR rendition. Some applications use an actual SDR master. Other applications use an interactive SDR rendering, where, during a grading process, the colorist interactively changes a color volume transform while viewing the resulting image on an
21、 SDR display. Content-dependent, dynamic metadata is extracted from the approved versions. Mastering display metadata (such as the color volume and dynamic range) is obtained for the HDR and the SDR reference mastering displays. The metadata is carried (here marked as “+m“) with the HDR master conte
22、nt for distribution. On playout, the metadata is utilized to transform the HDR content to the color volume and dynamic range of the consumer display device. The metadata can be applied in the distribution facility for different output media, in a consumer playout device, in the consumer display, or
23、not at all, depending on the needs and capabilities of the distribution channel and consumer equipment. Figure 1 Example Dynamic Metadata Workflow SMPTE ST 2094-1:2016 Page 5 of 15 pages 1 Scope The SMPTE ST 2094 suite of documents define metadata for use in color volume transforms of content. The m
24、etadata are content-dependent and can vary scene-by-scene or image-by-image. The metadata are intended to transform High Dynamic Range and Wide Color Gamut (HDR/WCG) image essence for presentation on a display having a smaller color volume than that of the mastering display used for mastering the im
25、age essence. Multiple applications provide particular color volume transforms. This standard, a part of the 2094 suite, specifies common definitions, including a transform metadata set, and metadata parameters, for use by other parts of the 2094 suite. Other parts of the 2094 suite provide represent
26、ation for carriage and additional application-specific metadata parameters for color volume transforms. 2 Conformance Notation Normative text is text that describes elements of the design that are indispensable or contains the conformance language keywords: “shall“, “should“, or “may“. Informative t
27、ext is text that is potentially helpful to the user, but not indispensable, and can be removed, changed, or added editorially without affecting interoperability. Informative text does not contain any conformance keywords. All text in this document is, by default, normative, except: the Introduction,
28、 any section explicitly labeled as “Informative“ or individual paragraphs that start with “Note:” The keywords “shall“ and “shall not“ indicate requirements strictly to be followed in order to conform to the document and from which no deviation is permitted. The keywords, “should“ and “should not“ i
29、ndicate that, among several possibilities, one is recommended as particularly suitable, without mentioning or excluding others; or that a certain course of action is preferred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not
30、 prohibited. The keywords “may“ and “need not“ indicate courses of action permissible within the limits of the document. The keyword “reserved” indicates a provision that is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” an
31、d 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 provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not
32、 implement optional provisions (“may“) and need not implement them as described. Unless otherwise specified, the order of precedence of the types of normative information in this document shall be as follows: Normative prose shall be the authoritative definition; Tables shall be next; then formal la
33、nguages; then figures; and then any other language forms. 3 Normative Reference The following standard contains provisions which, through reference in this text, constitute provisions of this engineering document. At the time of publication, the edition indicated was valid. All standards are subject
34、 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 standard indicated below. ISO 11664-3:2012 / CIE S 014-3/E:2011, Colorimetry Part 3: CIE Tristimulus Values SMPTE ST 2094-1:2016 Page 6
35、of 15 pages 4 Terms and Definitions For the purposes of this document, the following terms and definitions apply. Terms are defined here for use in referencing documents throughout the SMPTE ST 2094 suite. 4.1 application document in the SMPTE ST 2094 suite that define metadata, usage constraints, a
36、nd additional parameters related to a color volume transform model 4.2 application identifier integer value identifying an application and its defining document in the SMPTE ST 2094 suite 4.3 application version integer value specifying the version of the identified application, as given in the appl
37、ications defining document 4.4 color volume solid in colorimetric space containing all possible colors a display can produce 4.5 color volume transform transform, mapping a coordinate in one color volume to a coordinate in another color volume 4.6 dynamic metadata metadata that can be different for
38、different portions of the image essence 4.7 High Dynamic Range System (HDR System) system specified and designed for capturing, processing, and reproducing a scene, conveying the full range of perceptible shadow and highlight detail, with sufficient precision and acceptable artifacts, including suff
39、icient separation of diffuse white and specular highlights 4.8 image essence ordered sequence of rectangular images of same dimensions that can be indexed and the first image has the index of zero Note: Image as defined here can be a field or a group of images. 4.9 luminance luminous intensity of a
40、surface in a given direction, divided by the projected area of the surface element as viewed from that direction in units of candela per square meter (cd/m2) 4.10 matrix two-dimensional array of numbers 4.11 maxRGB maximum of color component values R, G, B of a pixel SMPTE ST 2094-1:2016 Page 7 of 1
41、5 pages 4.12 metadata group named collection of metadata items or metadata groups 4.13 metadata item named value of a given type, along with an associated range of valid values of that type 4.14 metadata set collection of metadata items or metadata groups 4.15 pixel coordinate coordinate in a two-di
42、mensional Cartesian coordinate system having signed integer coordinates with coordinates increasing from left to right and coordinates increasing from top to bottom, and (0,0) representing the top-left pixel 4.16 processing window window for selecting image essence pixels for color volume transform
43、(see window) 4.17 sampled function function = () represented as a list of , input/output pairs 4.18 Standard Dynamic Range System (SDR System) system having a reference reproduction using a luminance range constrained by Recommendation ITU-R BT.2035 Section 3.2 for video applications, or SMPTE RP 43
44、1 for cinema applications 4.19 targeted system image reproduction system addressed by a color volume transform 4.20 two-input sampled function function = (, ) represented as a two-dimensional array of output values 4.21 vector ordered list of numbers 4.22 Wide Color Gamut (WCG) chromaticity gamut la
45、rger than the chromaticity gamut defined by Recommendation ITU-R BT.709 4.23 window axis-parallel rectangular region in pixel space specified by the pixel coordinates of two opposing corners, (, ) and (, ), and including all pixels with coordinates (, ), where , and 4.24 xy chromaticity coordinates
46、CIE 1931 chromaticity coordinates x and y, as specified in ISO 11664-3 SMPTE ST 2094-1:2016 Page 8 of 15 pages 5 Overview (Informative) This standard together with application-specific documents in the SMPTE ST 2094 suite defines metadata for color volume transforms. This document defines metadata g
47、roups, a core set of metadata items, and data structures. In application-specific documents, an application defines one or more application-specific metadata sets. A metadata set incorporates a time interval, a window, metadata describing the targeted system display and the color volume transform. M
48、etadata for a time interval define a portion of the image essence to be processed by a specified color volume transform. Metadata for a window define the part of an image to be processed by a specified color volume transform. Metadata for a targeted system display define key metadata items of the ta
49、rgeted system display for which the color volume transform metadata is intended. A receiver of the metadata can use the targeted system display metadata to select the metadata sets that are most applicable to the actual output device. A receiver of the metadata can use the targeted system display metadata to adjust the output of the color volume transform from the specified output d
