SMPTE ST 2094-10-2016 Dynamic Metadata for Color Volume Transform C Application #1.pdf

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 2094-10:2016 SMPTE STANDARD Dynamic Metadata for Color Volume Transform Application #1 Page 1 of 15 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 4.1 PQ-encoded maxRGB 4 4.2 selected pixels 4 5 Application Identification . 4 6 Color Volume Transform 4 6.1 maxRGB-based Tone Mapping 4 6.2 Offset, Gain and Gamma-based

3、Tone Mapping 5 6.3 Tone Mapping-based Chroma and Saturation Adjustment 6 6.4 Detail Management 6 7 Application Constraints . 7 7.1 Metadata Set 7 7.2 Processing Window Constraints . 8 Annex A Mapping of Application #1 to the Generalized Color Volume Transform Model (Informative) . 9 Annex B Parametr

4、ic Tone Mapping Method Description (Informative) . 10 B.1 Introduction. 10 B.2 Luminance Transform Curve 11 B.3 Example Transform Using RGB Color Components 12 Annex C Bibliography (Informative) . 15 SMPTE ST 2094-10:2016 Page 2 of 15 pages Foreword SMPTE (the Society of Motion Picture and Televisio

5、n Engineers) is an internationally-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 Guideli

6、nes, are prepared by 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

7、the rules given in its Standards Operations Manual. SMPTE ST 2094-10 was prepared by Technology Committee 10E. Intellectual Property SMPTE draws attention to the fact that it is claimed that compliance with this Standard may involve the use of one or more patents or other intellectual property right

8、s (collectively, “IPR“). The Society takes no position concerning the evidence, validity, or scope of this IPR. Each holder of claimed IPR has assured the Society that it is willing to License all IPR it owns, and any third party IPR it has the right to sublicense, that is essential to the implement

9、ation of this Standard to those (Members and non-Members alike) desiring to implement this Standard under reasonable terms and conditions, demonstrably free of discrimination. Each holder of claimed IPR has filed a statement to such effect with SMPTE. Information may be obtained from the Director, S

10、tandards 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 prohibited. The keywords “may“ and “need not“ indicate courses of action permissible within the limits of the document

11、. 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” and in addition indicates that the provision will never be defined in the future. A conformant implementation according t

12、o this document is one that includes all mandatory 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

13、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 languages; then figures; and then any other language forms. 3 Normative References The following standards contain provis

14、ions which, through reference in this text, constitute 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 possibi

15、lity of applying the most recent edition of the standards indicated below. SMPTE ST 2084:2014, High Dynamic Range Electro-Optical Transfer Function of Mastering Reference Displays SMPTE ST 2094-1:2016, Dynamic Metadata for Color Volume Transform Core Components SMPTE ST 2094-10:2016 Page 4 of 15 pag

16、es 4 Terms and Definitions For the purposes of this document, the terms and definitions given in SMPTE ST 2094-1 and the following apply. 4.1 PQ-encoded maxRGB maxRGB values as defined in SMPTE ST 2094-1 and encoded according to the Reference Inverse-EOTF specified in SMPTE ST 2084 4.2 selected pixe

17、ls pixels within a processing window as defined in SMPTE ST 2094-1 5 Application Identification The ApplicationIdentifier value shall be 1 and the ApplicationVersion value shall be 0 to identify this version of Application #1. These two values identify this document as the defining document for the

18、application-specific metadata specified in Section 7.1. 6 Color Volume Transform 6.1 maxRGB-based Tone Mapping 6.1.1 Introduction The color volume transform for Application #1 is based on parametric tone mapping. The minimum, average and maximum PQ-encoded maxRGB values are computed from the selecte

19、d pixels. These metadata items are computed characteristics of the associated image essence and are collected in the metadata group ImageCharacteristicsLayer. All remaining metadata items are manual adjustments to the color volume transform and are collected in the metadata group ManualAdjustmentLay

20、er. 6.1.2 Reduced Pixel Set The reduced pixel set is the half resolution version of the selected pixels and is used for calculating the minimum, average and maximum PQ-encoded maxRGB value. The reduced pixel set is sampled from the selected pixels throughout all image essence associated with a metad

21、ata set. The reduced pixel set is calculated as follows: Starting at the upper-left corner (, ) of the ProcessingWindow, the ProcessingWindow shall be partitioned into non-overlapping sample areas, each comprising 2x2 pixels. A component-by-component average shall be calculated for the pixels in eac

22、h sample area. If a sample area falls partly outside the ProcessingWindow, only the (1 or 2) pixels that are in the intersection of the sample area and the ProcessingWindow shall be used in calculating the average. The reduced pixel set shall be the set of computed averages. SMPTE ST 2094-10:2016 Pa

23、ge 5 of 15 pages 6.1.3 Minimum PQ-encoded maxRGB The MinimumPqencodedMaxrgb shall be the lowest PQ-encoded maxRGB value of the reduced pixel set. Its value shall be a number in the range 0, 1 and in multiples of 0.00001. 6.1.4 Average PQ-encoded maxRGB The AveragePqencodedMaxrgb shall be the average

24、 of the PQ-encoded maxRGB values of the reduced pixel set. Its value shall be a number in the range 0, 1 and in multiples of 0.00001. 6.1.5 Maximum PQ-encoded maxRGB The MaximumPqencodedMaxrgb shall be the highest PQ-encoded maxRGB value of the reduced pixel set. Its value shall be a number in the r

25、ange 0, 1 and in multiples of 0.00001. 6.1.6 Minimum PQ-encoded maxRGB Offset The MinimumPqencodedMaxrgbOffset shall be an offset in the same unit as MinimumPqencodedMaxrgb to be added to the MinimumPqencodedMaxrgb value. Its value shall be a number in the range -0.5, 0.5 and in multiples of 0.00001

26、. Its default value shall be 0.0. 6.1.7 Average PQ-encoded maxRGB Offset The AveragePqencodedMaxrgbOffset shall be an offset in the same unit as AveragePqencodedMaxrgb to be added to the AveragePqencodedMaxrgb value. Its value shall be a number in the range -0.5, 0.5 and in multiples of 0.00001. Its

27、 default value shall be 0.0. 6.1.8 Maximum PQ-encoded maxRGB Offset The MaximumPqencodedMaxrgbOffset shall be an offset in the same unit as MaximumPqencodedMaxrgb to be added to the MaximumPqencodedMaxrgb value. The value shall be a number in the range -0.5, 0.5 and in multiples of 0.00001. Its defa

28、ult value shall be 0.0. 6.1.9 Metadata Values Constraints The metadata items defined in Sections 6.1.3 through 6.1.8 shall meet the following condition: 0 (MinimumPqencodedMaxrgb + MinimumPqencodedMaxrgbOffset ) (AveragePqencodedMaxrgb + AveragePqencodedMaxrgbOffset ) (MaximumPqencodedMaxrgb + Maxim

29、umPqencodedMaxrgbOffset) 1 6.2 Offset, Gain and Gamma-based Tone Mapping 6.2.1 Introduction The tone mapping offset, gain and gamma values shall be applied according to the equation: = (0,( )+),1) (1) where: SMPTE ST 2094-10:2016 Page 6 of 15 pages = output value = input value = value of Tone Mappin

30、g Gain = value of Tone Mapping Offset = value of Tone Mapping Gamma 6.2.2 Tone Mapping Offset The ToneMappingOffset shall be the Tone Mapping Offset defined in equation (1). Its value shall be in the range -0.5, 0.5 and in multiples of 0.00001. Its default value shall be 0.0. 6.2.3 Tone Mapping Gain

31、 The ToneMappingGain shall be the Tone Mapping Gain defined in equation (1). Its value shall be in the range 0.5, 1.5 and in multiples of 0.0001. Its default value shall be 1.0. 6.2.4 Tone Mapping Gamma The ToneMappingGamma shall be the Tone Mapping Gamma defined in equation (1). Its value shall be

32、in the range 0.5, 1.5 and in multiples of 0.001. Its default value shall be 1.0. 6.3 Tone Mapping-based Chroma and Saturation Adjustment 6.3.1 Chroma Compensation Weight The ChromaCompensationWeight shall be an amount of chroma adjustment. The adjustment depends on the luminance and saturation input

33、s of the tone mapping transform. Its value shall be in the range -0.5, 0.5 and in multiples of 0.0001. Its default value shall be 0.0. 6.3.2 Saturation Gain The SaturationGain shall be an amount of saturation adjustment. The adjustment depends on the luminance and chroma inputs of the tone mapping t

34、ransform. Its value shall be in the range -0.5, 0.5 and in multiples of 0.0001. Its default value shall be 0.0. 6.4 Detail Management 6.4.1 Introduction Detail management is a processing block that controls the appearance of image details after tone mapping. The metadata item specified in Section 6.

35、4.2, Tone Detail Factor, is independent of the processing method. 6.4.2 Tone Detail Factor The ToneDetailFactor shall control the contribution of the detail management function to the tone mapping result. Its value shall be in the range 0, 1 and in multiples of 0.001. Its default value shall be 0.0.

36、 Note: An example use of the tone detail factor is an image peaking operation, where ToneDetailFactor specifies no contribution at 0.0 and full contribution at 1.0. SMPTE ST 2094-10:2016 Page 7 of 15 pages 7 Application Constraints 7.1 Metadata Set A metadata set shall contain exactly one of each of

37、 the following: ApplicationIdentifier (= 1) ApplicationVersion (= 0) TimeInterval which shall contain exactly one of all metadata items defined in SMPTE ST 2094-1 TimeIntervalStart TimeIntervalDuration ProcessingWindow which shall contain exactly one of all metadata items defined in SMPTE ST 2094-1

38、UpperLeftCorner LowerRightCorner WindowNumber TargetedSystemDisplay which shall contain exactly one of all metadata items defined in SMPTE ST 2094-1 TargetedSystemDisplayPrimaries TargetedSystemDisplayWhitePointChromaticity TargetedSystemDisplayMaximumLuminance TargetedSystemDisplayMinimumLuminance

39、ColorVolumeTransform metadata items defined in this document (Section 6) ImageCharacteristicsLayer, which shall contain exactly one of each of the following named items: MinimumPqencodedMaxrgb AveragePqencodedMaxrgb MaximumPqencodedMaxrgb ManualAdjustmentLayer, which may contain any combination havi

40、ng zero or one of each of the following named items: MinimumPqencodedMaxrgbOffset AveragePqencodedMaxrgbOffset MaximumPqencodedMaxrgbOffset ToneMappingOffset ToneMappingGain ToneMappingGamma ChromaCompensationWeight SaturationGain ToneDetailFactor SMPTE ST 2094-10:2016 Page 8 of 15 pages 7.2 Process

41、ing Window Constraints If multiple metadata sets are defined for the same pixel of an image and with the same TargetedSystemDisplay metadata values, the set with the highest WindowNumber shall define the color volume transform associated with the pixel. SMPTE ST 2094-10:2016 Page 9 of 15 pages Annex

42、 A Mapping of Application #1 to the Generalized Color Volume Transform Model (Informative) The diagram in Figure A.1 describes Application #1 Parametric Tone Mapping based color volume transform in the framework of the generalized Color Volume Transform Model described in SMPTE ST 2094-1. The proces

43、sing blocks applied are Tone Mapping, Gamut Adjustment and Detail Management. Figure A.1 Processing blocks used by Application #1 SMPTE ST 2094-10:2016 Page 10 of 15 pages Annex B Parametric Tone Mapping Method Description (Informative) B.1 Introduction The design requirements for Application #1 are

44、 fulfilled by adopting an analytically defined sigmoidal curve specified by three control parameters as depicted in Figure B.1. When applied in units of absolute display light output, the dependency of targeted system display luminance in logarithmic scale as a function of the mastering display lumi

45、nance in logarithmic scale exhibits a linear portion with a gentle rise from minimum (toe) targeted system display luminances and a roll off towards maximum (shoulder) targeted system display luminances. The slope of the linear portion as well as the shapes of the toe and shoulder region are control

46、led by the three control points. In Application #1, the initial values of the control points, prior to any adjustment, are algorithmically computed from the input pixel values, and are carried as metadata items MinimumPqencodedMaxrgb, AveragePqencodedMaxrgb and MaximumPqencodedMaxrgb. Figure B.1 Ton

47、e mapping curve for Application #1 The curve in Figure B.1 can be adjusted manually by offsetting the minimum, average and maximum control points by using the parameters specified in MinimumPqencodedMaxrgbOffset, AveragePqencodedMaxrgbOffset and MaximumPqencodedMaxrgbOffset, respectively. To provide

48、 further manual control for the mapping curve, Application #1 also respects the common color correction technique of offsetting the minimum targeted system display output level, applying a gain factor for the entire luminance range and applying a gamma function affecting the mid-tones. These paramet

49、ers are specified by ToneMappingOffset, ToneMappingGain and ToneMappingGamma. Target adaptation level Adaptation point Source adaptation level SMPTE ST 2094-10:2016 Page 11 of 15 pages The slope of the tone mapping curve affects image saturation. A SaturationGain control parameter provides a saturation boost or diminution, and a ChromaCompensationWeight control parameter provides an overall chrominance compensation weighting factor for the