ISO/TS 22028-5:2023 写真およびグラフィック テクノロジ — デジタル画像の保存、操作、および交換のための拡張カラー エンコーディング — Part 5: 静止画像の高ダイナミック レンジおよび広色域エンコーディング (HDR/WCG) | ページ 6

3.1

coding-independent code points for video signal type identification

CICP

metadata that describes the colour image characteristics of the associated picture

3.2

colour image encoding

digital encoding of the colour values for a digital image, including the specification of a colour space encoding, together with any information necessary to properly interpret the colour values such as the image state, the intended image viewing environment, and the reference medium

[SOURCE:ISO 22028-1:2016, 3.9, modified — Notes to entry were deleted.]

3.3

colour volume

space of all colours and intensities that a device or signal can reproduce or convey

[SOURCE:ISO/IEC TR 23091-4:2021, 3.6/ITU-T H.SUPPLEMENT 19]

3.4

content colour volume

CCV

metadata that describes the colour volume (colour primaries, white point, and luminance range) characteristics of the associated picture

3.5

content light level

CLL

metadata that describes the light level characteristics (maximum and average) of the associated picture

3.6

diffuse white

stimulus that an observer adapted to the displayed content in the viewing environment would judge to be neutral and to have a luminance factor of unity

3.7

display light

image values that result from applying the reference EOTF to the encoded image signal values

3.8

display viewing colorimetry

colorimetry appropriate for a targeted display with specified viewing conditions

Note 1 to entry: The display viewing colorimetry typically depends on the creative intent for the content.

3.9

display referred

image state associated with image data that represents the colour-space coordinates of the elements of an image that has undergone colour-rendering appropriate for a specified display and viewing conditions

3.10

electrical-electrical transfer function

EETF

transfer function that adjusts the electronic signal, e.g. to tone map it to a lower display range

3.11

electro-optical transfer function

EOTF

transfer function which converts the non-linear signal into display light

3.12

high dynamic range and wide colour gamut encoding

HDR/WCG encoding

Colour image encoding that can contain wider variations in brightness, with a dynamic range significantly higher than that of a standard dynamic range encoding, and a wider range of colours with more saturated colours than standard colour gamut encodings

3.13

high dynamic range image

HDR image

image that contains wider variations in brightness, with a dynamic range significantly higher than that of a standard dynamic range image

3.14

highlights

image pixels with colorimetric values higher than those of the reference diffuse white

3.15

image

data structure that contains pixels and image-related data

[SOURCE:ISO/IEC 12087-1:1995, 3.1.3]

3.16

mastering display

a display that is used or targeted for viewing while authoring the content

3.17

mastering display colour volume

MDCV

metadata that identifies the colour volume (the colour primaries, white point chromaticity, and luminance range) of a mastering display

[SOURCE:SMPTE ST 2086:2018]

3.18

nominal peak luminance

luminance resulting on a display from the specified encoding peak white signal level

Note 1 to entry: The peak white signal level is specified to be lower than the peak signal level for narrow range encodings.

3.19

nominal diffuse white luminance

display luminance a viewer would consider, on average, correspond to a perfectly reflecting diffuser in the scene when viewing the mastering display

3.20

opto-electronic transfer function

OETF

transfer function that converts scene light into non-linear signal values

3.21

opto-optical transfer function

OOTF

transfer function that converts scene light to display light

3.22

nominal diffuse white

diffuse white value typical for the content encoding that is assumed for general purposes, independent of specified content or other information about the actual diffuse white

3.23

scene light

image values that result from applying the inverse reference OETF to the encoded image signal values

3.24

transfer function

single variable, monotonic mathematical function applied individually to one or more colour channels

3.25

wide colour gamut

WCG

gamut that has saturated colour primaries and includes a broad range of saturated colours

Note 1 to entry: It is wider than a standard colour gamut such as sRGB.

Note 2 to entry: WCG encodings provide a means to encode images with more saturated colours than standard colour gamut encodings, to represent a wider range of colours and allow for better colour reproduction.