ISO/IEC TR 23008-14:2018 情報技術—異種環境での高効率コーディングとメディア配信—パート14：PQ転送特性を備えたHDR / WCG Y'CbCr 4：2：0ビデオの変換とコーディングの実践 | ページ 6

3.1

electro-optical transfer function

EOTF

function used in the post-decoding process to convert from a non-linear representation to a linear representation

3.2

full range

range in a fixed-point (integer) representation that spans the full range of values that could be expressed with that bit depth, such that, for 10-bit signals, black corresponds to code value 0 and peak white corresponds to code value 1023 for Y′

Note 1 to entry: As per the full range definition from Rec. ITU-R BT.2100.

3.3

inverse electro-optical transfer function

inverse EOTF

function used in the pre-encoding process to convert from a linear representation to a non-linear representation, computed as the inverse of the EOTF (3.1)

Note 1 to entry: In this document, the pre-encoding process is assumed to operate on HDR/WCG video content that has been prepared for a hypothetical reference viewing environment as shown in Figure 1. The content preparation step may contain processing such as applying an opto-optical transfer function (OOTF) (3.6) , in which the HDR/WCG video is converted from one linear representation (corresponding to the scene) to another linear representation (corresponding to the display). The OOTF has the role of applying a “rendering intent”. In systems where no such OOTF is applied in the content preparation step, the process of converting from a linear representation (corresponding to the scene) to a non-linear representation is typically called the opto-electrical transfer function (OETF) (3.5) .

3.4

narrow range

range in a fixed-point (integer) representation that does not span the full range (3.2) of values that could be expressed with that bit depth such that, for 10 bit representations, the range from 64 (black) to 940 (peak white) is used for Y′ and the range from 64 to 960 is used for Cb and Cr

Note 1 to entry: As per the narrow range definition from Rec. ITU-R BT.2100.

Note 2 to entry: Narrow range is, in some applications, called by synonyms such as: “limited range”, “video range”, “legal range”, “SMPTE range” or “standard range”.

3.5

opto-electrical transfer function

OETF

function that converts linear scene light into the video signal, typically within a camera

3.6

opto-optical transfer function

OOTF

function that maps relative scene linear light (typically the camera output signal) to display linear light (typically, the signal driving a mastering monitor)

3.7

random access point access unit

RAPAU

access unit in the bitstream containing an intra coded picture with the property that all pictures following the intra coded picture in output order can be correctly decoded without using any information preceding the random access point access unit in the bitstream

3.8

transfer function

function that can be EOTF (3.1) , inverse EOTF (3.3) , OETF (3.5) , inverse OETF, OOTF (3.6) , or inverse OOTF