ISO IEC 23091-2 pdf – Information technology — Coding- independent code points — Part 2: Video
1Scope
This document defines various code points and fields that establish properties of a video (or still image)representation and are independent of the compression encoding and bit rate. These properties candescribe the appropriate interpretation of decoded data or can, similarly, describe the characteristicsof such a signal before the signal is compressed by an encoder that is suitable for compressing such aninput signal.
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies.Forundated references, the latest edition of the referenced document (including any amendments) applies.ISO/CIE 11664-1, Colorimetry — Part 1: CIE standard colorimetric observers
3Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:- ISo Online browsing platform: available at https://www.iso .org/obp
—IEC Electropedia: available at https://www.electropedia .org/3.1
bottom field
assembly of the odd-numbered rows of samples of the components (3.3) of a video frame using anumbering of rows that starts with row number 0 as the top row
3.2
chroma
sample array or single sample representing one of the two colour difference signals related to theprimary colours, represented by the symbols Cb and Cr
Note 1 to entry: The term “chroma” is used rather than “chrominance” in order to avoid the implication of the useof linear light transfer characteristics that is often associated with “chrominance”.
3.3
component
array or single sample from one of the three arrays [luma (3.4) and two chroma (3.2)] that composea picture (3.5) in 4:2:0，4:2:2,or 4:4:4 colour format or the array or a single sample of the array thatcompose a picture in monochrome format
3.4luma
sample array or single sample representing the monochrome signal related to the primary colours,represented by the symbol or subscript Y or L
Note 1 to entry: The term “luma” is used rather than “luminance” in order to avoid the implication of the use oflinear light transfer characteristics that is often associated with “luminance”. The symbol L is sometimes usedinstead of the symbol Y to avoid confusion with the symbol y as used for vertical location.
3.5
picture
array of luma (3.4) samples in monochrome format or array of luma samples and two correspondingarrays of chroma (3.2) samples in 4:2:0,4:2:2, and 4:4:4 colour format
3.6
reserved
values of a particular code point that are for future use by ITU-T | ISO/IEC
Note 1 to entry: These values shall not be used in identifiers conforming to this edition of this document.lt is possible they will be used in a manner yet to be specified in some future extensions of this document byITU-T [ ISO/IEC.
3.7
top field
assembly of the even-numbered rows of samples of a video frame using a numbering of rows that startswith row number 0 as the top row
3.8
unspecified
values of a particular code point that have no specified meaning in this edition of this document andwill not have a specified meaning in the future as an integral part of future editions of this document
4Abbreviated terms
LSBleast significant bitMSBmost significant bit
5 conventions
NOTE The mathematical operators used in this document are similar to those used in the C programminglanguage.However,integer division and arithmetic shift operations are specifically defined. Numbering andcounting conventions generally begin from 0.
5.1Arithmetic operators
addition
subtraction (as a two-argument operator) or negation (as a unary prefix operator)multiplication, including matrix multiplication
exponentiation, x to the power of y (in other contexts,such notation may be used for super-
scripting not intended for interpretation as exponentiation)
5.2Bit-wise operators bit-wise “and”(when operating on integer arguments, operates on a two’s complementrepresentation of the integer value; when operating on a binary argument that contains fewer & bits than another argument, the shorter argument is extended by adding more significantbits equal to 0)