ISO/IEC INTERNATIONAL STANDARD 23090-9 First edition 2023-03 Information technology Coded representation of immersive media - Part 9: Geometry-based point cloud compression Technologies de Il'information -Représentation codée de media immersifs- Partie 9: Compression des nuages de points basee sur la geometrie Referencenumber IEC IS0/IEC 23090-9:2023(E) Is 4 @IS0/IEC2023 IS0/IEC23090-9:2023(E) COPYRIGHTPROTECTEDDOCUMENT @IS0/IEC2023 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or IsO's member body in the country of the requester. ISo copyright office CP401·Ch.deBlandonnet8 CH-1214 Vernier,Geneva Phone: +41 22 749 01 11 Email:copyright@iso.org Website: www.iso.org Published in Switzerland ii IS0/IEC2023-All rights reserved IS0/IEC23090-9:2023(E) Contents Page Foreword .vii Introduction .vii 1 Scope. .1 2 Normative references .1 3 Terms and definitions. .1 3.1 General terms. 1 3.2 Terms relatedtohigh-level syntax and entropy coding 3 3.3 Terms related to tree structure 6 Terms related togeometrycoding 7 3.4 3.5 Terms related to attribute coding 7 4 Abbreviatedterms .8 5 Conventions. .9 5.1 General. 9 5.2 Symbolic names 9 5.3 Numericalrepresentation 10 5.4 Arithmetic operators. 10 5.5 Logical operators. 10 5.6 Relational operators 10 Bit-wise operators. .11 5.7 5.8 Assignment operators 11 5.9 Range notation 11 5.10 Mathematical functions .12 5.10.1 General 12 5.10.2 IntAtan2 13 5.10.3 IntCos and IntSin 13 5.10.4 IntSqrt. 14 5.10.5 IntRecipSqrt 14 5.10.6 Div. 15 5.10.7 Morton .15 5.10.8 FromMorton 16 5.11 Order of operation precedence 16 5.12 Named expressions. 17 5.12.1 General .17 5.12.2 Scopeofanamedexpression. 18 5.12.3 18 Argumentsofnamedexpressions 5.12.4 Sub-expressions. 19 5.12.5Definitionswithmultiplestatements 19 5.12.6 Textual definitions. 19 5.13 Variables, syntax elementsand tables. 19 .20 6 Point cloud format and relationship to coded and output representations. 6.1 General format 20 6.2 Attributes 20 .20 6.2.1 General 6.2.2 Colour 20 .21 6.2.3 Opacity 6.2.4 .21 Reflectance 6.2.5 Normal vector 21 6.2.6 Material identifier 21 6.2.7 21 Frame number/index. User defined attributes 22 6.2.8 .22 6.3 Codec-derived attributes. .22 6.3.1 General iii ISO/IEC2023-Allrightsreserved