ISO/IEC 23090-18:2024/Amd 2:2026

International
Standard
ISO/IEC 23090-18
First edition
Information technology — Coded
2024-01
representation of immersive
media —
AMENDMENT 2
2026-02
Part 18:
Carriage of geometry-based point
cloud compression data
AMENDMENT 2: Point reliability
indication and other improvements
Reference number
ISO/IEC 23090-18:2024/Amd. 2:2026(en) © ISO/IEC 2026

ISO/IEC 23090-18:2024/Amd. 2:2026(en)
© ISO/IEC 2026
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© ISO/IEC 2026 – All rights reserved
ii
ISO/IEC 23090-18:2024/Amd. 2:2026(en)
Foreword
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This document was prepared by Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee
SC 29, Coding of audio, picture, multimedia and hypermedia information.
A list of all parts in the ISO/IEC 23090 series can be found on the ISO and IEC websites.
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© ISO/IEC 2026 – All rights reserved
iii
ISO/IEC 23090-18:2024/Amd. 2:2026(en)
Information technology — Coded representation of
immersive media —
Part 18:
Carriage of geometry-based point cloud compression data
AMENDMENT 2: Point reliability indication and other
improvements
9.3
Add the following new subclauses after 9.2:

9.3   G-PCC confidence score
9.3.1  General
When a point cloud scene is acquired and transmitted in real-world conditions, scanning or transmission
failure can occur which degrade the acquired data, e.g. inaccuracy of points’ position, missing points. In
this case, the acquiring system can provide confidence score associated with different regions of the point
cloud data. Upon reception of this information, the application can process the point cloud data differently
whether the confidence score is high or low.
This subclause specifies signaling of confidence score information of points in a particular region in
ISOBMFF.
9.3.2   G-PCC confidence score structure
9.3.2.1  General
GPCCConfidenceScoreStruct provides the confidence score of points within a given 3D spatial region.
9.3.2.2  Syntax
aligned(8) class GPCCConfidenceScoreStruct() {
unsigned int(16) region_id;
unsigned int(1) bounding_box_present_flag;
unsigned int(1) dimensions_included_flag;
unsigned int(1) confidence_score_present_flag;
unsigned int(5) reserved;
if(bounding_box_present_flag) {
GPCCBoundingBox bounding_box(dimensions_included_flag);
}
if(confidence_score_present_flag) {
unsigned int(8) confidence_score;
}
}
9.3.2.3  Semantics
region_id is an identifier for the confidence score region.

© ISO/IEC 2026 – All rights reserved
ISO/IEC 23090-18:2024/Amd. 2:2026(en)
bounding_box_present_flag indicates the presence of bounding box information. For sync samples in
confidence score region metadata track this flag shall be set to 1. For non-sync samples in confidence
score region metadata track, this flag shall be set to 1 when the position or dimensions of this confidence
score region are updated with reference to the previous sync sample.
dimensions_included_flag indicates the presence of the bounding box with the scale field. For sync
samples in confidence score region metadata sample, this flag shall be set to 1. For non-sync samples
in confidence score region metadata sample, this flag shall only be set to 1 when the dimensions of this
confidence score region are updated with reference to the previous sync sample. This flag may be set to
1 only if bounding_box_present_flag is set to 1.
confidence_score_present_flag indicates the presence of the confidence score for the confidence score
region.
confidence_score indicates the degree of confidence in unit of 1/255 in the range of 0.0 to 1.0 for the data in
the confidence score region. A signaled value of 0 expresses a score of 0.0 which means the confidence
in the data in the confidence score region is the lowest. A signaled value of 255 expresses a score of 1.0
which means the confidence in the data in the confidence score region is the highest. An application
should take into account the confidence score when processing the data and deriving actions, results,
interpretations, etc… When not present, the confidence score is unknown.
9.3.3   Signalling of confidence score information
9.3.3.1   Definition
'gcsr'
Box Types:
Container: GPCCSampleEntry('gpe1', 'gpeg', 'gpc1', 'gpcg', 'gpeb', 'gpcb') or DynamicGPC
CConfidenceScoreSampleEntry
Mandatory: No
Quantity: Zero or one
The GPCCConfidenceScoreInfoBox provides information of one or more confidence scores.
When GPCCConfidenceScoreInfoBox is present in the sample entry of the G-PCC bitstream track, it provides
the static confidence score information of G-PCC bitstream carried in the track.
When GPCCConfidenceScoreInfoBox is present in the sample entry of the G-PCC geometry track, it indicates
the static confidence score information of G-PCC bitstream carried in the G-PCC geometry track and
associated G-PCC attribute tracks. It shall not be present in the sample entry of any G-PCC attribute tracks.
When GPCCConfidenceScoreInfoBox is present in the sample entry of the G-PCC tile base track, it provides
the static confidence score information of G-PCC bitstream carried in all G-PCC tile tracks. It shall not be
present in the sample entry of any G-PCC tile tracks.
9.3.3.2  Syntax
aligned(8) class GPCCConfidenceScoreInfoBox extends FullBox('gcsr', version=0, 0) {
unsigned int(16) num_regions;
for (int i=0; i < num_regions; i++) {
GPCCConfidenceScoreStruct score();
}
}
9.3.3.3  Semantics
num_regions indicate the number of confidence score structure presented in the box.
score provides the confidence score information.

© ISO/IEC 2026 – All rights reserved
ISO/IEC 23090-18:2024/Amd. 2:2026(en)
9.3.4  Sample entry
9.3.4.1  Syntax
aligned(8) class GPCCConfidenceScoreConfigurationStruct() {
bit(7) reserved=0;
unsigned int(1) dynamic_dimension_flag;
}
aligned(8) class DynamicGPCCConfidenceScoreSampleEntry extends MetaDataSampleEntry('gcdc') {
GPCCConfidenceScoreInfoBox info_box;
GPCCConfidenceScoreConfigurationStruct configuration;
}
9.3.4.2  Semantics
dynamic_dimension_flag equal to 0 specifies that the dimension of the 3D spatial region remains unchanged
in all samples referring to this sample entry. dynamic_dimension_flag equal to 1 specifies that the
dimension of the 3D spatial region is indicated in samples.
info_box indicates one or more initial 3D spatial region with the associated confidence score of the G-PCC
data.
configuration contains configuration related to the samples referring to this sample entry.

9.3.5  Sample format
9.3.5.1  General
A sample in the confidence score region timed metadata track shall be set as a sync sample or as a non-sync
sample. At least one sync sample shall be present in the confidence score region timed-metadata track.
Sync samples in the confidence score region timed metadata shall carry the dimension for all G-PCC
confidence score regions. In sync samples for all confidence score regions, the value of dimensions_included_
flag and bounding_box_present_flag shall be set to 1.
Non-sync samples in confidence score region timed metadata track shall signal only the updated confidence
score regions informati
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