Point Cloud Decoding Using Hierarchical Occupancy Prediction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing point cloud encoding and decoding technologies, such as those using the octree method, fail to improve compression performance for sparse point clouds measured by LiDAR, despite achieving improvements for dense point clouds.

Innovation Solution

A point cloud decoding device and method that predicts occupancy information of child nodes using the occupancy information of child hierarchical nodes, incorporating scanning range and interval data from LiDAR sensors to enhance intra prediction accuracy and compression performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If occupancy information of 26 parent hierarchical nodes is referred to for intra prediction, then compression performance is improved for dense point clouds, but processing time increases and no effect is achieved for sparse point clouds

Engineering Contradiction:
Improvecompression performanceVSAvoidprocessing time
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

The patent applies local quality by differentiating the prediction approach based on point cloud density. For sparse regions, it uses a simplified method referring to fewer child hierarchical nodes, while for dense regions, it can utilize more nodes. This localized adaptation optimizes processing time for sparse point clouds while maintaining compression performance where needed.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the prediction process into different hierarchical levels. Instead of uniformly referring to 26 parent hierarchical nodes for all child nodes, it performs prediction at the child hierarchical node level using a limited set of occupied child hierarchical nodes, thereby reducing the overall processing burden while maintaining effective compression.

Inventive Principle:
Principle #1Segmentation

2Loss of information

If occupancy information of 26 parent hierarchical nodes is referred to for intra prediction, then compression performance is improved for dense point clouds, but device complexity increases

Engineering Contradiction:
Improvecompression performanceVSAvoidprediction process complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent simplifies the prediction process by applying local quality - using a focused, localized approach that refers to only occupied child hierarchical nodes rather than all 26 parent hierarchical nodes. This reduces device complexity while maintaining compression effectiveness for the specific characteristics of sparse point clouds.

Inventive Principle:
Principle #3Local quality

3Loss of time

If the number of parent hierarchical nodes referred to is reduced to seven, then processing time is reduced, but compression performance deteriorates for dense point clouds

Engineering Contradiction:
Improveprocessing timeVSAvoidcompression performance
Core Design Contradiction:
Loss of timeVSLoss of information

Solution Approach 1:

The patent introduces dynamics by adaptively selecting the number of child hierarchical nodes to refer to based on the actual occupancy pattern. Rather than fixing the number at seven, it dynamically adjusts by referring to occupied child hierarchical nodes, which can be fewer than seven in sparse regions (reducing processing time) while potentially utilizing more nodes in dense regions (maintaining compression performance).

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of node reference from a fixed count (seven) to a dynamic count based on occupancy status. This parameter change allows the system to optimize between processing time and compression performance by adapting to the actual data characteristics rather than using a static configuration.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20240212219A1Point cloud decoding device, point cloud decoding method, and program
Publication Date: 2024.06.27 KDDI CORP
  • US20240212219A1 patent drawing
  • US20240212219A1 patent drawing
  • US20240212219A1 patent drawing

AI summary

A point cloud decoding device (200) according to the present invention including a circuit, wherein the circuit: stores occupancy information of a child hierarchical node indicating whether or not the child hierarchical node is occupied; and predicts occupancy information of a child node indicating whether or not the child node is occupied using the occupancy information of the child hierarchical node.