Point Cloud Geometry Encoding With Spherical Inter-Frame Prediction

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Solution Overview

Problem

Existing technologies face challenges in efficiently processing and transmitting large amounts of point cloud data, particularly in terms of latency, encoding/decoding complexity, and compression efficiency, especially for applications like virtual reality, augmented reality, and self-driving services.

Innovation Solution

A method and apparatus for point cloud data transmission and reception that involves encoding geometry data into a spherical coordinate system, performing inter-frame prediction, and compressing data based on similarity between frames, using a point cloud data transmission device with a geometry encoder and attribute encoder to transform and compress data, and a reception method that decodes and renders the data in a Cartesian coordinate system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If point cloud data is transmitted using traditional Cartesian coordinate systems without inter-frame prediction, then the encoding process is simple, but compression efficiency is poor and data volume is large

Engineering Contradiction:
Improvecompression efficiencyVSAvoidencoding complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent transforms the coordinate system from Cartesian (x, y, z) to spherical (range, azimuth, elevation) to better represent point cloud data geometry. This parameter change enables more effective prediction of adjacent frame points, significantly improving compression efficiency by reducing redundant information while maintaining manageable encoding complexity through systematic transformation procedures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs coordinate transformation from Cartesian to spherical coordinate system before compression encoding. This preliminary action prepares the data in a format that facilitates inter-frame prediction, allowing the system to exploit temporal redundancy more effectively and achieve better compression ratios without substantially increasing overall system complexity.

Inventive Principle:
Principle #10Preliminary action

2Loss of information

If inter-frame prediction is performed on raw Cartesian coordinate data, then compression efficiency improves, but processing time increases causing latency

Engineering Contradiction:
Improvecompression ratioVSAvoidprocessing latency
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

By transforming to spherical coordinate system, the patent reorganizes data parameters to match the natural geometry of point cloud surfaces. This enables more accurate prediction of adjacent frame points with fewer computational operations, improving compression ratio while actually reducing processing time compared to operating on raw Cartesian coordinates.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If coordinate transformation and inter-frame prediction are applied to all point cloud data, then compression efficiency is maximized, but encoding and decoding complexity increases

Engineering Contradiction:
Improvecompression efficiencyVSAvoidencoding/decoding complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The systematic transformation to spherical coordinate system provides a structured approach that, while adding a transformation step, simplifies subsequent prediction operations. The regular mathematical relationships in spherical coordinates enable efficient algorithms that balance compression efficiency gains against the added encoding/decoding complexity, achieving optimal trade-off through standardized processing pipelines.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS12537978B2Point cloud data transmission device, point cloud data transmission method, point cloud data reception device, and point cloud data reception method
Publication Date: 2026.01.27 LG ELECTRONICS INC
  • US12537978B2 patent drawing
  • US12537978B2 patent drawing
  • US12537978B2 patent drawing

AI summary

A point cloud data transmission method according to embodiments comprises the steps of: encoding geometry data of point cloud data; encoding attribute data of the point cloud data on the basis of the geometry data; and transmitting the encoded geometry data, the encoded attribute data, and signaling data, wherein the step of encoding the geometry data may comprise the steps of: converting coordinates of the geometry data from a first coordinate system to a second coordinate system; and compressing the geometry data by performing prediction between neighboring frames on the second coordinate system.