3D Point-Cloud Encoding With Prediction-Specific Contexts

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Solution Overview

Problem

Existing methods for representing and compressing three-dimensional data, such as point clouds, face challenges in efficiently encoding and decoding large volumes of data due to the massive amount of data involved, necessitating improved coding efficiency.

Innovation Solution

A three-dimensional data encoding and decoding method that utilizes inter prediction and intra prediction to calculate residuals, employing different contexts for arithmetic encoding and decoding based on the prediction method, thereby improving encoding and decoding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If point cloud data is used to represent three-dimensional structures, then the shape and position information is preserved, but the data amount becomes massive requiring compression

Engineering Contradiction:

Improveposition information accuracyVSAvoiddata amount

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the point cloud data processing into multiple stages: prediction stage (using inter or intra prediction to generate predicted positions), residual calculation stage (computing differences between actual and predicted positions), and encoding stage (arithmetic encoding residuals with different contexts). This segmentation transforms the massive raw point cloud data into compressed representations while preserving position accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the parameter representation by transforming absolute position coordinates into residual values (differences from predicted positions). This parameter transformation significantly reduces the data amount while maintaining the ability to reconstruct accurate three-dimensional positions through decoding and addition of residuals to predicted values.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If a single context is used for arithmetic encoding residuals, then the encoding process is simple, but coding efficiency is reduced

Engineering Contradiction:

Improvecoding efficiencyVSAvoidencoding complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent applies different contexts (local quality settings) for arithmetic encoding based on the prediction method used. When inter prediction is used, one context is applied; when intra prediction is used, a different context is applied. This local differentiation of encoding parameters improves coding efficiency by adapting to the characteristics of each prediction method without requiring complex adaptive mechanisms.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12413781B2Three-dimensional data encoding method, three-dimensional data decoding method, three-dimensional data encoding device, and three-dimensional data decoding device

Publication Date: 2025.09.09 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA

AI summary

A three-dimensional data encoding method includes: calculating a predicted value of a position of a three-dimensional point according to one of inter prediction and intra prediction; calculating a residual between the predicted value and the position; arithmetic-encoding the residual using a first context when the predicted value is calculated according to the inter prediction; and arithmetic-encoding the residual using a second context different from the first context when the predicted value is calculated according to the intra prediction. The residual is expressed by third residual information indicating a bit count of the residual.