Part-Based Point Cloud Graphs for Unseen-Domain Classification

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Solution Overview

Problem

Existing point cloud classification models struggle with domain generalization, failing to accurately classify features in unseen and unlabeled target domains due to variations in data acquisition processes, often treating the point cloud as a monolithic entity and neglecting the intricate complexities and nuances of object structures.

Innovation Solution

The method involves segmenting the point cloud into meaningful parts using unsupervised part decomposition and inducing a graph structure representation, encapsulating structural relationships between these parts, and using graph encoder convolutional neural networks to derive a point cloud representation for improved classification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If point cloud classification models are trained on labelled source domain data, then classification accuracy improves on training data, but the models fail to generalize to unseen target domains with different data acquisition processes

Engineering Contradiction:
Improveclassification accuracyVSAvoiddomain generalization
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The point cloud is divided into multiple meaningful parts through unsupervised part decomposition, where each part is processed independently to extract local features. This segmentation allows the model to capture fine-grained structural information that is more robust to domain variations, resolving the contradiction between achieving high classification accuracy and maintaining domain generalization capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transforms the point cloud data into graph structure embeddings that capture structural relationships between parts. By changing the representation parameters from raw point coordinates to graph-based structural features, the model achieves better domain invariance while maintaining classification accuracy, as structural relationships are more consistent across different domains than raw geometric data.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the point cloud is treated as a monolithic entity, then the processing is simpler, but the intricate complexities and nuances of object structures are neglected

Engineering Contradiction:
Improveprocessing complexityVSAvoidstructural information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The point cloud is decomposed into meaningful parts that preserve structural information. Each part is then represented as a node in a graph structure, maintaining the hierarchical and spatial relationships between different components. This segmentation approach prevents information loss while managing complexity through modular processing of individual parts rather than the entire point cloud at once.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a graph structure dimension that captures relationships between point cloud parts. By transforming from a flat point cloud representation to a hierarchical graph structure with nodes and edges, the model preserves structural nuances while organizing information in a computationally manageable format that maintains both detail and overall structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If graph structure representation is induced to capture structural relationships, then classification accuracy improves, but the computational complexity increases

Engineering Contradiction:
Improveclassification accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The graph structure is built by first segmenting the point cloud into meaningful parts, then creating graph nodes and edges based on these segments. This hierarchical segmentation reduces the overall graph size compared to creating a complete graph of all points, thereby reducing computational complexity while still capturing essential structural relationships for improved classification accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts only the essential structural relationships needed for classification by selectively creating graph edges between relevant parts. Rather than computing all possible relationships, the method extracts and processes only the most significant structural connections, reducing computational burden while maintaining the accuracy benefits of graph-based representation.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4625345A1Point cloud classification
Publication Date: 2025.10.01 FUJITSU LTD
  • EP4625345A1 patent drawingFigure 1
  • EP4625345A1 patent drawingFigure 2
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AI summary

A computer-implemented method of performing point cloud classification comprising: selecting a point cloud for classification; obtaining a plurality of subsets of the selected point cloud associated with a plurality of parts of the selected point cloud; obtaining a graph structure representation of the subsets, the graph structure representation comprising nodes associated with each subset and one or more edges connecting the nodes; obtaining a graph structure embedding encapsulating structural relationships between the subsets, comprising inputting the graph structure representation into a graph encoder convolutional neural network; deriving a point cloud representation from the graph structure embedding; and classifying the point cloud representation, comprising inputting the point cloud representation into a classification neural network to obtain a classification of the selected point cloud.