3D Point Cloud Segmentation Training with Image Alignment Constraints

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Solution Overview

Problem

The inaccuracy of pseudo-labels generated by existing weak supervised point cloud semantic segmentation methods based on scene classification supervision signals leads to inaccurate semantic segmentation results in three-dimensional point clouds.

Innovation Solution

A training method for a three-dimensional point cloud processing model that incorporates an alignment constraint loss and classification loss by aligning three-dimensional point cloud data with two-dimensional image data using feature, global, and semantic matching, and training the model with a weighted result of these losses to improve labeling accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If weak supervised point cloud semantic segmentation method based on scene classification supervision signals is used, then the training complexity is reduced, but the accuracy of pseudo-labels deteriorates

Engineering Contradiction:
Improvetraining complexityVSAvoidaccuracy of pseudo-labels
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary alignment constraint loss function that bridges the gap between scene classification supervision and point-level semantic segmentation. This loss function acts as a mediator to align point cloud features with image features, enabling accurate pseudo-label generation without requiring complex point-level annotations. The alignment constraint loss serves as the intermediary mechanism that transfers supervisory signals from the image modality to the point cloud modality, resolving the contradiction between training simplicity and labeling accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If point cloud category activation maps are used to generate pseudo-labels, then the training process is simplified, but the precision of semantic segmentation results deteriorates

Engineering Contradiction:
Improvetraining process simplicityVSAvoidprecision of semantic segmentation results
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements a feedback mechanism where the alignment constraint loss continuously refines the pseudo-labels during training. The loss function provides feedback signals that adjust the point cloud feature representations to better match the image features, thereby improving the accuracy of generated pseudo-labels. This feedback loop enables the model to iteratively improve segmentation precision while maintaining the simplicity of the training process, as the feedback is automatically computed from the alignment between modalities.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If multi-modal alignment constraints are introduced, then the accuracy of point cloud semantic segmentation is improved, but the computational complexity increases

Engineering Contradiction:
Improveaccuracy of point cloud semantic segmentationVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the alignment constraint computation into distinct modular components: feature alignment loss, semantic alignment loss, and structural alignment loss. Each component addresses a specific aspect of multi-modal alignment independently, allowing for efficient computation and targeted optimization. This segmentation of the alignment process reduces overall computational complexity by breaking down the complex multi-modal alignment task into manageable, specialized sub-tasks that can be computed separately and then combined.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4712045A1Three-dimensional point cloud processing model training method and semantic segmentation model training method, and related device
Publication Date: 2026.03.18 JD DIGITS HAIYI INFORMATION TECHNOLOGY CO LTD
  • EP4712045A1 patent drawingFigure 1
  • EP4712045A1 patent drawingFigure 2~3
  • EP4712045A1 patent drawingFigure 4

AI summary

The present disclosure relates to the technical field of three-dimensional point cloud. Disclosed are a three-dimensional point cloud processing model training method and a semantic segmentation model training method, and a related device. The three-dimensional point cloud processing model training method comprises : processing three-dimensional point cloud data by using a three-dimensional point cloud processing model, so as to acquire information of points in the three-dimensional point cloud data; acquiring information of pixels in two-dimensional image data, wherein the two-dimensional image data and the three-dimensional point cloud data cover the same area; determining an alignment constraint loss of the three-dimensional point cloud data and the two-dimensional image data by using the information of the points and the information of the pixels; determining a classification loss of the three-dimensional point cloud processing model by using classification information, which is predicted by the three-dimensional point cloud processing model, of the points in the three-dimensional point cloud data and pre-marked scene classification information; and training the three-dimensional point cloud processing model by using the alignment constraint loss and the classification loss.