3D Segmentation Training Using Bayesian Pseudo-Label Filtering

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Solution Overview

Problem

Existing machine-learning based 3D segmentation models require extensive labeled datasets, which are difficult to obtain, and semi-supervised training methods suffer from confirmation bias and unreliable uncertainty estimators, limiting their performance.

Innovation Solution

A semi-supervised training method using Bayesian statistics to estimate uncertainty of pseudo-labels generated by a pre-trained model, filtering out unreliable labels through entropy-based thresholding and unanimous voting, allowing training on both labeled and unlabeled datasets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If self-training methods use pseudo-labels from a pre-trained model to train on unlabeled datasets, then the model can be trained with more data, but confirmation bias limits performance

Engineering Contradiction:
Improveamount of training dataVSAvoidperformance reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent introduces an uncertainty estimator as an intermediary component that evaluates the reliability of pseudo-labels before they are used for training. This mediator filters out low-confidence predictions, preventing confirmation bias from degrading model performance while still allowing the incorporation of abundant unlabeled data.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements a feedback mechanism where the uncertainty estimator continuously evaluates pseudo-label quality and provides feedback to the training process. High-uncertainty pseudo-labels are excluded from training, creating a feedback loop that maintains performance reliability while leveraging large datasets.

Inventive Principle:
Principle #23Feedback

2Reliability

If thresholding schemes filter pseudo-labels based on confidence level, then confirmation bias is reduced, but uncertainty estimators using softmax function lack reliability

Engineering Contradiction:
Improvepseudo-label reliabilityVSAvoiduncertainty estimation precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the parameter used for uncertainty estimation from softmax confidence scores to entropy-based measurements. This parameter transformation provides a more reliable and calibrated uncertainty estimate, enabling effective thresholding that accurately identifies high-quality pseudo-labels without the limitations of softmax-based approaches.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system replaces the conventional softmax-based uncertainty estimation mechanism with an entropy-based estimation approach. This substitution provides more accurate and reliable uncertainty measurements, improving the effectiveness of pseudo-label filtering while maintaining computational efficiency.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If extensive labeled datasets are used for training segmentation models, then model performance is improved, but labeled datasets cannot be easily obtained

Engineering Contradiction:
Improvemodel performanceVSAvoiddata acquisition ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent implements a self-service approach where the model generates its own training data through pseudo-labeling of unlabeled datasets. The uncertainty estimator enables the system to self-evaluate and select high-quality pseudo-labels, creating a self-sufficient training pipeline that reduces dependence on manually labeled data while maintaining performance.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs preliminary action by pre-training the model on available labeled data to establish initial competence. This preliminary training enables the model to generate reliable pseudo-labels for unlabeled data, creating a bootstrapping effect that expands training data availability without requiring extensive manual labeling from the outset.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4607474A1Methods for segmentation tasks
Publication Date: 2025.08.27 TOYOTA JIDOSHA KK
  • EP4607474A1 patent drawingFigure 1
  • EP4607474A1 patent drawingFigure 2~3
  • EP4607474A1 patent drawingFigure 4~6

AI summary

A computer-implemented method for training a segmentation model is provided. The method comprises: (S10) pre-training a segmentation model under supervised learning using a labeled dataset; (S20) generating ensembles of pseudo-labels associated to elements of an unlabeled dataset using stochastic forward passes with the pre-trained segmentation model; (S30) estimating the uncertainty of the pseudo-labels for each element of the unlabeled dataset using Bayesian statistics over the ensembles of pseudo-labels; (S40) identifying reliable elements in the unlabeled dataset, the reliable elements being characterized by having pseudo-labels with an estimated uncertainty that is inferior to a predetermined threshold; and (S50) training the segmentation model using a new training dataset comprising the labeled dataset and the reliable elements with associated pseudo-labels.