Meta-Learning Sample Weighting for Face Recognition Bias

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Solution Overview

Problem

Deep face recognition models face challenges due to biased training data distributions, leading to lower accuracy in certain conditions like occlusions and unfairness towards minority ethnicities, as it is impractical to collect data covering a wide variety of variations.

Innovation Solution

A computer-implemented method using meta-learning to train deep face recognition models by calculating sample weights and updating the model based on gradients from both training and validation batches, incorporating instance-level variation-aware loss and meta-learning to rebalance data distributions across multiple factors of variation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If uniform sampling of training data is used, then training process is simple, but accuracy along certain factors (occlusions) decreases and model fairness deteriorates

Engineering Contradiction:
Improvetraining process simplicityVSAvoidmodel accuracy and fairness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by assigning different weights to different training samples based on their characteristics. Specifically, it calculates sample weights using a meta-learner that considers instance-level variations, giving higher weights to underrepresented or difficult samples (e.g., occluded faces, minority ethnicities) while maintaining uniform sampling for the overall training process. This resolves the contradiction by making the training process simple overall while achieving high accuracy and fairness through local sample-weighting.

Inventive Principle:
Principle #3Local quality

2Reliability

If training data covers a wide variety of variations, then model accuracy and fairness improve, but data collection becomes impractical

Engineering Contradiction:
Improvemodel accuracy and fairnessVSAvoiddata collection feasibility
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-calculating sample weights using a meta-learner trained on available data characteristics. Instead of collecting more diverse data, the method proactively identifies underrepresented variations in the existing training set and assigns higher weights to those samples. This preliminary weighting adjustment compensates for data distribution biases without requiring impractical data collection efforts, thereby improving accuracy and fairness while maintaining data collection feasibility.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If sample weights are dynamically updated using meta-learning, then dataset bias is mitigated, but computational complexity increases

Engineering Contradiction:
Improvebias mitigation effectivenessVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies partial action by implementing meta-learning only for calculating sample weights rather than for the entire training process. The meta-learner is trained once to learn the mapping from sample characteristics to weights, and then these weights are applied during standard training. This partial application of meta-learning achieves effective bias mitigation while avoiding the excessive computational complexity of full meta-learning training, resolving the contradiction between effectiveness and complexity.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11977602B2Domain generalized margin via meta-learning for deep face recognition
Publication Date: 2024.05.07 NEC CORP
  • US11977602B2 patent drawing
  • US11977602B2 patent drawing
  • US11977602B2 patent drawing

AI summary

A method for training a model for face recognition is provided. The method forward trains a training batch of samples to form a face recognition model w(t), and calculates sample weights for the batch. The method obtains a training batch gradient with respect to model weights thereof and updates, using the gradient, the model w(t) to a face recognition model what(t). The method forwards a validation batch of samples to the face recognition model what(t). The method obtains a validation batch gradient, and updates, using the validation batch gradient and what(t), a sample-level importance weight of samples in the training batch to obtain an updated sample-level importance weight. The method obtains a training batch upgraded gradient based on the updated sample-level importance weight of the training batch samples, and updates, using the upgraded gradient, the model w(t) to a trained model w(t+1) corresponding to a next iteration.