Cross-Spectrum Face Recognition via Domain Adaptation

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Solution Overview

Problem

Current face recognition systems face challenges in accurately matching cross-spectrum imagery, particularly under variable poses, due to the large discrepancy between visible and cross-spectrum imagery, leading to decreased performance in profile-to-frontal face matching and increased errors when matching faces across different spectra.

Innovation Solution

A domain adaptation framework is introduced that learns pose-invariant mappings between visible and cross-spectrum image representations, using a modified neural network architecture with a domain and pose invariance transform (DPIT) sub-network and joint loss functions to bridge domain and pose gaps, enabling robust cross-spectrum face recognition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional face recognition systems perform matching in the visible spectrum based on frontal-to-frontal face matching, then matching accuracy is improved, but the system fails to perform effectively in low light environments or when subjects are not facing the camera

Engineering Contradiction:
Improveface matching accuracyVSAvoidenvironmental adaptability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system separates visible spectrum images and thermal spectrum images into different processing streams, with dedicated feature extraction networks for each spectrum type. This segmentation allows each stream to be optimized for its specific spectral characteristics while maintaining overall system accuracy across diverse environments

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A domain adaptation network serves as an intermediary component that receives features from both visible and thermal streams, learns to align the feature distributions across domains, and produces adapted features that enable accurate cross-spectrum matching. This intermediary bridges the gap between different spectral representations

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the system uses thermal spectrum imaging to improve performance in low light conditions, then environmental robustness is improved, but the discrepancy between visible and thermal imagery decreases matching accuracy

Engineering Contradiction:
Improvelow light environment performanceVSAvoidcross-spectrum matching accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system changes the parameter space by transforming thermal spectrum features into a representation that aligns with visible spectrum features through the domain adaptation network. This parameter transformation enables accurate matching despite the fundamental differences in spectral characteristics

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system replaces direct pixel-level comparison between thermal and visible images with a feature-level comparison mechanism. By substituting the mechanical image matching process with neural network-based feature extraction and domain adaptation, the system overcomes the limitations of direct cross-spectrum image comparison

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

3Adaptability or versatility

If the system attempts to match off-pose thermal faces with frontal visible faces, then cross-spectrum recognition capability is improved, but pose variations increase matching errors

Engineering Contradiction:
Improvecross-spectrum recognition capabilityVSAvoidpose variation robustness
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary pose normalization and domain alignment during the training phase, where the domain adaptation network learns to handle pose variations by being trained on diverse pose data. This preliminary preparation enables the system to robustly handle pose variations during inference without requiring explicit pose correction at matching time

Inventive Principle:
Principle #10Preliminary action

4Measurement precision

If conventional FR systems require minimum interocular distance, then identification accuracy is improved, but the system loses advantage in standoff acquisition compared to other modalities

Engineering Contradiction:
Improveidentification accuracyVSAvoidstandoff acquisition capability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system creates a universal face recognition framework that processes both visible and thermal spectrum images through a unified architecture with shared and specialized components. This multi-functional design enables the system to maintain high accuracy while operating effectively at various distances and conditions, combining the advantages of different spectral modalities

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS20230334899A1Learning domain and pose invariance for thermal-to-visible face recognition
Publication Date: 2023.10.19 NUTECH VENTURES LTD
  • US20230334899A1 patent drawing
  • US20230334899A1 patent drawing
  • US20230334899A1 patent drawing

AI summary

A method and system for cross-spectrum face recognition is disclosed. The system for off-pose cross-spectrum to frontal visible face matching, which used modified base architectures to extract image representations along with a new sub-network to simultaneously learn pose and domain invariance using new joint-loss function that combines proposed pose-correction and cross-spectrum losses. The system and method demonstrate significant improvements over state-of-the-art domain adaptation methods not only on pose conditions, but also on baseline and varying expressions. Other aspects, embodiments, and features are also claimed and described.