Dynamic Facial Verification Lighting Against Replay Spoofing

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Solution Overview

Problem

Image-based verification processes, particularly facial recognition, are susceptible to replay attacks and spoofing due to the increased accessibility of high-resolution image and video capture, which complicates the differentiation between live subjects and recorded images.

Innovation Solution

Implementing a controllable light source to set ambient lighting conditions proactively, using lighting direction, intensity, and color to encode data, and adjust captured images to ensure live presence, thereby minimizing the risk of replay attacks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple images are captured and processed to verify document authenticity, then verification reliability is improved, but processing time increases

Engineering Contradiction:
Improveverification reliabilityVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary actions by capturing multiple images simultaneously or in rapid sequence before verification begins. The illumination device illuminates the document from multiple angles pre-configured, and the image sensor captures reflected light patterns that encode document features in advance, allowing faster verification processing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The illumination device dynamically changes illumination angles and patterns during the imaging process. By dynamically adjusting the direction and intensity of light sources, the system captures multiple views of the document in a single coordinated operation, improving verification reliability without proportionally increasing processing time.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If dynamic lighting is used to illuminate documents from multiple angles, then image quality and verification accuracy are improved, but device complexity increases

Engineering Contradiction:
Improveimage qualityVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The illumination device is segmented into multiple independent light sources positioned at different angles. Each light source can be controlled independently to illuminate specific portions of the document from its unique angle, allowing the system to achieve high image quality through coordinated multi-angle illumination without requiring a single complex illumination system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The illumination device is designed with multi-functionality, where a single device structure performs multiple functions by illuminating the document from various angles. The same illumination device can capture front surface features, edge features, and security element characteristics by adjusting which light sources are activated, reducing the need for multiple separate imaging systems.

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

3Productivity

If multiple images are processed simultaneously, then verification speed is improved, but computational requirements and energy consumption increase

Engineering Contradiction:
Improveverification speedVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The system merges the processing of multiple images by integrating feature extraction from all captured images into a single unified verification process. Instead of processing each image separately, the system combines information from multiple angles and illumination conditions to generate a comprehensive document signature, improving verification speed while distributing computational load efficiently.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The verification process maintains continuity by processing image data in a continuous pipeline as images are captured. The system continuously extracts features, compares them against stored references, and generates verification results without interrupting the imaging process, maximizing productivity while optimizing energy usage through sustained operational states rather than repeated start-stop cycles.

Inventive Principle:
Principle #20Continuity of useful action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances the security of image-based verification by ensuring that captured images are taken under controlled lighting conditions, making it difficult to spoof the system and verifying the authenticity of the subject's presence.

Implementation Method 1

the image sensor to capture reflected light from the document

Methodology Applied
Scientific EffectReflected light: Reflection

Data Source

PatentEP3759646B1Dynamic lighting for image-based verification processing
Publication Date: 2026.04.29 VISA INTERNATIONAL SERVICE ASSOCIATION
  • EP3759646B1 patent drawingFigure 1
  • EP3759646B1 patent drawingFigure 2
  • EP3759646B1 patent drawingFigure 3

AI summary

A facial recognition system may monitor a light source that causes a unique pattern of light to be projected on the subject during image capture. The lighting pattern may include intensity, color, source location, pattern, modulation, or combinations of these. The lighting pattern may also encode a signal used to further identify a location, time, or identity associated with the facial recognition process. In some embodiments the light source may be infrared or another frequency outside the visible spectrum but within the detection range of a sensor capturing the image.