Multispectral Face Detection for Spoof-Resistant Authentication

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Solution Overview

Problem

Facial recognition systems are vulnerable to spoofing, where a nefarious user can gain unauthorized access by presenting a fake face, such as a printed image or three-dimensional model, fooling the system.

Innovation Solution

A multispectral camera captures image data in two electromagnetic spectrum regions, such as infrared and visible, to detect differences characteristic of human skin that are unreproducible by spoofing objects, using a computing device to analyze the image data and determine if it corresponds to a real or spoofed face.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If facial recognition systems use standard image capture, then the system is easy to operate and quick to implement, but the system becomes vulnerable to spoofing attacks

Engineering Contradiction:
Improveanti-spoofing capabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent transitions from standard visible light imaging to multispectral imaging by adding infrared spectral dimension. The camera captures images in both visible and infrared spectrum regions, creating a multidimensional feature space where spoofed faces can be differentiated from real faces based on spectral characteristics that are impossible to replicate with conventional printing or modeling materials.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The system changes the physical parameters of image capture by utilizing different spectral regions (visible and infrared). Real human skin exhibits distinct spectral reflection and absorption characteristics in these regions, while spoofing materials do not. By analyzing feature distances across these spectral parameters, the system achieves reliable spoof detection.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the system captures images in multiple spectral regions, then spoofing detection accuracy improves, but the energy consumption and processing time increase

Engineering Contradiction:
Improveface authentication accuracyVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary action by pre-computing and storing reference feature distances for authentic faces in the database during system initialization. When authentication is required, the system only needs to compute feature distances for the test image and compare against pre-established thresholds, significantly reducing real-time processing energy consumption while maintaining high accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system creates feature distance representations (mathematical copies) of spectral characteristics rather than storing and comparing entire multispectral images. By computing and comparing feature distances in a reduced-dimensional feature space, the system achieves accurate authentication with minimal energy expenditure during the verification phase.

Inventive Principle:
Principle #26Copying

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

The system provides robust facial recognition resistant to spoofing, enhancing security by reducing the risk of identity theft and unauthorized access.

Implementation Method 1

A multispectral camera captures image data in two electromagnetic spectrum regions, such as infrared and visible

Methodology Applied
Scientific EffectInfrared radiation detection: Infrared Radiation

Implementation Method 2

captures image data in two electromagnetic spectrum regions, such as infrared and visible

Methodology Applied
Scientific EffectElectromagnetic spectrum detection: Electromagnetic Induction

Data Source

PatentEP3369036B1Spoofed face detection
Publication Date: 2025.07.02 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3369036B1 patent drawingFigure 1
  • EP3369036B1 patent drawingFigure 2
  • EP3369036B1 patent drawingFigure 3

AI summary

Examples are disclosed herein that relate to detecting spoofed human faces. One example provides a computing device comprising a processor configured to compute a first feature distance between registered image data of a human face in a first spectral region and test image data of the human face in the first spectral region, compute a second feature distance between the registered image data and test image data of the human face in a second spectral region, compute a test feature distance between the test image data in the first spectral region and the test image data in the second spectral region, determine, based on a predetermined relationship, whether the human face to which the test image data in the first and second spectral regions corresponds is a real human face or a spoofed human face, and modify a behavior of the computing device.