Minutiae Graph Comparison for Interoperable Fingerprint Matching

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Solution Overview

Problem

Existing fingerprint identification methods require fingerprint images, which may not be available in older databases, and are often not interoperable due to varying image formats and qualities, and methods using minutiae-encoded graphs struggle with identifying a single dactylogram among a set.

Innovation Solution

A method that projects minutiae coordinates into a higher-dimensional space using a trained projection model, applies graph neural networks for inference and encoding, and aggregates the results into a scalar score, enabling comparison of minutiae lists without requiring image data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fingerprint images are used for identification, then accurate comparison can be performed, but the method cannot be applied to older databases that only store minutiae coordinates

Engineering Contradiction:
Improvecompatibility with different database typesVSAvoididentification accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent transforms the identification approach by changing the input parameters from image-based features to minutiae coordinate-based features. The system accepts minutiae lists with coordinates and orientations as input, processes them through neural network models trained specifically on coordinate data, and produces identification results comparable to image-based methods. This parameter transformation enables compatibility with databases storing only minutiae coordinates while maintaining identification accuracy.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If different image formats and qualities are used in databases, then more fingerprints can be stored, but interoperability between systems decreases

Engineering Contradiction:
Improvedatabase interoperabilityVSAvoidnumber of storable fingerprints
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent extracts the essential identification features from fingerprint images during the enrollment phase, storing only the critical minutiae coordinates, orientations, and ridge flow directions in the database. This extraction approach eliminates the need to store complete images in various formats, enabling seamless interoperability between different systems while maintaining the ability to store and process a large quantity of fingerprints using a standardized, compact data structure.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If traditional screening algorithms are used to eliminate candidates, then processing speed improves, but precision in identifying the correct fingerprint decreases

Engineering Contradiction:
Improveidentification speedVSAvoidmatch accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements preliminary action by pre-training neural network models on comprehensive datasets during an offline phase. The models learn optimal feature representations and comparison metrics in advance. During online identification, these pre-trained models rapidly process minutiae lists and compute similarity scores without requiring iterative screening, thereby achieving both high processing speed and high precision through the preliminary learning phase.

Inventive Principle:
Principle #10Preliminary action

4Measurement precision

If more computational resources are allocated for processing, then identification accuracy improves, but processing time increases

Engineering Contradiction:
Improveidentification accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces traditional mechanical comparison algorithms with neural network-based computational models. The neural networks, trained offline to learn optimal feature representations and decision boundaries, perform rapid similarity computations during online identification. This substitution leverages the parallel processing capabilities of neural networks and optimized tensor computations, achieving high identification accuracy with reduced processing time compared to traditional iterative comparison methods.

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

Data Source

PatentEP4607478A1Method for comparing two typegrams
Publication Date: 2025.08.27 IDEMIA PUBLIC SECURITY FRANCE
  • EP4607478A1 patent drawingFigure 1
  • EP4607478A1 patent drawingFigure 2
  • EP4607478A1 patent drawingFigure 3~4

AI summary

Method for comparing two dactylograms from the lists of their minutiae, said method takes, as input data, a first source matrix MS1 of the coordinates of each minutiae of a first list L1 of minutiae of a first dactylogram and a second source matrix MS2 of the coordinates of each minutiae of a second list L2 of minutiae of a second dactylogram, and provides, as output data, a correspondence score between the two lists L1, L2 of minutiae.