Fingerprint Detection Using Luminous Intensity Zone Segmentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for detecting fingerprints in images require the projection of test cards and analysis for characteristic shapes, making them complex and resource-intensive.

Innovation Solution

A method that acquires an illuminated hand image using an optical sensor without contact, determines zones of high luminous intensity, and applies filtering criteria to select potential fingerprint zones based on shape, texture, and color, reducing the need for extensive calculations and mechanical contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If test cards are projected and characteristic shape analysis is performed, then fingerprint detection accuracy is improved, but device complexity and calculation resources increase

Engineering Contradiction:

Improvefingerprint detection accuracyVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential luminous intensity information from the hand image, ignoring complex test card projections and characteristic shape analyses. By focusing solely on luminous intensity thresholds and continuous zones, the method achieves fingerprint detection without requiring complex projection systems or detailed shape analysis, thus reducing device complexity while maintaining detection capability

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the hand image into continuous zones based on luminous intensity thresholds. This segmentation approach divides the image processing task into manageable regions of interest, allowing the system to focus computational resources only on zones that meet the luminous intensity criteria, thereby reducing overall calculation complexity while preserving detection accuracy

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If test cards are projected and characteristic shape analysis is performed, then fingerprint detection accuracy is improved, but calculation time increases

Engineering Contradiction:

Improvefingerprint detection accuracyVSAvoidcalculation time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only luminous intensity data from the image, eliminating the need for time-consuming test card projections and characteristic shape analyses. By focusing exclusively on luminous intensity thresholds and continuous zone identification, the method significantly reduces calculation time while maintaining the ability to detect fingerprints through the identification of high-intensity continuous zones

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs only the necessary portion of image analysis by focusing solely on luminous intensity thresholds and continuous zone identification, rather than performing complete characteristic shape analyses. This partial action approach achieves sufficient detection accuracy for fingerprint identification while dramatically reducing calculation time and computational resource requirements

Inventive Principle:

Principle #16Partial or excessive action

3Measurement precision

If contact-based image acquisition is used, then image quality is improved, but ease of operation deteriorates

Engineering Contradiction:

Improveimage qualityVSAvoidease of operation

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces mechanical contact-based image acquisition with optical imaging. By using an optical sensor to capture images of the illuminated hand without physical contact, the system eliminates the need for mechanical pressing or contact with the hand, thereby improving ease of operation while maintaining sufficient image quality for detecting luminous intensity patterns and continuous zones

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This method simplifies fingerprint detection by targeting high-intensity zones, reducing calculation time and resources, and allowing for non-contact, on-the-fly image acquisition, making it practical for use in mobile devices.

Implementation Method 1

a) a step of acquiring the image of at least one illuminated portion of hand with the aid of an optical sensor

Methodology Applied

Scientific EffectLuminous intensity detection: Photoelectric Effect

Data Source

PatentUS10248832B2Method of determining, in an image, at least one zone liable to represent at least one finger of an individual

Publication Date: 2019.04.02 IDEMIA PUBLIC SECURITY FRANCE

AI summary

A method of detecting zones liable to contain at least one finger print in an image of at least one portion of hand of an individual includes a step of acquiring the image, a step of determining a plurality of zones of the acquired image and a first selection step. The step of determining a plurality of zones determines that each zone is a continuous zone of points of the acquired image which each exhibit a luminous intensity level greater than or equal to a selected luminous intensity threshold value. The first selection step selects, from among the zones determined, the zones which are liable to represent at least one print of a finger.