Gradient-Based Dividing Line Detection for Composed Banknote Counterfeits

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods fail to reliably detect composed counterfeit documents of value, particularly those assembled from genuine and forged parts, as they often produce similar measurement signals to genuine documents, making it difficult to distinguish between real and counterfeit banknotes.

Innovation Solution

The method involves determining signal intensities at multiple measurement points, selecting groups based on typical dividing line positions, calculating gradient values, and evaluating connection strengths by forming products or sums of these values, which are then compared to reference strengths to identify the presence of dividing lines indicative of composed forgeries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional measurement methods (fluorescence properties, reflection measurement) are used to detect counterfeit documents, then genuine counterfeits with similar properties can be identified, but composed counterfeits made from genuine parts produce similar signals and cannot be reliably detected

Engineering Contradiction:
Improvedetection reliabilityVSAvoidmeasurement method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the document into multiple measurement zones (first measurement zone and second measurement zone) and performs separate gradient calculations for each zone. By segmenting the measurement approach and comparing gradient values between zones, the method can detect composited counterfeits that have similar overall fluorescence properties but different local gradient characteristics, thereby improving detection reliability without requiring complex additional hardware.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If gradient values are calculated and compared to detect dividing lines, then composed forgeries can be reliably detected, but the measurement and evaluation process becomes more complex

Engineering Contradiction:
Improvecounterfeit detection precisionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies different evaluation criteria to different measurement zones by calculating gradient values specifically for each zone and comparing them. This local quality approach allows the system to focus on specific areas where composited lines are likely to occur, improving measurement precision while keeping the processing complexity manageable through targeted zone-based analysis rather than whole-document analysis.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent performs preliminary gradient calculations for multiple measurement zones before making the final authenticity determination. By pre-calculating and storing gradient values for each zone, the system prepares the data in advance, which simplifies the final comparison and decision-making process, thereby reducing the overall evaluation complexity while maintaining high detection precision.

Inventive Principle:
Principle #10Preliminary 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

This approach allows for the reliable identification of counterfeit documents by determining a connection strength that differs significantly from reference values, providing a high probability of detecting dividing lines that indicate composed forgeries, thereby enhancing the authenticity check of documents.

Implementation Method 1

an optical measurement signal, in particular a fluorescence signal, is used as the measurement signal

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP2143081B1Method and device for testing value documents
Publication Date: 2018.10.24 GIESECKE & DEVRIENT CURRENCY TECHNOLOGY GMBH
  • EP2143081B1 patent drawingFigure 1a~1c
  • EP2143081B1 patent drawingFigure 2a~3
  • EP2143081B1 patent drawingFigure 2c

AI summary

The invention relates to a method and a device for detecting counterfeit value documents, such as composed counterfeits made up of parts of different value documents. In the method according to the invention, the signal intensity of a measurement signal is determined at a plurality of measurement points on a value document. For one or more selected groups of measurement points, located particularly along certain directions on the value document, gradient values are determined for the signal intensities. The gradient values of a group are then linked to a connection strength of the group, providing quantitative information about to what extent a large gradient value exists continuously within the corresponding group. The presence of a dividing line in the region of the selected group of measurement points can be deduced from a relatively great connection strength.