Anti-counterfeiting Pattern for Identification Documents
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing identification documents with graphical anti-counterfeiting features, such as guilloche patterns, are vulnerable to reproduction and modification due to predictable patterns and inadequate consideration of the Human Visual System, making them susceptible to counterfeiting and fraudulent alterations.
Innovation Solution
A method that inserts a security pattern into identification documents by modifying pixel characteristics based on surrounding pixel texture and luminosity levels using a secret function, allowing for visual inspection and reader-based verification while minimizing image degradation and ensuring authenticity detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a predictable guilloche pattern is used for security features, then visual inspection verification is enabled, but the document becomes vulnerable to scanning and reproduction by infringers
Solution Approach 1:
The patent applies local quality by varying the grey level of individual guilloche pixels based on their local neighborhood characteristics. Each pixel's grey level is determined by a secret function that considers the characteristic levels and texture levels of surrounding pixels, creating locally adaptive security features that maintain visual inspectability while preventing global pattern reproduction
Solution Approach 2:
The patent changes the parameter of pixel grey level dynamically based on local image characteristics. Instead of using a fixed or predictable grey level pattern, the grey level of each pixel is modified according to a secret function that takes into account the characteristic level and texture level of its neighborhood, making the pattern unpredictable while maintaining visual coherence
2Illumination intensity
If the grey level of guilloche pixels is reversed to improve visibility, then the pattern becomes perceptible to naked eye, but the contrast may be too high and affect image perception
Solution Approach 1:
The patent applies local quality by adapting the grey level modification of each guilloche pixel to its local neighborhood characteristics. Pixels in different regions are modified by different amounts based on the characteristic level and texture level of their surroundings, ensuring optimal visibility while minimizing impact on the overall image perception
Solution Approach 2:
The patent applies partial action by selectively modifying only the necessary pixel grey levels to achieve adequate visibility. Instead of uniformly reversing all pixel luminosity, the secret function determines the appropriate modification level for each pixel, applying just enough contrast enhancement to make the pattern perceptible without excessive contrast that would degrade image quality
3Reliability
If personalized patterns are generated for each document to prevent counterfeiting, then security is improved, but visual inspection by policemen becomes impossible and dedicated reader devices are required
Solution Approach 1:
The patent applies universality by using the same predictable guilloche pattern structure for all documents while incorporating secret function-based grey level modifications. This allows the pattern to serve dual purposes: maintaining visual inspectability like traditional patterns while providing enhanced security through the secret grey level encoding that requires dedicated readers for full verification
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a method for securing a first image by means of graphical anti-counterfeiting means and to a method for securing an identification document with such graphical anti-counterfeiting means. The invention also relates to a secure identification document that allows detecting either a fraudulent modification of the existing personalization or a fraudulent falsified document. For that, graphical anti-counterfeiting image is inserted into an identification image, each image being defined by a plurality of pixels. The characteristic level (for example grey level) of each pixel i of the graphical anti-counterfeiting image is linked, by a function F, to a matrix Oi of pixels defined in the identification image, said pixels of the matrix Oi surrounding the location i of a pixel of the graphical anti-counterfeiting image, said function F taking into account the characteristic level (for example average grey level) G(Oi) and the texture level T(Oi) of said matrix Oi.