Variable-Shape Image Patterns for Copy-Resistant Authentication
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Solution Overview
Problem
Conventional methods for embedding additional information in printed documents for authenticity verification fail to prevent extraction of this information when the document is copied using a copying machine.
Innovation Solution
An image processing apparatus that embeds a pattern with specific frequency characteristics in print data, using a multiplexing unit to superimpose document ID information on the print medium, where a first shape contacts a second shape, with one part larger than the other, to minimize visibility and facilitate extraction from printed copies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional information is embedded in printed documents for authenticity verification, then authenticity verification capability is improved, but the embedded information can be extracted when the document is copied
Solution Approach 1:
The patent changes the physical parameters of the embedded information by using variable dot sizes within the same pattern. Different dots have different sizes (some larger, some smaller) which creates a visual illusion that obscures the embedded information while maintaining its structural integrity for authentication purposes. This parameter variation makes it difficult for copying machines to accurately reproduce the subtle size differences, thereby preventing extraction of the embedded information.
2Reliability
If additional information is embedded in printed documents, then authenticity verification is enabled, but visibility of the embedded information increases making it easier to detect
Solution Approach 1:
The patent applies local quality by creating patterns where specific dots have different sizes depending on their position and function within the pattern. Some dots are intentionally made larger while others are smaller, creating local variations in visual properties. This local differentiation creates a complex visual structure that is difficult to detect as embedded information, while still encoding authentication data through the systematic variation of dot sizes.
Data Source
AI summary
An image processing apparatus that embeds a pattern including a specific frequency characteristic in print data to add additional information to the print data, the image processing apparatus includes a print data obtaining unit configured to obtain data to be printed on a print medium, and a multiplexing unit configured to perform multiplexing processing on the additional information to be embedded in the print data, wherein the additional information to be subjected to the multiplexing processing by the multiplexing unit is formed of a first shape and a second shape within a region on the print medium, and wherein the first shape is created based on the additional information, the second shape contacts with the first shape, and a part of the first shape is larger than another part of the first shape.