Micro-gradation QR code embedding for document security and history tracking
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Solution Overview
Problem
Current methods for securing and tracking printed documents are inadequate, as they fail to prevent unauthorized copying and do not effectively record the document's handling history, with limitations in data capacity and visibility of embedded information.
Innovation Solution
An image processing apparatus that generates and embeds a two-dimensional code with encrypted data and processing history within a document, using a gradation pattern to securely add and read additional data without affecting image quality, allowing for secure processing and history tracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a QR code is added to a document, then additional data can be embedded without requiring a separate area and substantially without making human eyes recognize degradation of image quality, but the data capacity is limited and the code occupies space that could be used for document content
Solution Approach 1:
The patent transitions from traditional QR codes that use binary black-and-white patterns to a micro-gradation approach that utilizes grayscale variations. By embedding data in the gradation (shadow) portions of the document image at a resolution higher than human eyes can perceive, the system increases data capacity without occupying additional visual space. The code is distributed across the entire document surface rather than concentrated in a separate QR code area.
Solution Approach 2:
The patent applies different quality levels to different portions of the document. The micro-gradation data is embedded in the shadow portions with a resolution higher than what is visible to human eyes, while the main document content maintains its original quality. This allows data embedding without degrading the visible document appearance, effectively using the 'hidden' micro-gradation layers for data storage.
2Reliability
If visible watermark information is used to restrain copying, then copying can be restrained by making the background unreadable to scanners, but the copying itself cannot be prevented and the handling history cannot be checked
Solution Approach 1:
The patent segments the document into multiple functional layers: (1) the visible document content, (2) the micro-gradation data layer containing encrypted security information and handling history, and (3) the human-eye-visible portion. By separating security data from visible content, the system allows scanners to read the document while the micro-gradation layer prevents unauthorized copying and tracks handling history through encrypted data that requires special processing to access.
Solution Approach 2:
The patent introduces an intermediary processing layer that decrypts and processes the micro-gradation data. This intermediary layer (the micro-gradation decoding system) acts as a mediator between the embedded encrypted data and the user's access to information. The system requires specific processing to access the handling history and security information, preventing direct access while allowing authorized users to view the data through the intermediary decoding process.
3Quantity of substance
If additional data is embedded in document design, then data can be added without separate area, but it becomes difficult to estimate the design corresponding to page background and read patterns embedded in high frequency components
Solution Approach 1:
The patent changes the resolution parameter of the embedded data from standard QR code resolution to a much higher micro-gradation resolution. By using a resolution of 72 dpi or higher for the micro-gradation data while maintaining lower visible resolution for the document content, the system achieves high data capacity while keeping the embedded patterns imperceptible to human eyes and scanners. The parameter change in resolution creates a separation between the data layer and the visible layer.
Data Source
AI summary
In a digital multi-function peripheral, a QR code generation section generates image data of a QR code on the basis of first data for security of obtained image data. An encryption section encrypts second data for security of the image data. A micro gradation generation section generates a micro gradation (a gradation pattern) on the basis of the second data having been encrypted by the encryption section and history data, and adds the micro gradation to the image data of the QR code generated by the micro gradation QR code generation section.