Covert Marking via Laser Intensity Modulation
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Solution Overview
Problem
Monochrome printing devices are unable to transfer colored covert markings, and attempting to hide dot patterns using a black channel makes them visible, limiting the ability to create undetectable covert patterns on print media.
Innovation Solution
A system that adjusts laser intensity levels in monochrome printers to create covert dot patterns by designating pixels to alter their grayscale, using a laser intensity level conversion table to change pixel intensities, allowing for covert markings that are not easily detectable by the human eye.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If monochrome printing devices use black channel to hide dot patterns, then covert markings can be created, but the dot patterns become visible
Solution Approach 1:
The patent changes the parameter of laser intensity levels by designating specific pixels to have different laser intensity levels than their original values. This creates covert dot patterns through grayscale variations that are imperceptible to the human eye while still encoding information on the print medium.
Solution Approach 2:
The patent utilizes grayscale variations (effectively monochrome color changes) by adjusting laser intensity levels to create covert markings. The designated pixels are rendered at different grayscale levels that blend with the overall image, making the covert patterns invisible to human observation.
2Object-affected harmful factors
If colored covert markings are used, then detectability is reduced, but monochrome printing devices cannot transfer colored markings
Solution Approach 1:
The patent compensates for the lack of color capability by changing the laser intensity level parameter of selected pixels. This creates covert markings through subtle grayscale variations that mimic the effect of colored covert markings, allowing monochrome devices to achieve similar stealth capabilities.
Solution Approach 2:
The patent effectively copies the functionality of colored covert marking systems by using grayscale intensity variations. The laser intensity level adjustments replicate the concealment effect of colored markings adapted to the constraints of monochrome printing devices.
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
Enables the creation of covert dot patterns on both image and non-image portions of print media, enhancing the security and stealth of markings produced by monochrome printing devices without affecting the printing process's performance.
Implementation Method 1
covert dot patterns are formed on both image and non-image portions of print medium using laser intensity modulation to adjust the grayscale of the covert dot patterns
Data Source
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AI summary
Examples described herein relate to a system consistent with the disclosure. For instance, the system may comprise a printing device including hardware to form an image on a print medium, a memory resource, and a controller to receive a print job to form the markings on the print medium, designate a pixel of the received print job to form a covert dot pattern on the markings, where the pixel corresponds to a first laser intensity level; and adjust a laser intensity of the printing device to a second laser intensity level based on the first laser intensity level of the designated pixel to form the covert dot pattern.