Projection Apparatus Selective Watermark Embedding
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Solution Overview
Problem
Existing projection systems face challenges in combining digital watermarks and calibration patterns with projection images without compromising display quality, leading to issues with copyright protection and image correction, as described in Japanese Patent Application Publication No. 2015-192389, where the digital watermark may not be detectable in all cases, affecting the protection of projection images and the correction of image shape and quality.
Innovation Solution
A projection apparatus that acquires characteristic values of partial regions of an input image, determines target regions for displaying graphics based on these values and predetermined conditions, and controls the display of graphics only in those regions, ensuring low visibility and enabling precise detection of combining information such as calibration patterns and digital watermarks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a digital watermark is superimposed on all pixels of a projection image, then copyright protection is strengthened, but display quality deteriorates due to visible artifacts in high-visibility regions
Solution Approach 1:
The patent applies local quality by differentiating treatment across different regions of the projection image. It calculates visibility indices for each pixel and selectively embeds watermarks only in regions where the visibility index indicates low visual impact. This ensures that watermarks are placed in areas where they will not be easily perceived by users, thereby maintaining display quality while still providing copyright protection through selective watermarking.
2Object-affected harmful factors
If a graphic is not superimposed on pixels with high visual change characteristics, then display quality is maintained, but copyright protection becomes unreliable as watermarks may not be detectable
Solution Approach 1:
The patent employs feedback by calculating a visibility index for each pixel based on its visual characteristics and using this index to determine watermark embedding decisions. The system continuously assesses the visual impact of potential watermark placements and adjusts embedding strategies accordingly. This feedback mechanism ensures that watermarks are embedded in regions where they will be detectable by cameras while minimizing visual artifacts, thus maintaining both display quality and copyright protection reliability.
3Reliability
If graphics are embedded in regions with low visibility characteristics, then copyright protection and image correction become reliable, but the overall effectiveness is reduced when no suitable regions exist in certain images
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the visibility threshold and watermark embedding strength based on the specific characteristics of each projection image. The system calculates visibility indices for all pixels and adapts its watermarking strategy according to the distribution of these indices. When suitable low-visibility regions are available, watermarks are embedded with higher confidence; when fewer suitable regions exist, the system adjusts embedding parameters to maintain effectiveness. This adaptive parameter adjustment ensures reliable graphic detection across diverse image types while maximizing applicability.
Data Source
AI summary
An apparatus includes an acquisition unit configured to acquire a characteristic value of each of partial regions of an input image; a determination unit configured to determine target regions for which a graphic is displayed, out of the partial regions, based on the acquired characteristic values and a predetermined condition; and a control unit configured to control so that the graphic is displayed in the target regions of the input image.