Composite Masking for HD Video Watermark Invisibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-definition video watermarking systems face challenges in maintaining invisibility and robustness against scaling and video processing attacks, with traditional masks failing to distinguish between contour and texture regions, leading to block artifacts and decreased imperceptibility.
Innovation Solution
A composite masking system that generates a composite mask by multiplying Noise Visibility Function (NVF), adaptive dithering, and contour masks, which are applied to the luminance channel of an original image to embed an extended watermark pattern, improving invisibility and robustness against scaling attacks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a watermark pattern is repeatedly extended to improve robustness against scaling attacks, then robustness is improved, but block artifacts occur and invisibility deteriorates
Solution Approach 1:
The patent applies different processing to different regions of the image by using masks that adapt to local characteristics. The watermark embedding strength varies across different regions based on local image properties such as texture and edge density, allowing robust embedding in some regions while maintaining invisibility in others.
Solution Approach 2:
The patent changes the embedding parameters dynamically based on local image characteristics. By adjusting the mask values according to local texture and edge properties, the system optimizes the balance between robustness and invisibility for each region, preventing block artifacts while maintaining scaling robustness.
2Strength
If traditional NVF mask is used for watermark embedding, then embedding strength is improved in contour and texture regions, but contour regions are corrupted and severe distortions occur
Solution Approach 1:
The patent distinguishes between different types of regions (contour vs. texture) and applies different embedding strategies to each. The mask is designed to reduce embedding strength in contour regions while maintaining it in texture regions, preventing distortions in sensitive areas.
Solution Approach 2:
The patent introduces an additional masking layer that acts as an intermediary between the NVF mask and the watermark embedding process. This intermediate mask specifically protects contour regions by further reducing embedding strength in those areas, preventing the corruptions and distortions that occur with traditional NVF masking alone.
3Reliability
If dithering masking is applied uniformly to all watermark patterns, then embedding robustness is improved, but watermark embedding strength cannot be controlled and imperceptibility performance decreases
Solution Approach 1:
The patent makes the dithering mask dynamic by adapting its strength and application based on local image characteristics. Rather than uniform dithering, the mask values are adjusted according to local texture and edge properties, enabling both robustness and controllable embedding strength.
Data Source
AI summary
A composite masking system and method for improving the invisibility of high-definition video watermarking. The composite masking system includes a watermark generation module, a mask generation module, and watermark embedment means. The watermark generation module generates a basic watermark pattern using a private key, and generate a watermark pattern by repeatedly extending the basic watermark pattern. The mask generation module generates a Noise Visibility Function (NVF) mask using NVF masking means, an adaptive dithering mask using adaptive dithering masking means, and a contour mask using contour masking means. The watermark embedment means generates a composite mask by multiplying the NVF mask, the adaptive dithering mask and the contour mask together, multiplying the composite mask and the extended watermark pattern together, and embedding the result of the second multiplication in the luminance channel of an original image.