With the widespread adoption of digital office systems, electronic documents have become the primary medium for information storage and dissemination. However, PowerPoint (PPT) documents are vulnerable to unauthorized photography during presentations, leading to potential sensitive information leakage and copyright infringement. Traditional document security measures, such as password protection and access control, fail to prevent offline photography attacks, while existing digital watermarking techniques face challenges due to PPT's dynamic characteristics and cross-channel distortion. To address these issues, this paper proposes a camera shooting resilient watermarking for PowerPoint presentation. The scheme first selects the master layout backdrop as the watermark carrier according to PPT's compositional features, enabling globally consistent watermark deployment without interfering with document editing functions. By systematically analyzing distortion characteristics during camera-shooting, we identify an optimal frequency band for watermark embedding. Furthermore, a cost-constrained adaptive embedding strategy is adopted to enhance watermark robustness while maintaining imperceptibility. Experimental results demonstrate that the proposed solution effectively resists interference in various complex photography scenarios, providing a viable approach for protecting PPT documents.

The proliferation of video applications has exacerbated digital piracy issues, notably evidenced by unauthorized video digital editing and camcording processes. While existing research has introduced robust watermarking methods to safeguard video copyrights, these methods often address specific attack scenarios, limiting their overall efficacy. To address this problem, we propose a robust blind video watermarking scheme based on Frequency-Spherical Cavity Transformation (FSCT), offering a comprehensive solution for both digital editing and camcording processes. Our approach treats the spatial and temporal aspects of the video as a 3D cube, utilizing FSCT to ensure temporal translational invariance and resilience against spatial attacks. To mitigate artifacts induced by motion characteristics, we analyze the properties of FSCT and introduce a visual quality optimization strategy, enhancing imperceptibility while ensuring robustness. Simultaneously, during extraction process, the watermark can be successfully retrieved from video camcording with only a specified time interval, eliminating the need for temporal synchronization. Through extensive experimentation, the proposed method exhibits superior robustness against digital editing and camcording compared to existing methods.

In watermarking schemes, deriving the geometric invariants of the multimedia content is crucial for modern watermarking against geometric deformations. The invariants based on orthogonal moments can effectively describe the semantic content of multimedia due to their excellent mathematical properties. Modulating watermarked signals into these invariants can yield satisfactory geometric robustness. However, with the emerging risks posed by generative large models, the current theoretical analysis of the relationship between invariants and watermarking is still limited, and the intrinsic connection between them is neglected to varying degrees when designing moments-based watermarking schemes. To bridge this gap, we propose a set of design principles, including the texture complexity priority principle, uniform zeros distribution priority principle, and invariants conjugation priority principle, and reveal the critical influence of the mathematical properties of moments on video watermarking. Based on the above principles, we also propose a texture-aware adaptive video watermarking scheme based on orthogonal moments. Extensive experiments show that the proposed video watermarking scheme outperforms state-of-the-art watermarking algorithms regarding imperceptibility, robustness, and computational complexity.

The prevalence of digital content leakage via screen capture highlights the urgent need for robust watermarking solutions capable of withstanding cross-media transmission. Current approaches primarily focus on developing watermarking techniques resilient to screen-shooting distortions, where distinguishing the watermark signal from these distortions is paramount. In contrast, our study addresses an inverse problem by investigating the generation patterns of noise during screen-shooting and considering them as feasible representations of watermark signals. Leveraging Moiré patterns as one of the distortion signals naturally generated by the interaction between electronic screens and camera sensors, we propose Moiré-watermark, presenting watermark information encoded into meticulously crafted Moiré patterns within images. To enhance the naturalness of Moiré-watermark amidst the irregularities of screen-shooting Moiré patterns, we encode watermark signals using gratings at different angles. A corresponding angle-based decoding method facilitates effective blind extraction of watermarks. Comprehensive experimental evaluations under diverse conditions of distance, angle, lighting, and across various capturing and display devices, alongside comparisons with existing methods, validate the superior performance of Moiré-watermark.

The widespread adoption of smartphones has introduced new challenges to document copyright protection, prompting the emergence of Screen-Shooting Resilient Document Watermarking (SSRDW) technology. In recent years, underpainting-based SSRDW techniques have proven to be highly effective. However, after careful study, we find that existing methods fail to simultaneously meet four essential criteria for SSRDW: high imperceptibility, strong robustness, adaptability to text processing, and high efficiency. In this paper, we introduce an enhanced underpainting-based SSRDW approach capable of satisfying all four requirements. Our approach enhances imperceptibility by employing underpainting embedding methods independent of text content. Additionally, we introduce a fast resynchronization mechanism to improve time efficiency. Furthermore, we propose an enhanced watermark extraction method that enhances robustness and enables watermark retrieval even in scenarios involving text processing. Extensive experimental validation underscores the superior performance of our enhanced SSRDW method.

The popularity of digital devices and the importance of information which lies in text documents lead to the overflowing of screen-shooting attacks for text documents nowadays. So the robust screen-shooting watermarking for text documents is in great demand. However, the existing watermarking of text documents in traditional channels which is widely researched is not available under the huge distortion from screen-shooting attacks. To tackle this problem, in this letter, watermarking based on text document structures which can persist in both print-camera and screen-shooting processes is developed. Our method has two main advantages: 1) Extensive robustness. We define partial brightness integration accompanied with stroke separation method to embed watermark information on characters. For various documents with different fonts' styles, fonts' sizes and different languages' fonts, it shows great performances. Besides, for different shooting conditions such as different shooting distances and angles, the accuracy is also guaranteed. 2) Great imperceptibility. By introducing special divisional method and adaptive intensity, high visual ability is achieved. Both of these two merits are verified by massive experiments.

With the proliferation of smartphones, preserving the confidentiality of digital documents has become increasingly challenging. Document formats, such as PowerPoint (PPT), are particularly susceptible to unauthorized capture and leakage through smartphone cameras. In this letter, we propose a camera shooting resilient watermarking for PowerPoint presentation based on the PPT master layout backdrop, which exhibits two key properties. 1) Imperceptibility. We employ a difference-based embedding method on the PPT master layout backdrop to ensure good visual quality of the watermarked PPT. 2) Robustness. We design a distance-based selection method for embedding coefficients, ensuring the watermark's robustness under various shooting conditions. The experimental results demonstrate the robustness of our scheme against screen and projection shooting of PPT presentation, across diverse shooting distances, angles, and coverage levels of the PPT master layout backdrop.

According to the Buckets effect, the capacity of a bucket depends on the length of the shortest board. This principle also applies to social networking platform resilient (SNPR) image watermarking, which should be comprehensive and free from significant shortcomings. In the frequency domain, the watermarked region is formed using log-polar coordinate mapping (LPM) and has a ring-like structure. However, this structure cannot be stretched or compressed, and it causes a streaking effect at the edges of the watermarked image. These issues have been addressed in the proposed method. Specifically, an adaptive optimization framework is used to adjust the embedding strength and range of the watermark, and multiple synchronization strategies are adopted to correct flip and aspect ratio. Compared with state-of-the-art works, the proposed method significantly improves the imperceptibility of the watermarked image and its robustness to various distortions and lossy transmission on social networking platforms (SNPs).

Digital images are widely used nowadays, carrying a great deal of information. However, copyright infringement of digital images occurs from time to time which poses a threat to the rights and interests of copyright owners and the security of information content. To deal with such problems, in this paper, we propose an adaptive robust watermarking scheme to protect the copyright of color digital images. Spread spectrum watermark and two kinds of synchronization information are embedded in the luminance and chrominance channels of the color image, respectively. The synchronization information helps to restore geometric distortions. We also design a pre-quantization strategy to mitigate the distortions caused by social platforms. To achieve better imperceptibility, we propose an adaptive strategy based on the peculiarities of Human Visual System to adjust the strength of watermark residuals. Experimental results demonstrate that the proposed method is equipped with comprehensive and balanced robustness against common image processing, geometric distortions, unknown processing from social platforms and keeps the watermarked images with excellent imperceptibility simultaneously.