Anthony Tung Shuen Ho

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—A robust video watermarking scheme of the state-of-the-art video coding standard H.264/AVC is proposed in this brief. 2-D 8-bit watermarks such as detailed company trademarks or logos can be used as inconvertible watermark for copyright protection. A grayscale watermark pattern is first modified to accommodate the H.264/AVC computational constraints, and(More)
This paper presents a semi-fragile watermarking method for the automatic authentication and restoration of the content of digital images. Semi-fragile watermarks are embedded into the original image, which reflect local malicious tampering on the image. When tampered blocks are detected, the restoration problem is formulated as an irregular sampling(More)
Rendering a face recognition system robust is vital in order to safeguard it against spoof attacks carried out using printed pictures of a victim (also known as print attack) or a replayed video of the person (replay attack). A key property in distinguishing a live, valid access from printed media or replayed videos is by exploiting the information dynamics(More)
—A compact-size planar antenna with ultra-wideband (UWB) bandwidth and directional patterns is presented. The antenna can be fabricated on a printed circuit board (PCB). On one side of the PCB, it has a circular patch, and on the other side it has a slot-embedded ground plane with a fork-shaped feeding stub in the slot. Directional radiation is achieved by(More)
A novel H.264/AVC watermarking method is proposed in this paper. By embedding the robust watermark into DCT domain and the fragile watermark into motion vectors respectively , the proposed method can jointly achieve both copyright protection and authentication. Our scheme out-performs other video watermarking schemes on higher wa-termarking capacity(More)
Digital image content authentication addresses the problem of detecting any illegitimate modification on the content of images. To cope with this problem, a novel semifragile watermarking scheme using the pinned sine transform (PST) is presented in this paper. The watermarking system can localize the portions of a watermarked image that have been tampered(More)
In this paper, a robust and efficient digital image watermarking algorithm using the fast Hadamard transform (FHT) is proposed for the copyright protection of digital images. This algorithm can embed or hide an entire image or pattern as a watermark such as a company's logo or trademark directly into the original image. The performance of the proposed(More)
The use of a suitable perceptual model is necessary to minimize the visual distortion in the marked images, because minor modification to the pixels can be perceptible since the pixels are either black or white. In this paper, a new perceptual model is proposed for binary images that is useful for data hiding applications. In our model, the distortion that(More)
A novel semi-fragile digital watermarking method based on the slant transform (SLT) for image authentication and self-restoration is introduced in this paper. The watermark bits are embedded into the middle frequency region of each block after applying SLT of the original image. The original image is further compressed and then embedded into the least(More)
This paper proposed a novel and efficient scheme to authenticate the H.264/AVC video. The scheme makes an accurate usage of the tree-structured motion compensation, motion estimation and Lagrangian optimization of the standard. Authentication information is embedded strictly based on the best mode decision strategy in the sense that if undergone any spatial(More)