A novel watermarking algorithm for three-dimensional point-cloud models based on vertex curvature

A new blind watermarking scheme for three-dimensional point-cloud models is proposed based on vertex curvature to achieve an appropriate trade-off between transparency and robustness. The root mean square curvature of local set of every vertex is first calculated for the three-dimensional point-cloud model and then the vertices with larger root mean square curvature are used to carry the watermarking information; the vertices with smaller root mean square curvature are exploited to establish the synchronization relation between the watermark embedding and extraction. The three-dimensional point-cloud model is divided into ball rings, and the watermarking information is inserted by modifying the radial radii of vertices within ball rings. Those vertices taking part in establishing the synchronization relation do not carry the watermarking information; therefore, the synchronization relation is not affected by the embedded watermark. Experimental results show the proposed method outperforms other well-known three-dimensional point-cloud model watermarking methods in terms of imperceptibility and robustness, especially for against geometric attack.

Research on Digital Watermarking Algorithm for Anti-geometric Attack

For the problem that the traditional digital watermarking algorithm is less robustness against geometric attacks, this paper introduces the related content of digital watermarking technology, which combs digital watermarking technology, digital watermarking attack technology and digital watermarking evaluation method, and summarizes the improved algorithms proposed in recent years. Next, the traditional wavelet transform algorithm and the improved algorithm based on DCT transform are selected for comparison experiments. The latter combines Arnold scrambling and SVD decomposition, which has better shear resistance. Finally, combined with the research status, the future research focus of digital watermarking algorithm is prospected.

Randon and Ridgelet Transformation Applicaton in Image Digital Watermark

Propose a digital watermark algorithm that can be resisted geometric attack, in order to enhance the capacity to resist attacks such as rotation, use the 0° angle Randon transformation as the reference vector, estimate and correct the rotation transformation of the carrier image, recover the watermark synchronization. when watermark is embedded, perform wavelet transform on original image and blocked the LF sub-band, perform the Ridgelet transformation on each block; change two-value watermark to one-dimension, embedded the watermark bit into the Maximum energy direction of Ridgelet. The simulation results show that the algorithm can effective resist various attacks such as noise, filtering, compression, rotation, shearing and scaling etc, and the ability of resist various attacks is robust.