Ordered Statistics Vertex Extraction and Tracing Algorithm (OSVETA)

We propose an algorithm for identifying vertices from three dimensional (3D) meshes that are most important for a geometric shape creation. Extracting such a set of vertices from a 3D mesh is important in applications such as digital watermarking, but also as a component of optimization and triangulation. In the first step, the Ordered Statistics Vertex Extraction and Tracing Algorithm (OSVETA) estimates precisely the local curvature, and most important topological features of mesh geometry. Using the vertex geometric importance ranking, the algorithm traces and extracts a vector of vertices, ordered by decreasing index of importance.Comment: Accepted for publishing and Copyright transfered to Advances in Electrical and Computer Engineering, November 23th 201

Simplification Resilient LDPC-Coded Sparse-QIM Watermarking for 3D-Meshes

We propose a blind watermarking scheme for 3-D meshes which combines sparse quantization index modulation (QIM) with deletion correction codes. The QIM operates on the vertices in rough concave regions of the surface thus ensuring impeccability, while the deletion correction code recovers the data hidden in the vertices which is removed by mesh optimization and/or simplification. The proposed scheme offers two orders of magnitude better performance in terms of recovered watermark bit error rate compared to the existing schemes of similar payloads and fidelity constraints.Comment: Submitted, revised and Copyright transfered to IEEE Transactions on Multimedia, October 9th 201

A RUNLENGTH CODED ADAPTIVE QIM FOR THE CULTURAL HERITAGE 3D MODELS AUTHENTICATION

We describe a simple and effective quantization scheme for a digital 3D cultural heritage models authentication and watermarking. It is based on runlength coding which converts a class of deletion channels that have infinite memory into memoryless channels. We consider a novel application of this technique in multimedia watermarking and authentication using quantization index modulation operating on the three dimensional mesh vertices, which are invariant to geometric and topological transformation. Vector of the vertex indices is extracted from a huge digital 3D model using our powerful vertex extraction tool. The coding recovers the data hidden in the vertices removed by the process of mesh simplification

A Method for Determining the Shape Similarity of Complex Three-Dimensional Structures to Aid Decay Restoration and Digitization Error Correction

none5noThis paper introduces a new method for determining the shape similarity of complex three-dimensional (3D) mesh structures based on extracting a vector of important vertices, ordered according to a matrix of their most important geometrical and topological features. The correlation of ordered matrix vectors is combined with perceptual definition of salient regions in order to aid detection, distinguishing, measurement and restoration of real degradation and digitization errors. The case study is the digital 3D structure of the Camino Degli Angeli, in the Urbino’s Ducal Palace, acquired by the structure from motion (SfM) technique. In order to obtain an accurate, featured representation of the matching shape, the strong mesh processing computations are performed over the mesh surface while preserving real shape and geometric structure. In addition to perceptually based feature ranking, the new theoretical approach for ranking the evaluation criteria by employing neural networks (NNs) has been proposed to reduce the probability of deleting shape points, subject to optimization. Numerical analysis and simulations in combination with the developed virtual reality (VR) application serve as an assurance to restoration specialists providing visual and feature-based comparison of damaged parts with correct similar examples. The procedure also distinguishes mesh irregularities resulting from the photogrammetry process.openVasic I.; Quattrini R.; Pierdicca R.; Frontoni E.; Vasic B.Vasic, I.; Quattrini, R.; Pierdicca, R.; Frontoni, E.; Vasic, B

INFLUENCE OF LOCAL CURVATURE ESTIMATION ON THE 3D MESH TOPOLOGICAL AND GEOMETRIC STABILITY

The influence of curvature estimation on the 3D mesh topological and geometric stability is considered in this paper. It can be shown that, in the case of the most commonly used methods for local curvature estimation, the nontrivial calculus of curvature can lead to mistakes and treat as noise holders of shape. Therefore, new algorithms for solving problems in every step of these processes are proposed. The proposed algorithms are simple and quick from the viewpoint of the mathematical calculations, because they assume only a few extra steps in the algorithm of curvature evaluation. Besides, the new approach provides more accurate results then other approaches, and also reduces the possibility of 3D mesh geometry damages

DIGITAL SECURITY: 3D GEOMETRY PROTECTION OF THE AUTOMATICALLY RESTITUTED HISTORICAL BUILDINGS

This paper describes a novel method of data protection of the three-dimensional (3D) models that are obtained from automatic process of geometric restitution, using old two-dimensional (2D) architectural and artistic drawings. The first contribution of our research is the algorithm that includes several image processing steps, which are required in order to define walls, staircases and openings from the digitalized hand drawn architectural plans. The result of this step is detailed 3D model of the digitally processed historical building plans. The experimental confirmation of the algorithm accuracy is 3D model of the Chateau de Versailles, which is descripted by old hand drawings, dating between the end of the XVII and the XIX century. Next part of our research is theoretical and mathematical analysis of geometrical features of such 3D model that is a result of the image processing algorithm. The key-achievement of this part is new method of protecting the geometrical data using optimized adaptive Sparse Quantization Index Modulation (QIM) for embedding data bits into essential structure of the generated model. As a final result we present a secure authentication of the automatically restituted 3D model of the historically important artifact

Data Hiding and Its Applications

Data hiding techniques have been widely used to provide copyright protection, data integrity, covert communication, non-repudiation, and authentication, among other applications. In the context of the increased dissemination and distribution of multimedia content over the internet, data hiding methods, such as digital watermarking and steganography, are becoming increasingly relevant in providing multimedia security. The goal of this book is to focus on the improvement of data hiding algorithms and their different applications (both traditional and emerging), bringing together researchers and practitioners from different research fields, including data hiding, signal processing, cryptography, and information theory, among others

Neuro-OSVETA: A Robust Watermarking of 3D Meshes

Best and practical watermarking schemes for copyright protection of 3D meshes are required to be blind and robust to attacks and errors. In this paper, we present the latest developments in 3D blind watermarking with a special emphasis on our Ordered Statistics Vertex Extraction and Tracing Algorithm (OSVETA) algorithm and its improvements. OSVETA is based on a combination of quantization index modulation (QIM) and error correction coding using novel ways for judicial selection of mesh vertices which are stable under mesh simplification, and the technique we propose in this paper offers a systematic method for vertex selection based on neural networks replacing a heuristic approach in the OSVETA. The Neuro-OSVETA enables a more precise mesh geometry estimation and better curvature and topological feature estimation. These enhancements result in a more accurate identification of stable vertices resulting in significant reduction of deletion probability.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection