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 LDPC Scheme for Insertion/Deletion Correction in Multimedia Watermarking

ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, CaliforniaWe describe a simple and effective coding scheme for insertion/deletion channels. It is based on runlength coding which converts a class of insertion/deletion channels that have infinite memory into memoryless channels, which are much easier to handle. Runlength coding is then combined with powerful error correction low-density parity-check (LDPC) codes designed for memoryless channels. We consider a novel applications of this technique in multimedia watermarking using quantization index modulation operating on the three dimensional mesh vertices. The runlength LDPC coding recovers the data hidden in the vertices removed by the process of mesh simplification.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

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

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

This 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

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

This 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

Experimental Characterization of Signal Fades in Indoor Low-Power Wireless System

We perform statistical characterization of the wireless channel between the low-power transmitter and the receiver moving along the straight path in laboratory conditions. Our aim is to process the measurement results of the signal level variations and propose a model of fading suitable for analytical analysis. In addition, we will determine the appropriate parameter values for the proposed model that describes the statistics of signal intensity with random changes. Based on the measured values, in addition to the first order statistical characteristics, we will determine the second order characteristics, such as level crossing rate and average fade duration. These values are important in estimating the probability of error and ergodic capacity, as well as in the adequate design of the interleaver and error-correction codes.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 https://telemetry.org/contact-us/ if you have questions about items in this collection

Virtualization and Vice Versa: A New Procedural Model of the Reverse Virtualization for the User Behavior Tracking in the Virtual Museums

In this paper we present a method of the user behavior (UB) tracking by capturing and measuring user activities through the defined procedural model of the reverse virtualization process, implementing a proof of concept on a real case scenario: the Civic Gallery of Ascoli. In order to define the universal model of such “vice versa” virtual reality (VR) experience, we assigned particular descriptive functions (descriptors) to each interactive feature of the virtual user space. In this virtualization phase we store user interaction information locally using the web-socket streams protocol, ensuring complete control and manipulation of monitored functions. Our algorithm firstly collects the user interaction data and extracts the descriptors’ arguments into the indexed vector of corresponding variables. The next step determines UB pattern by solving the inverse descriptive functions in combination with an appropriate statistical analysis of gathered data. The final result of the proposed method is the repository of salient data that is used in the further user experience improvement, as well as to enable the museums to distinguish the most important points of the visitor interest in the virtual web tours. Our approach also offers a potential benefit of obtained results in an automatic calculation and prediction of UB patterns using artificial intelligence (AI