In this paper, we address the problem of 3D inpainting using exemplar-based method for point clouds. 3D inpainting is a process of filling holes or missing regions in the reconstructed 3D models. Typically, inpainting methods addressed in literature fill missing regions due to occlusions or inaccurate scanning of 3D models. However, we focus on scenarios involving naturally existing damaged models which are partly broken or incomplete in the artifacts at cultural heritage sites. We propose exemplar-based inpainting technique using region of interest (ROI)-based method to inpaint the missing regions of the damaged model. The ROI of a 3D model is represented as a set of Riemannian manifolds, and metric tensor and Christoffel symbols are used as geometric features to capture the inherent geometry. We then decompose the ROI into basic shape regions, namely, spherical, conical and cylindrical components, and identify the best-fit match for inpainting. Instead of using a single similar exemplar for inpainting, we select the most relevant best-fit region to fill the missing region from the basic shape regions library obtained from n similar exemplars. We demonstrate the performance of the proposed inpainting method on artifacts at UNESCO World heritage site Hampi temples, India with varying complexities and sizes for both synthetically generated holes and real missing regions in 3D objects.
The discovery of quasi-crystals has led to a great debate about their unusual structures. The big surprise is that these structures have been found in the world of Islamic art dating back several centuries. This latest discovery drew attention of scientists to propose several approaches for the comprehension of these structures by analyzing several quasi-periodic patterns spread around the Islamic World. In this work we will describe a simplified and general method for constructing a new variety of Islamic quasi-periodic patterns. The method builds Islamic quasi-periodic patterns based on a quasi-periodic tiling and a few intuitive parameters. Given a quasi-periodic tiling, the method divides its tiles (rhombs) into symmetric right triangles and constructs the template motifs within theme. The construction of these template motifs is achieved by a systematic and well organized process. The content of the tiles is obtained by application of mirror reflections to the constructed template motifs. Finally, the pattern is drawn by putting the constructed tiles' contents in the tiles of the tiling. To show the effectiveness of this generative method, examples of new quasi-periodic patterns will be presented.
Virtual environment has the potential to be used as a medium to facilitate cultural learning. However, this requires guidelines on how to design the environment. This article provides a conceptual framework that guides the design of a virtual environment that facilitates cultural learning for casual users. The exploratory sequential mixed-method design approach was used as the basis for the overall research design. Five studies involving experts and end users were performed to identify and evaluate the framework components. The framework consists of four important components: i) Information Design ii) Information Presentation iii) Navigation Mechanism and iv) Environment Setting, and outlines two types of design elements; basic elements which are essential for cultural learning to take place, and extended elements which provide options for enhanced user experience. Results from the framework evaluation suggest that the proposed design elements are useful in facilitating learning and that the experience of using the virtual environment affected the end users sense of awareness and appreciation towards heritage value and preservation.
This paper describes a prototype natural user interface, named the Intangible Musical Instrument, which aims to facilitate access to the knowledge of the performers that constitutes musical Intangible Cultural Heritage, using off-the-shelf motion capturing that is easily accessed by the public at large. This prototype is able to capture, model and recognize musical gestures (upper body including fingers) as well as to sonify them. The emotional status of the performer affects the sound parameters at the synthesis level. Intangible Musical Instrument is able to support both learning and performing/composing by providing to the user not only intuitive gesture control but also a unique user experience. In addition, the first evaluation of the Intangible Musical Instrument is presented, in which all the functionalities of the system are assessed. Overall, the results with respect to this evaluation were very promising.
We present a usage analysis of an interactive system for the exploration of highly detailed 3D models of a collection of protostoric mediterranean sculptures. In this system, after selecting the object of interest inside the collection, its detailed 3D model and associated information are presented at high resolution on a large vertical display controlled by a touch-enabled horizontal surface placed at a suitable distance in front of it. The indirect user interface combines an object-aware interactive camera controller with an interactive point-of-interest selector and is implemented within a scalable implementation based on multiresolution structures shared between the rendering and user interaction subsystems. The system has been installed in several temporary and permanent exhibitions, and has been extensively used by tens of thousands of visitors. We provide here a data-driven analysis of usage experience based on logs gathered during a 24 months period in four exhibitions in Archeological museums, for a total of over 75K exploration sessions. exploration user interfaces in future digital installations. The user study is particularly focused on individuating the main visitor behaviors during 3D exploration by employing tools for deriving interest measures on surfaces, and tools for clustering and knowledge discovery from high-dimensional data. The results highlight the main trends in visitor behavior during the interactive sessions, which can provide useful insights for the design of 3D exploration user interfaces in future digital installations.
In this paper, we propose Multi-Entity Bayesian Networks (MEBNs) as the probabilistic ontology framework for the analysis of the Tsamiko and Salsa dances. More specifically, the analysis has the objective of the dancer assessment with respect to both choreography execution accuracy and the synchronization of the dance movements with the musical rhythm. For this analysis task, we make use of the explicit, expert provided knowledge for the dance movements and their relations to the musical beat. Due to the complexity of this knowledge, the MEBNs were used as the probabilistic ontological framework in which the knowledge is formalized. The reason we opt for MEBNs for this task, explained thoroughly in this paper, is that they combine Bayesian and formal (first-order) logic into a single model. In this way, the Bayesian, probabilistic part of MEBNs was used to capture, using example data and training, the implicit part of the expert knowledge about the dances, i.e., this part of the knowledge that cannot be formalized and explicitly defined accurately enough. Moreover, we present in details the MEBN models we built for Tsamiko and Salsa, which is accomplished by using the expert provided explicit knowledge. Lastly, we conduct experiments that demonstrate the efficiency of the proposed MEBN based methodology we employ in order to achieve our analysis objectives. The results of the experiments demonstrate the superiority of MEBNs to conventional models, such as BNs, in terms of the dancer assessment accuracy.