WSCG '2009: Poster Proceedings

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http://hdl.handle.net/11025/776

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Showing 1 - 13 out of 13 results

Efficient approach to direct B–spline surface rendering by a ray tracing
(Václav Skala - UNION Agency, 2009) Sisojevs, Aleksandrs; Glazs, Aleksandrs; Skala, Václav
There are different approaches to B-spline surface visualization by ray tracing methods. But these methods of computer graphics do not solve this task at an expected level. Therefore in this paper the authors propose to use a new approach for B-spline surface visualization by ray tracing method to render objects with high accuracy and quality
Invariant to transformations image retrieval from image databases using a boundary based description of object shape
(Václav Skala - UNION Agency, 2009) Stoeva, Mariana Tsvetanova; Bozhikova, Violeta Todorova; Skala, Václav
The basic problem of the methods for shape description of image objects is their dependence on the graphical transformations. In this paper we give boundary based method for shape description based on a multi-step criterion. We present a new approach for similarity shape retrieval from image database that achieves invariance of results with respect to transformations. We define and use a criterion to achieve invariant image object representation with respect to rotation. The approach includes original description of image objects shape of the type of multi-metric attribute stored in image database and a similarity distance definition for image retrieval processing that is invariant to reflection too. Our approach achieves results that are invariant with respect to arbitrary compositions of graphical transformations.
iGLANCE project: free-viewpoint 3D video
(Václav Skala - UNION Agency, 2009) Zinger, Svitlana; Ruijters, Daniel; de With, Peter H. N.; Skala, Václav
The iGLANCE project aims at researching the methods of receiving and rendering of free-view 3D-TV sequences. We describe the ongoing iGLANCE project and introduce the iGLANCE decoding and rendering system. It consists of free viewpoint video interpolation and coding. One of the key components of this system is view interpolation and its related challenges. There are two main application fields within iGLANCE: consumer and medical systems. In this article we discuss an example use case for a medical application that illustrates the need for the research and development in the iGLANCE framework.
Robotic visual and inertial gaze control using human learning
(Václav Skala - UNION Agency, 2009) Prado, José; Lobo, Jorge; Dias, Jorge; Skala, Václav
Humans make use of inertial and vision cues to determine ego-motion. Bayesian models can be used to represent the human behaviour to be used in a robot. An environment may be composed by an infinite number of variables and humans deal with some of them each time a motor decision needs to be taken.
Geometric modeling and computer graphics of kinematic ruled surfaces on the base of complex moving one axoid along another (one-sheet hyperboloid of revolution as fixed and moving axoids)
(Václav Skala - UNION Agency, 2009) Rachkovskaya, Galina S.; Kharabayev, Yuriy N.; Skala, Václav
In concordance with logical structure “Geometrical Model of Interaction of two contacted surfaces during the movement of one ruled surface along another – Corresponding Mathematical Transformations of Surfaces – New Kinematic Ruled Surfaces” [1-3] a new geometrical model of complex moving one axoid along another for the case of one-sheet hyperboloid of revolution as fixed and moving axoids has been proposed. The main condition of constructing kinematic ruled surfaces is that moving axoid contact with fixed axoid along one their common generating line in each of their positions during complex moving one axoid along another. A case when the axes of fixed and moving axoids are crossed (Fig. 1,2,3), has been considered in this research. Analytical development and computer graphics of the new kinematic surfaces are realized for three types of complex moving. (1)The outside surface of the fixed axoid is revolved slipping-free by the outside surface of the corresponding moving axoid (Fig. 1). (2)The interior surface of the fixed axoid is revolved slipping-free by the outside surface of the corresponding moving axoid (Fig. 2). (3)The outside surface of the fixed axoid is revolved slipping-free by the interior surface of the corresponding moving axoid (Fig. 3). Computer graphics of the constructed surfaces (Fig. 1a,2a,3a) have been performed by the previously developed software application.
Information transformation for point cloud
(Václav Skala - UNION Agency, 2009) Nishio, Koji; Takebayashi, Yusuke; Teshima, Yuji; Kanaya, Takayuki; Kobori, Ken-ichi; Skala, Václav
We propose a method of Information transformation for point cloud, which reduces information amount of three dimensional point data. Our method generates clusters and spiral chain lists. These chain lists are consists of three dimensional points. After that, we adopt a predictive encoding to compress these chain lists. In addition, we will show effectiveness of our method with same experimental results. In these experiments, our method reduces the information amount of point cloud coordinate to 31.7% of original model.
The force-map haptic rendering algorithm for drilling into volume
(Václav Skala - UNION Agency, 2009) Liu, Y.; Laycock, S. D.; Skala, Václav
With the developments of volume visualization technology for complex data sets comes new challenges in terms of user interaction and information extraction. Volume haptics has proven itself to be an effective way of extracting valuable information by providing an extra sense from which to perceive three dimensional data. The work presented in this paper introduces a Force-Map method that combines the benefits of the indirect and the direct haptic rendering approaches. Users can select from a variety of virtual tools to gain continuous and smooth force feedback during the drilling of volumetric data which increases the applicability of the approach.
Image deformation using radial basis function interpolation
(Václav Skala - UNION Agency, 2009) Kwon, Jung Hye; Lee, Byung Gook; Yoon, Jungho; Lee, Joon Jae; Skala, Václav
Image deformation technique is widely used in the field of computer animation, image editing, medical imaging, and other applications in 2D and 3D computer graphics. All the algorithms aim to provide simple user interface, most of which need the user to drag the control points, lines or polygon. The deformation process and the final position of the controlling points should be smooth and precise respectively, and it should also run in real-time. This paper provides a simple image deformation method using the radial basis function interpolation in approximation theory. Radial basis function is a very popular and convenient tool for data representation problems. The proposed method using radial basis function is fast and easy to use more than previous deformation methods. Experiments indicate that the algorithm is stable and well performed.
Seamless NPR video painting
(Václav Skala - UNION Agency, 2009) Kovács, Levente; Skala, Václav
The paper presents a method for automatic transformation of ordinary videos into non-photorealistic (NPR) graphical representations, for achieving painterly effects. The primary goal is the non-interactive transformation of videos, with the intended use as a service in community video databases (as an extension to content based retrieval). There are no restrictions on the types of videos. The main steps involve scene separation, color segmentation, foreground and focus area extraction, and vector graphical transformation of selected frames.
A visualization and management system for chat dialogues on 3D virtual avatars
(Václav Skala - UNION Agency, 2009) Ji, Seung-Hyun; Soo-Hyun, Park; Dong-Sung, Ryu; Cho, Hwan-Gue; Skala, Václav
Chat is one of basic features in current virtual world communication. So tracking of chat dialogue is an important issue. However most chat programs only provide textual history transcripts based on the temporal sequence, without any explicit relationship tags. In this poster, we propose a novel data structure, Chatting Flow Graph (CFG)[6] which keeps track of the all chatting dialogues among virtual agents. On this CFG we newly propose one visualization method for managing Chat Dialog efficiently and hierarchically.
Example based motion generation with efficient control
(Václav Skala - UNION Agency, 2009) Choung, Yujean; Kang, Kyung-Kyu; Dongho, Kim; Skala, Václav
This paper presents a motion generation technique for arbitrary morphologies with the user defined correspondences between joints. Users can define the controlling part in the source character and the part to be controlled in the target character in our system. To remove the restriction in the morphology of the target character, we use the pair of example posture sets. In our system, in order to provide the correspondence regardless of the number of joints, the deformed part in the target character is simplified into the direction vector. The final postures are then generated with the weighted sum of the examples. Our experimental results demonstrate that our approach can generate motions for various target characters and can control the user defined joints. Exploiting this correspondence between joints, our system can reflect the intention of animators efficiently and reduce their manual efforts.
A composition-based image retrieval using line feature
(Václav Skala - UNION Agency, 2009) Hwang, Jooyeon; Lim, Dongsup; Paik, Doowon; Skala, Václav
In this paper, we propose an image retrieval scheme that retrieves compositionally similar images with the query image from the line-used image set. To develop a new effective similarity measurement, we use line feature to discriminate in similarity, by investigating the relation between the value of the property and the degree of the compositional similarity. We have developed a similarity measure and compared effectiveness with a simple similarity measure in the sense of recall and precision. Our result proves that proposed scheme provides higher effectiveness.
3D navigation systems based on synthetic texturing
(Václav Skala - UNION Agency, 2009) Alizadehashrafi, Behnam; Rahman, Alias Abdul; Coors, Volker; Schulz, Thorsten; Skala, Václav
Navigation system is the order of the day to pilot people to their destination. This paper focuses on the uses of mobile devices such as PDA’s and smart phones without additional hardware to direct pedestrians based on synthetic texturing along with 3D modeling. Each facade is reconstructed by arraying small sized textures in respect to their geometries in different layers. In the process of texture generation cropping, rectifying, removing disturbing objects and exposure setting should be done in advance. Unlimited number of layers with different priorities and their horizontal and vertical pulse functions and texture files can be utilized for creating a simple square looking facade. Each 3D model is created by mapping the synthetic textures on the 3D geometries of each building’s 3D model. The processes to create the synthetic textures as well as their usage in mobiles’ context are described in detail in this paper.

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