WSCG '2006: Posters proceedings
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Item A Multimodal User Interface Component for an Augmented Reality Mobile User Guidance System(Václav Skala - UNION Agency, 2006) Thum, Marco; Demiris, Thanos; Müller, Stefan; Skala, VáclavIn general, user interfaces should be intuitive, self-explanatory and adaptive to various user skills. Especially in augmented reality systems with complex interaction possibilities simple concepts are necessary to guide the user. Therefore, we extend the ideas of the traditional WIMP metaphor (Windows, Icons, Menus, Pointer) with the capabilities of multimodal interfaces where multiple ”human” communication channels are used as input data for navigation, orientation and interaction. In this work we will present the adaption of the user interface of an existing mobile augmented reality system for cultural heritage to multimodal interaction. We present the concepts that led us to the decision for the use of speech and capturing of hand movements by means of an inertial tracker, as well as the implementation aspects of the initial prototype. User evaluation trials will prove our approach.
Item A probabilistic approach for object recognition in a real 3-D office environment(Václav Skala - UNION Agency, 2006) Wünstel, Michael; Röfer, Thomas; Skala, VáclavThe scenario used focuses on object recognition in an office environment scene with the goal of classifying office equipment that is located on a table. The recognition system operates on three-dimensional point-clouds of objects on a loosely covered table where no previous information about the precise position of the table is given. As the point-clouds do not cover the complete objects and the data is noisy, especially for smaller objects a robust detection of special features is difficult. The workflow employed is a three step process: In a first step the table plane is detected and the point clouds of the objects are extracted from the surface. In the second step an object-oriented bounding-box is calculated to get the geometric dimensions, i.e. the properties measured. During a learning phase these simple features are used to calculate the parameters of Bayesian networks. The trained networks are used in the third step, i.e. the classification step. The dimensions of an unknown object form the input for a Bayesian network that yields the most probable object type.Item Automatic control point segmentation and localization for online camera calibration(Václav Skala - UNION Agency, 2006) Yuan, Chunrong; Skala, VáclavCamera calibration is an essential step for 3D object recognition and reconstruction. In this work, we propose a novel method for the automatic localization of control points and present a simple and yet robust online camera calibration system. First a planar calibration pattern with circular control points is designed. These points are then automatically segmented and localized by integrating information resulted from two complementary segmentation methods: region extraction and contour detection. After the calibration pattern has been shown to the system at a few locations, both the intrinsic and extrinsic camera parameters can be determined. The main advantage of this approach is that the metric measurement of the calibration pattern in the image plane is done purely automatically. We have implemented the whole system on a windows platform. Tests with USB cameras in different configurations and applications show the efficiency as well as the accuracy of the proposed approach.Item A simple anti-aliasing method for straight line drawing based on DSP platform(Václav Skala - UNION Agency, 2006) Wang, Dusheng; Toh, Hock Lye; Chen, Xiang; Yang, Fan; Skala, VáclavA simple and practical anti-aliasing method for a color straight line drawing is presented in this paper. The method has been applied in a DSP-based display system to remove the undesired jaggies occurred in the line drawing. The experimental results show that this method can produce a good visual effect on the low resolution display screen.Item ICP fitness analysis for 3D scan data matching(Václav Skala - UNION Agency, 2006) Vergeest, Joris S. M.; Song, Y.; Skala, VáclavFull automation of the registration of 3D scan data is, in general, still an unsolved problem. If supplementary data is provided, either by human assistance, or by additional devices, the registration process can be completed. We have analyzed under which conditions supplementary data is required, where the conditions are specified as subsets of configuration space. As a matching tool an ICP-based (iterative closest point) algorithm was deployed. A point in configuration space represents the amount of translation and rotation needed to obtain a match between 3D scans of two partial overlapping surfaces. As a function of the coordinates in configuration space, we determine the successfulness of the algorithm and hence whether additional information is required. Our shape matching method does not rely on pre-computation of surface invariants, nor on the identification of shape features. The possible application of the analysis results for practical 3D scanning purposes are described.Item Programming graphical objects and information in engineering drawings(Václav Skala - UNION Agency, 2006) Sokas, Algirdas; Skala, VáclavThis article introduces you to graphics programming in the AutoCAD environment. Using Visual Basic Application programming language prepared methods and procedures for solving these design problems: attaching, reading and fulfilling mathematical operations with information extended data of a graphical objects. All information about drawing in the AutoCAD system is in the drawing database. We will study it in Drawing Interchange Format (DXF), which is in many graphical systems. Algorithms are formed to attach database record information to a graphical object, to read the information from graphical objects and to create objects specification in the drawing. The prepared example shows framework drawing with specification and database with steel information written in Visual Basic Application programming language. The general purpose of this paper is to contribute to such a debate about possibility of Visual Basic Application graphics programming in engineering education..Item Matching for perceptual user interface(Václav Skala - UNION Agency, 2006) Rubio, Jose Maria Buades; López, Francisco Perales; Gómez, Javier Varona; Skala, VáclavIn this paper we describe a complete method for building a perceptual user interface in indoor uncontrolled environments. Overall system uses two calibrated cameras and does initialization: detects user, takes his/her measurements, builds a 3D-Model; and also performs matching/tracking for: trunk, head, left arm, right arm and hands.Item The creation of simple plants by the help of Python script in blender(Václav Skala - UNION Agency, 2006) Pokorný, Pavel; Skala, VáclavBlender is the open source software for 3D modeling, animation, rendering, post-production, interactive creation and playback. This software is fully free (with source code under GNU GPL) to use and distribute within any educational, professional or commercial environment. We can use some modeling methods implemented in Blender or Python scripts for the creation of our artwork. Blender has implemented an embedded Python interpreter, which allows it to run scripts written in that language. These scripts can use the Blender Python API to access the program's internals and greatly expand Blender's functions. In this paper, a simple Python script for the plants generation has been described and parameters and a random factor have been set.Item Combined filtering and key-frame reduction of motion capture data with application to 3DTV(Václav Skala - UNION Agency, 2006) Önder, Onur; Erdem, Çiğdem; Erdem, Tanju; Güdükbay, Uğur; Özgüç, Bülent; Skala, VáclavA new method for combined filtering and key-frame reduction of motion capture data is proposed. Filtering of motion capture data is necessary to eliminate any jitter introduced by a motion capture system. Key-frame reduction, on the other hand, allows animators to easily edit motion data by representing animation curves with a significantly smaller number of key frames. The proposed technique achieves key frame reduction and jitter removal simultaneously by fitting a Hermite curve to motion capture data using dynamic programming.Item A level-based geometric representation for the real-time simulation of NC machining processes(Václav Skala - UNION Agency, 2006) Moreno, Aitor; Toro, Carlos; Arizkuren, Iosu; Segura, Alvaro; Posada, Jorge; Novo, Marcelino; Falcón, Juanjo; Alcaín, Nieves; Skala, VáclavIn this paper a level-based geometric representation for a real-time material removal simulator is presented. It will be embedded into a commercial NC machine. The representation and its accompanying architecture have been used for the generation of an interactive simulation of a part being machined, taking the NC machine feedback as input. The simulator complies with the following restrictions: i) The virtual simulation and real machining process must be synchronized; ii) the internal representation of the objects must be as accurate as possible.Item Extension models of Cone tree visualizations to large scale knowledge base with semantic relations(Václav Skala - UNION Agency, 2006) Mizukoshi, Daisuke; Hori, Yukio; Tomonori, Gotoh; Skala, VáclavCone Tree is an appealing interactive 3D visualization model for hierarchical data structure. In any prior studies, data objects for visualization were constructed by only tree structure, which contained small number of data and nodes. Subject domains in real world for visualization studies have highly complicated relations, which cannot to be expressed in a few nodes and only hierarchical structure. In this paper, we proposed the visualization technique based on cone tree model to apply for a large-scale knowledge base, which has complicated data structure. The EDR Electronic Dictionary as a large-scale knowledge base was used in our study. The visualization system fro EDR was implemented with Java 3D. This paper describes the technique and the implemented system, and discusses some problems on the technique.Item A proposal from information visualization and human computer interaction point of view to the design of industrial interfaces(Václav Skala - UNION Agency, 2006) Larrea, Martín L.; Martig, Sergio R.; Castro, Silvia M.; Skala, VáclavIn this paper we show how the design of the interfaces present in a control room can benefit from the combination of concepts and techniques from Information Visualization and Human Computer Interaction (HCI). The process monitoring GUIs must present all the necessary information to control and change the state of the plant in a safety and productive way. Every person inside a control room must handle a high information volume and the exploration and analysis of this huge data volume has become increasingly difficult. This difficulty can lead to risk not only the production but also human lives. Information Visualization and HCI can help to deal with the flood of information.Item Sectional discrete curvature estimation based on the parabola(Václav Skala - UNION Agency, 2006) Hyoungseok, Kim; Hosook, Kim; Skala, VáclavThe local geometric properties such as curvatures and normal vectors play important roles in analyzing the local shape of objects. The result of the geometric operations such as mesh simplification and mesh smoothing is dependent on how to compute the curvature of vertices, because there is no its exact definition in meshes. In this paper, we indicate the fatal error in computing discrete sectional-curvatures by the previous discrete curvature estimations. Moreover, we present a new discrete sectional-curvature estimation to overcome the error, which is based on the parabolic interpolation and the geometric properties of Bezier curve.Item Conceptual design of a programmable geometry generator(Václav Skala - UNION Agency, 2006) Gumbau, Jesús; Chover, Miguel; Skala, VáclavCurrent real-time graphics architecture lacks a method for procedural geometry generation inside the GPU, so that the limited bus bandwidth doesn’t get involved. This document describes the conceptual design of a user-programmable geometry generator unit. This unit is capable of generating new geometry (vertices and indices) by processing a set of input data. This new geometry can be passed through the graphics pipeline to be rendered normally. This is done completely inside the GPU.Item Image reconstruction based on combination of wavelet decomposition, inpainting and texture synthesis(Václav Skala - UNION Agency, 2006) Chen, Huawei; Hagiwara, Ichiro; Skala, VáclavDigital inpainting provides a means for reconstruction of damaged portions of an image. Although the inpainting basics are straightforward, most inpainting techniques published in the literature are only suitable for remarkable small portion or smooth color image. In order to avoid such shortcomings, we present a new algorithm for digital reconstruction based on combination of wavelet decomposition, Surface-based/PDE-based inpainting and texture synthesis. In which, wavelet transform at first decomposes the image into high frequency and low frequency level parts. Subsequently, CSRBF which is generally used for surface interpolation or PDE-based inpainting is employed for low frequency level and texture synthesis is used for high frequency level. It results in that not only slightly portion but also the common blotched image can be reconstructed with high quality. Especially, our algorithm makes many difficult cases for other methods possible.Item Fast GPU-based normal map generation for simplified(Václav Skala - UNION Agency, 2006) Gumbau, Jesús; González, Carlos; Chover, Miguel; Skala, VáclavThis paper presents a method for normal map generation in the GPU. These normal maps are generated from a high resolution mesh and can be applied to any simplification of this mesh. This method takes advantage of the fact that there must be a correspondence between the texture coordinates of the low resolution mesh and the ones of the high resolution mesh. The proposed method for normal map generation is a brand-new method, since nowadays this process is being performed through software techniques. Hardware generation greatly reduces time in comparison with present-day solutions. Moreover, it allows for a dynamic modification of the map. There are some restrictions in relation to how texture coordinates must be distributed. However, this approach works perfectly with simplified models where these restrictions are fulfilled. This method makes use of vertex and pixel shaders for the normal map generation.Item Square root of 3 subdivision and 3 connected meshes with creases, boundaries and holes(Václav Skala - UNION Agency, 2006) Guillot, Olivier; Gourret, Jean-Paul; Skala, VáclavA project of surface meshing for still and animated images and associated software has been developed at L3i for several years. The software ([KG04]) implements a meshing technique of deformable objects based on triangular meshes or on polygons with only 3 connected vertices. In this paper, we present a technique of subdivision of triangular meshes and its adaptation to 3 connected meshes. The technique insures Cn continuity (n = 1 or 2), takes into account discontinuities such as creases, darts and boundaries, and allows approximation or interpolation of surfaces.Item Parametric discretization of supercover simplex(Václav Skala - UNION Agency, 2006) Fousse, Allan; Andres, Eric; Skala, VáclavWithin the framework of the development of a software which aims at unifying geometrical modelisation and image processing, based on both analytical and voxels representation of objects, we wish to extend this to parametrical objects. We focus, in this paper, on the study of parametrical simplexes and their relation with the discrete supercover model. Besides, we obtain a simple and incremental algorithm to run over nD discrete objects. This is also the basis of parametrical curves and surfaces studies.Item Measurement of medical parameters based on 3D surface models(Václav Skala - UNION Agency, 2006) Drapikowski, Pavel; Skala, VáclavIn medical diagnostics one need to perform quantitative analysis and measurements of 2D or 3D data. The length, angle, area of region, 3D surface area, volume are measure to determine medical parameters. This paper presents uncertainty estimation of 3D surface model created from object boundaries using CT, MRI series of images. Error propagation from CT images acquisition to the anatomical structure pointed (measured) by operator using 3D model cross-sections is introduced.Item Fast algorithm for cloud rendering using flat „3D textures”(Václav Skala - UNION Agency, 2006) Domański, Dariusz; Skala, VáclavThis paper presents an efficient method to render clouds in their natural dynamic (i.e.forming, dissipating, flowing). The algorithm uses flat „3D textures” to represent volumetric data. This is used to compute the amount of light reaching each voxel. The light values are computed in real time and then visualised using a slicing technique to enable on-line interaction with the cloud model.
