WSCG 2014: Poster Papers Proceedings
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Item Particle systems-based riverbed modelling over a terrain with hardness layer(Václav Skala - UNION Agency, 2014) Warszawski, Korneliusz; Niekel, Slawomir; Skala, VáclavThis paper proposes a method that applies particle systems to simulate results of hydrological erosion caused by spout, like riverbeds. The terrain model is divided into two layers. The first one stores heights data (typical heightfield) while the second is reserved for hardness data. This data structure enables fast and simple implementation of terrain deformation. We present the construction of a particle system terrain modifier, its main attributes and how they influence the final product of the modelling process. The proposed technique behaves like in classical particle systems. It uses emitter as element that control starting location, direction and quantity of particles in a given simulation environment. We choose parameters for particles such as: the current position, directional angle, linear velocity, rotation angle, rotation velocity and the size which define its zone of influence for landscape modification processes. Each emitted particle is moving (rolling) over the surface of terrain structure making deformations at its current position. Scale of the modifications depends on particle parameters and landscape structure susceptibility for modifications process under the particle influence zone. The proposed method is not intended to simulate physically erosion process, but focuses on its results for exploitation in virtual environments in real-time simulations and rapid prototyping of virtual terrains.
Item VisNow – a Modular, Extensible Visual Analysis Platform(Václav Skala - UNION Agency, 2014) Nowinski, Krzysztof S.; Borucki, Bartosz; Skala, VáclavA new, dataflow driven, modular visual data analysis platform with extensive data processing and visualization capabilities is presented. VisNow is written in Java, easily extendable to incorporate new modules and module libraries. Dataflow networks built with the help of interactive network editor can be wrapped into stand-alone application for the end users.Item Survey on Automated LEGO Assembly Construction(Václav Skala - UNION Agency, 2014) Kim, Jae Woo; Kang, Kyung Kyu; Lee, Ji Hyoung; Skala, VáclavLEGO has been very popular toy in the world because it is attractive and fun to play with and stimulates one's creativity by providing means to conveniently assemble a variety of interesting shapes using the limited types of given bricks. However, it is hard for the beginners to design and assemble complex models they desire to make without instructions. Building a LEGO assembly manually usually requires a significant amount of trial-anderror. LEGO company therefore presented the LEGO construction problem in 1998 and in 2001. The problem statement is "Given any 3D body, how can it be built from LEGO bricks?" In this paper we will investigate the current research efforts to address the LEGO construction problem. We will review the problem definition, formulation, and a variety of approaches to solve the problem. We will discuss the data representations for input 3D polygonal models and the LEGO assembly structures, cost functions that will guide the search for the optimal solution, and various solution methods.Item Human-Computer Interaction Using Robust Gesture Recognition(Václav Skala - UNION Agency, 2014) Endler, Matthias; Lobachev, Oleg; Guthe, Michael; Skala, VáclavWe present a detector cascade for robust real-time tracking of hand movements on consumer-level hardware. We adapt existing detectors to our setting: Haar, CAMSHIFT, shape detector, skin detector. We use all these detectors at once. Our main contributions are: first, utilization of bootstrapping: Haar bootstraps itself, then its results are used to bootstrap the other filters; second, the usage of temporal filtering for more robust detection and to remove outliers; third, we adapted the detectors for more robust hand detection. The resulting system produces very robust results in real time. We evaluate both the robustness and the real-time capability.Item Parallel extraction hand vein biometric parameter’s using a low cost IR imaging system(Václav Skala - UNION Agency, 2014) Benziane, Sarah; Benyettou, Abdelkader; Merouane, Asmaa; Skala, VáclavThis paper presents a new and low cost approach to authenticate individuals using hand vein images. The proposed method is fully automated and employs palm dorsal hand vein images acquired from a low cost , near infrared contactless imaging; the aim of our work. In order to evaluate the system performance, a prototype was designed and a dataset of 34 persons from different ages above 20 and different gender, each has 10 images per person was acquired at different intervals, 5 images for left hand and 5 images for right hand. The vein detection process consists of an easy to implement a device that takes a snapshot of the subject’s veins under a source of infrared radiation at a specific wavelength. The system is able to detect veins but not arteries due to the specific absorption of infrared radiation in blood vessels. Almost any part of the body could be analyzed in order to extract an image of the vascular pattern but the hand and the fingers are preferred.Item Fast and Robust Tessellation-Based Silhouette Shadows(Václav Skala - UNION Agency, 2014) Milet, Tomáš; Kobrtek, Jozef; Zemčík, Pavel; Pečiva, Jan; Skala, VáclavThis paper presents a new simple, fast and robust approach in computation of per-sample precise shadows. The method uses tessellation shaders for computation of silhouettes on arbitrary triangle soup. We were able to reach robustness by our previously published algorithm using deterministic shadow volume computation. We also propose a new simplification of the silhouette computation by introducing reference edge testing. Our new method was compared with other methods and evaluated on multiple hardware platforms and different scenes, providing better performance than current state-of-the art algorithms. Finally, conclusions are drawn and the future work is outlined.Item Lane Marking Detection in Various Lighting Conditions using Robust Feature Extraction(Václav Skala - UNION Agency, 2014) Jang, Ho-Jin; Baek, Seung-Hae; Park, Soon-Yong; Skala, VáclavRobustly extracting the features of lane markings under different lighting and weather conditions such as shadows, glows, sunset and night is the a key technology of the lane departure warning system (LDWS). In this paper, we propose a robust lane marking feature extraction method. By useing the characteristics of the lane marking to detect candidate areas. The final lane marking features are extracted by first finding the center points of the lane marking in the candidate area then these center point pixels are labeled according to the intensity similarity along the direction of the vanishing point. The performance of the proposed method is evaluated by experiment at results using real world lane data.Item Adaptive Projection Displays: a low cost system for public interactivity(Václav Skala - UNION Agency, 2014) Dundas, Jenna; Wagner, Michael; Skala, VáclavInteractive digital public displays that track viewer’s position are currently inaccessible to the average consumer. Many tracking systems available on the market are prohibitively expensive and are out of scope for small business owners to purchase. A system can be devised by researching and testing various consumer level tracking technologies in a low cost and accessible manner. Microsoft’s Kinect in tandem with Unity3D offers a system that is straightforward to use and allows for ease of implementation. The resulting technique can be quickly carried out to create an interactive digital public display.Item Ocean wave simulation by the mix of FFT and Perlin Noise(Václav Skala - UNION Agency, 2014) Tian, Li; Skala, VáclavFor the application of ocean wave, a new height-field simulation method is proposed by the mix of FFT and Perlin Noise, and OpenSceneGraph (OSG) and VC++ 2008 are used to simulate realistic ocean wave. The method takes wind effects into consideration, and uses Philips model and Gauss random numbers to produce ocean wave spectrum, which is then transformed to wave height-field by FFT. Perlin Noise is overlaid to disturb the wave height to generate a vivid and random sea surface. Simulation results show the effectiveness of the proposed method.Item Spatter Tracking in Laser- and Manual Arc Welding with Sensor-level Pre-processing(Václav Skala - UNION Agency, 2014) Lahdenoja, Olli; Säntti, Tero; Laiho, Mika; Poikonen, Jonne; Skala, VáclavThis paper presents methods for automated visual tracking of spatters in laser- and manual arc welding. Imaging of the welding process is challenging due to extreme conditions of high radiated light intensity variation. The formation and the number of spatters ejected in the welding process are dependent on the parameters of the welding process, and can potentially be used to tune the process towards better quality (either on-line of offline). In our case, the spatter segmentation is based either on test on object elongatedness or Hough transform, which are applied on pre-processed image sequences captured by a high-speed smart camera. Part of the segmentation process (adaptive image capture and edge extraction) is performed on the camera, while the other parts of the algorithm are performed off-line in Matlab. However, our intention is to move the computation towards the camera or an attached FPGA.Item Connect-S: A Physical Visualization Through Tangible Interaction(Václav Skala - UNION Agency, 2014) Giang, Ken; Funk, Mathias; Skala, VáclavIn our current society, open data streams are more and more available through the Internet. This data can have an increasing impact on everyday life. Its full potential can, however, only reached through better integration and new interfaces. The goal of this project is to explore the possibilities of repurposing public information in a developing area of a large city in the Netherlands. Can we create a tangible interaction with use of physical visualization of these data streams? A series of prototypes have been made to develop a physical visualization through the method of research through design. Users were involved in expert panels and interviews to fine-tune and create a final prototype, Connect-S. The concept shows the opportunities of using physical visualization in connection with physical interaction for browsing and navigation.Item A Control Cluster Approach to Non-linear Deformation(Václav Skala - UNION Agency, 2014) Bukatov, A. A.; Gridchina, E. E.; Zastavnoy, D. A.; Skala, VáclavModeling plausible deformation of the objects has been an important task in computer animation and game design industry. The approach proposed in the paper deals with a polygonal mesh deformation splitting the vertices of the mesh into two types: cluster vertices and free vertices. With the user defining the shape of the mesh key areas with the help of cluster vertices, the algorithm takes advantage of non-linear geometric deformation for calculating free vertices position. The approach could be used both for creating a sequence of altered model shapes to produce a character animation (with the help of user-created control cluster data) and for visualizing some ecological processes.Item Visualizing multi-channel networks(Václav Skala - UNION Agency, 2014) Antemijczuk, Paweł; Magiera, Marta; Lehmann, Sune; Cuttone, Andrea; Larsen, Jakob Eg; Skala, VáclavIn this paper, we propose a visualization to illustrate social interactions, built from multiple distinct channels of communication. The visualization displays a summary of dense personal information in a compact graphical notation. The starting point is an abstract drawing of a spider’s web. Below, we describe the meaning of each data dimension along with the background and motivation for their inclusion. Finally, we present feedback provided by the users (31 individuals) of the visualization.Item A method of micro facial expression recognition based on dense facial motion data(Václav Skala - UNION Agency, 2014) Akagi, Yasuhiro; Kawasaki, Hiroshi; Skala, VáclavIn this paper, we propose a method for recognizing a micro expression which is a small motion appearing on a face by using a high density and high frame-rate 3D reconstruction method. Some studies report that the micro expressions are caused by the change of mental state. If we can recognize the micro expressions, this information could be useful for machines to understand the mental state of a human. With advancements of 3D reconstruction methods, methods have been proposed to reconstruct dynamic objects such as motions of a human’s body in high accuracy with high frame rate. Based on the data obtained from the high quality shape reconstruction method, the proposed method recognizes the micro expressions. To detect a part of the face where the micro-expressions are appeared, we propose an experimental estimation of the part. We also report a recognition rate of the change of the mental state using the experimental system.Item A new way of Rich Image Representation (VectorPixels)(Václav Skala - UNION Agency, 2014) Simons, Alain; Prakash, Edmond; Wood, James; Skala, VáclavFor decades the same technologies has been used for generating images on computer systems. On the one hand you have bitmap and on the other hand vector technology. Bitmap or pixel technology is mostly used for the representation of rich colour images. The other available imaging technology, vectors, is mainly used to present logos and drawings without photo realistic details. But both techniques have their disadvantages and advantages. In recent years a lot of research has been done to combine the advantages of both techniques in a comprehensive solution. Much research focused on giving a vector illustration a realistic picture look. There was no development from scratch and that is exactly what this paper wants to propose, an algorithm to invent the pixel again. By always applying new developments on existing technologies generating images became a mix of various techniques and a rather complex matter. With the use of VectorPixels (VP) the concept of a pixel will be redefined. In contrast with a pixel (Picture Element) a VectorPixel will be defined by a mathematical description and be resolution independent.Item Real time vehicle detection and tracking on multiple lanes(Václav Skala - UNION Agency, 2014) Kovačić, Kristian; Ivanjko, Edouard; Gold, Hrvoje; Skala, VáclavDevelopment of computing power and cheap video cameras enabled today’s traffic management systems to include more cameras and computer vision applications for transportation system monitoring and control. Combined with image processing algorithms cameras are used as sensors to measure road traffic parameters like flow, origindestination matrices, classify vehicles, etc. In this paper development of a system capable to measure traffic flow and estimate vehicle trajectories on multiple lanes using only one static camera is described. Vehicles are detected as moving objects using foreground and background image segmentation. Adjacent pixels in the moving objects image are grouped together and a weight factor based on cluster area, cluster overlapping area and distance between multiple clusters is computed to enable multiple moving object tracking. To ensure real time capabilities, image processing algorithm computation distribution between CPU and GPU is applied. Described system is tested using real traffic video footage obtained from Croatian highways.Item Polynomiography with non-standard iterations(Václav Skala - UNION Agency, 2014) Gdawiec, Krzysztof; Kotarski, Wiesław; Lisowska, Agnieszka; Skala, VáclavIn the paper the visualizations of some modifications applied to the Newton’s root finding of complex polynomials are presented. Namely, instead of the standard Picard iteration, several different iterative processes described in the literature, which we call as non-standard ones, were used. Following Kalantari, such visualizations are called polynomiographs. Polynomiographs are interesting from scientific, educational and artistic points of view. By the use of different iterations kinds we obtain quite new polynomiographs, in comparison to the standard Picard iteration, which look aesthetically pleasing. We present some polynomiographs for complex polynomial equation z3 -1 = 0 as examples. Polynomiographs were defined to graphically present dynamical behaviour of different iterative processes. But we are not interested in that. We are focused on polynomiographs from the artistic point of view. We believe that the new polynomiographs can be interesting as a source of aesthetic patterns created automatically. They can also be used to increase functionality of the existing polynomiography software.Item Method of discrete wavelet analysis of edges on the random background(Václav Skala - UNION Agency, 2014) Bezuglov, D. A.; Bezuglov, Yu. D.; Shvidchenko, S. A.; Skala, VáclavСurrently known algorithms suppose preliminary image filtering with consecutive solving of edges extraction problem. In the process of development of image filtering algorithms the a priori knowledge of distortion interference characteristics is also required. In practice in most of the cases such information is not available or is approximate. A new method of objects’ edges extraction in the images was developed, in the presence of distortion, by applying direct and inverse wavelet transformation. The results of mathematical modeling are provided. The proposed approach may be used in the course of development of digital picture processing systems, self-contained robots engineering, and under the surveillance conditions which complicate the registration process in the absence of a priori data about the background noise type.
