Document Server@UHasselt
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Repository of the University of Hasselt containing publications in the fields of statistics, computer science, information strategies and material from the Institute for behavioural sciences.
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1.
Open Issues for the development of 3D Multimodal User Interfaces from an MDE perspectiv - DE BOECK, Joan; Gonzales Calleros, J.M.; CONINX, Karin; Vanderdonckt, J.
Given its current state of the art, Model-Based UI Development (MBDUI) is able to fulfill the major requirements of desktop and mobile applications, such as form-based user interfaces that adapt to the actual context of use. More recent research deals with the development of 3D interactive multimodal environments. Though user-centered design is more and more driving the design of these environments, less attention is devoted to the development proc-esses than to interactive tools supporting isolated phases in the realization process. In this paper we describe our findings when considering model-based development of 3D multimodal applica-tions in the context of model-driven...
2.
Interactive Acquisition and Rendering of Humans - DE DECKER, Bert; BEKAERT, Philippe
We present a distributed model-based system for interactive acquisition and rendering of free viewpoint video of humans. All current model-based systems are offline. Online systems which can be used for free viewpoint video of humans use few low resolution cameras or use only silhouette information while the method presented here can cope with high resolution images and uses both color and silhouette information. A person is captured with multiple synchronized and calibrated digital video cameras attached to a cluster of pcs. At interactive rates, the shape of the person is estimated and the person can be rendered from novel viewpoints....
3.
Robust Stereo Aggregation with Large Windows - GERRITS, Mark; BEKAERT, Philippe
We present a new window-based stereo matching algorithm which
focuses on robust outlier rejection during aggregation. The main difficulty
for window-based methods lies in determining the best window shape and size
for each pixel. Working from the assumption that depth discontinuities occur
at colour boundaries, we segment the reference image and consider all window
pixels outside the image segment that contains the pixel under consideration
as outliers and greatly reduce their weight in the aggregation process. We
developed a variation on the recursive moving average implementation to keep
processing times independent from window size. Together with a robust
matching cost and the combination of the left and right disparity...
4.
A method for the verification of haptic algorithms - DE BOECK, Joan; RAYMAEKERS, Chris; CONINX, Karin
The number of haptic algorithms has been growing over the past few years. However, little research has been performed in evaluating these algorithms. This paper provides both a theoretical framework and a practical discussion of how the correctness and performance of force-feedback algorithms can be verified. The practical discussion is necessary as the theoretical framework proves that an infinite number of cases should be considered when evaluating a haptic algorithm. However, using statistical techniques, this evaluation can be performed within a reasonable frame of time. The evaluation method in this paper has itself been validated by evaluating two algorithms. From...
5.
Highly stylised drawn animation - DI FIORE, Fabian; VAN REETH, Frank; Patterson, J.; Willis, P.
In this paper we argue for our NPAR system as an effective 2D alternative to most of NPR research which is focused on frame coherent stylised rendering of 3D models. Our approach gives a highly stylised look to images without the support of 3D models, and yet they still behave as though animated by drawing, which they are.
First, a stylised brush tool is used to freely draw extreme poses of characters. Each character is built up of 2D drawn brush strokes which are manually grouped into layers. Each layer is assigned its place in a drawing hierarchy called a Hierarchical...
6.
The quantized kd-tree: efficient ray tracing of compressed point clouds - HUBO, Erik; MERTENS, Tinne; HABER, Tom; BEKAERT, Philippe
Both ray tracing and point-based representations provide means to efficiently display very complex 3D models. Computational efficiency has been the main focus of previous work on ray tracing point-sampled surfaces. For very complex models efficient storage in the form of compression becomes necessary in order to avoid costly disk access. However, as ray tracing requires neighborhood queries, existing compression schemes cannot be applied because of their sequential nature. This paper introduces a novel acceleration structure called the quantized kd-tree, which offers both efficient traversal and storage. The gist of our new representation lies in quantizing the kd-tree splitting plane coordinates....
7.
Telebuddies on the move: social stitching to enhance the networked gaming experience - THYS, Kristof; HUYPENS, Steven; CONINX, Karin
In this paper we report on our work to enable "laid-back" social interactions using television as a primary interaction medium and mobile devices that participate as a secondary medium. By integrating semantic web techniques with interactive television we were able to create smart applications that can run as extensions of television shows and stimulate groups of users to communicate. Participants are teamed up to play along with a television show. Teams are composed based on common ground, which can be shared interests as well as shared characteristics that can be found between the users. Participating is possible using a set-top...
8.
Telebuddies: Social Stitching with Interactive Television - LUYTEN, Kris; THYS, Kristof; HUYPENS, Steven; CONINX, Karin
In this paper we report on our work to enable laid-back social interactions using television as a primary interaction medium. By integrating semantic web techniques with interactive television we were able to create smart applications that can run as extensions of television shows and stimulate groups of users to communicate. Groups are based on the shared characteristics that can be found for subsets of spectators. Communication between spectators is brought about at two levels: direct communication like instant messaging and indirect communication like cooperating in a team to win a quiz. Our system does not necessarily require a new television...
9.
A Generic Approach for Multi-Device User Interface Rendering with UIML - LUYTEN, Kris; THYS, Kristof; VERMEULEN, Jo; CONINX, Karin
We present a rendering engine for displaying graphical user interfaces
on multiple devices. The renderer interprets a standardized XML-based
user interface description language: the User Interface Markup Language
(UIML). A generic architecture for the renderer is defined so that
deployment of the engine on different devices implies only little effort.
We show that our rendering engine can be used on iDTV set-top boxes,
mobile phones, PDAs and desktop PCs, and smoothly integrates with
both local and remote application logic. As a test bed for the UIML
specification we also explore support for extensions to UIML that enable
the user interface designer to maximize accessibility and target multiple
devices and different...
10.
ARCHIE - Designing for interaction: socially-aware museum handheld guides - LUYTEN, Kris; VAN LOON, Heleen; GABRIELS, Kris; TEUNKENS, Daniel; CONINX, Karin; Manshoven, E.
We present ARCHIE, a interdisciplinary research project of the Expertise Centre for Digital Media (University of Hasselt) and the Gallo-Roman Museum of Tongeren (Province of Limburg) which aims to discover how a handheld guide can be used to enhance the museum learning experience. Because we stress on the important role of social interaction as a prerequisite for intellectual, social, personal and cultural development; one of the main objectives of the ARCHIE project is to encourage and stimulate interaction with the museum, the PDA and fellow visitors. Designing for interaction however asks for a mental switch. At this point, we developed...
11.
Towards an extensible context ontology for ambient intelligence - Preuveneers, D.; VAN DEN BERGH, Jan; Wagelaar, D.; Georges, A.; Rigole, P.; CLERCKX, Tim; Berbers, Y.; CONINX, Karin; Jonckers, V.; De Bosschere, K.
To realise an Ambient Intelligence environment, it is paramount that applications can dispose of information about the context in which they operate, preferably in a very general manner. For this purpose various types of information should be assembled to form a representation of the context of the device on which aforementioned applications run. To allow interoperability in an Ambient Intelligence environment, it is necessary that the context terminology is commonly understood by all participating devices. In this paper we propose an adaptable and extensible context ontology for creating context-awaxe computing infrastructures, ranging from small embedded devices to high-end service platforms....
12.
SOFA: Software for Observing Force-feedback Algorithms - RAYMAEKERS, Chris; CONINX, Karin
Over the past few years, haptic algorithms have advanced considerably. However, no standard evaluation method exists, which allows researchers to compare their results in an objective manner. This paper elaborates on an evaluation method for haptic algorithms. As this method makes use of user input, an experiment was conducted to define how to the evaluation method should be applied.
In order to allow researchers to apply the evaluation method, a C++ library was developed: SOFA, Software for Observing Force-feedback Algorithms. This library can be used in haptic rendering libraries, which allows developers to provide their own haptic device implementation.
Finally, the SOFA...
13.
Uniting cartoon textures with computer assisted animation - VAN HAEVRE, William; DI FIORE, Fabian; VAN REETH, Frank
We present a novel method to create perpetual animations from a small set of given keyframes. Existing approaches either are limited to re-sequencing large amounts of existing image/video data, or to interpolating vector based drawings.Our approach benefits from several ideas and techniques from video textures, computer-assisted animation and motion graphs. It combines the re-sequencing of existing material with the automatic generation of new data. Furthermore, the animator can interfere with the animation process at each arbitrary moment.First, a given set of keyframes is used to automatically generate a set of in-betweens. The amount of in-betweens required, depends on a distance...
14.
Are existing metaphors in virtual environments suitable for haptic interaction - DE BOECK, Joan; RAYMAEKERS, Chris; CONINX, Karin
Each computer application is designed to allow users to perform one or more tasks. As those tasks can be very diverse in nature and as they can become very complex with a lot of degrees of freedom, metaphors are used to facilitate the execution of those tasks. At present several metaphors exist, all with their strengths and weaknesses.
Our research focuses on haptic interaction and how this can support the user in accomplishing tasks within the virtual environment. This can be realised by integrating force feedback in a fully multimodal communication with e.g. speech and gestures. Therefore, suitable metaphors have to...
15.
Profile-aware multi-device interfaces: an MPEG-21-based approach for accessible user interfaces - LUYTEN, Kris; THYS, Kristof; CONINX, Karin
The wide diversity of consumer devices has led to new methodologies and techniques to make digital content available over a broad range of devices with minimal effort. In particular the design of the interactive parts of a system has been the subject of a lot of research efforts because these parts are the most visible and are critical for the usability (and thus use) of a system. One thing that is missing in many current approaches is the ability to combine these new methodologies and techniques with a user-centric approach to ensure preferences from and requirements for a specific user...
16.
Using UML 2.0 and profiles for modelling context-sensitive user interfaces - VAN DEN BERGH, Jan; CONINX, Karin
Significant work has been established in both the HCI community and the software engineering community to structure and to rationalize development within their respective fields using abstractions that are crystallized into a limited set of models. Each of these models gives a precise definition of one of the aspects of the design. In this position paper we present a more detailed analysis describing how UML 2.0 and its light-weight extension mechanism, profiles, can be used to model both the dynamic and structural aspects of context-sensitive user interfaces.
17.
A comparison of different techniques for haptic cloth rendering - RAYMAEKERS, Chris; CUPPENS, Erwin; CONINX, Karin; VANACKEN, Lode
In haptic cloth rendering, a user can interact with a cloth simulation, while feeling forces that relate to the cloth topology. This can be realized by combining two existing techniques: cloth simulation and collision detection. However, several design choices must be made in order to have a realistic simulation while maintaining real-time rendering times. This paper discusses the techniques needed for haptic cloth rendering and assesses which techniques are best suited in order to realize the haptic simulation.
18.
Integrating UIML, task, dialogs with layout patterns for multi-device user interface design - LUYTEN, Kris; CONINX, Karin; Abrams, M.
HCI Patterns represent design knowledge that can be reapplied in different situations where the same type of tasks
has to be represented. This can be done easily if the devices that support these tasks do not differ in input and output
capabilities. A pattern described with the traditional Alexandrian notation does not contain sufficient information as
is to be flexible enough to support multi-device user interface design and automatically adapt according to the
context of use. On the other hand, a degree of plasticity for a pattern can be defined that determines the varying
contexts where the pattern can be applied. We show how a...
19.
The Effect of Display Size on Navigation in a Virtual Environment - RAYMAEKERS, Chris; DE BOECK, Joan; DE WEYER, Tom; CONINX, Karin
When navigating in a virtual environment, a user has to solve several problems, such as finding the target and moving towards this target. A variation of navigation metaphors have been defined, each of them with its own merits and problems. On the other hand, different output devices, such as a regular computer monitor or a large display can be used in order to visualize the virtual world. The characteristics of these devices, such as the field of view, also influence the user's performance. In this paper, we investigate how different combinations of navigation metaphors and output devices influence the efficiency...
20.
Interactive Systems on the Road: Development of Vehicle User Interfaces for Failure Assistance - HOUBEN, Geert; VAN DEN BERGH, Jan; LUYTEN, Kris; CONINX, Karin
In-vehicle interactive systems are usually specialized systems that rely on a particular set of hardware and are designed to support the driver in reaching a destination with his/her vehicle. Since the importance of these systems, especially when they are built to support the driver while driving, a lot of research already has been done concerning usability and safety. In contrast, interactive systems that support the automotive after sales market have generated much less attention. Here, other aspects need to be emphasized such as the failure type and complexity, means for information visualization and communication, and connectivity. We present an overview...
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