Ingmar S. Franke

Towards attention-centered interfaces: An aesthetic evaluation of perspective with eye tracking

The established method of representing three-dimensional space on a two-dimensional surface involves camera based, point of regard systems, comparable in design to the early “camera obscura”. However, geometrical limitations of such models lead to distortions of perspective when projected. This research investigated the influence of single- versus multi-perspectives on aesthetic choices within one image. A clear perceptual bias towards multi-perspective images was found, additionally supported by an eye tracking study. We propose that human users are more attracted by multi-perspective images, which emphasise the “semantic foci” of the scene, than by those being synthesized statically with only one geometrical prospect.

FlexiWall: Exploring Layered Data with Elastic Displays

By their deformable screen-materials elastic displays and projection screens provide physical three-dimensional interaction modalities like push, pull or bend. Compared with conventional Multi-Touch displays they offer an additional interaction dimension which can be used to explore data. In this article we describe the FlexiWall, a large elastic display, and several example applications using layered data sets. The exploration of several layers and correlations between these is not common to traditional user interfaces, where the interaction is often constrained to two dimensions. Therefore, new forms of interaction are introduced. We furthermore propose additional techniques and tools to explore layered data sets, e.g. utilizing transparent objects when interacting with elastic displays.

The eleventh finger: levels of manipulation in multi-touch interaction

Motivation -- Multi-touch surfaces offer a great potential for collaborative activities due to direct interaction and engaging user experiences. User input is no longer mediated through indirect devices like keyboard or mouse; instead, users can work in parallel or quickly alternate between interacting persons. So far, only standard manipulation gestures for rotating, scaling, and translation have been established as natural interaction with multi-touch devices. In this contribution, novel tools and paradigms to enrich multi-touch interaction are investigated. Research approach -- A workshop setting involving ten students, tutors, and business experts was used, in order to implement novel multi-touch prototypes over the course of two weeks. Findings/Design -- Five case studies have been implemented based on Microsoft® Surface technology, exploiting different levels of manipulation. Research limitations/Implications -- Exhaustive user studies concerning the presented model have not been conducted. Implications of the model are tentatively discussed, suggesting possible study designs for the future. Originality/Value -- Five levels of manipulation are formalized in a model that can be used to design and evaluate cognitive ergonomics of new multi-touch interfaces for collaborative activities. Take away message -- By implementing different levels of manipulation, multi-touch interfaces for collaborative interfaces can be made more powerful and enable users to easily achieve diversified results.

BiLL: an experimental environment for visual analytics

The field of Visual Analytics attempts to identify phenomena, guidelines, and algorithms to generate images suitable to communicate information efficiently and effectively. The benefit of using information visualizations is that the represented data can be quickly perceived and comprehended by the viewer. Research of novel visualization and interaction techniques in the context of three-dimensional computer graphics requires interactive computer systems. To this end, a component-oriented software framework is presented in this contribution. Bildsprache LiveLab (BiLL) allows independent implementation and combination of different components. Each component is responsible for various tasks in the context of investigating images of three-dimensional scenes. Two case studies covering multiperspective and color perspective illustrate the application of BiLL and its potential as an experimental environment for visualizing user-centered projections of three-dimensional scenes.

Aughanded Virtuality - the hands in the virtual environment

The leading motive of this poster is the utilization of the Augmented Virtuality technology and in particular the egocentric representation of real body parts in virtual and immersive environments. In this context, a prototypical application was developed, which superimposes the current view of the users hands on the virtual scene in real-time. This is achieved in form of a captured video stream. Advantages compared to virtual avatars arise from the detailed and individual representation of the users body and the saving of complex tracking hardware. Due to the integration of a toolbox, the visual appearance of the video overlay is highly customizable.

FlexiWall: Interaction in-between 2D and 3D Interfaces

Elastic displays offer new ways to interact with multi-dimensional data by using the deformation of the surface as a tool to explore, filter, structure, or manipulate data. While a large number of prototypes exist, a general concept for using this promising technology in real-world application domains has not been established. In this paper, we introduce a framework about elastic displays and their applications with reference to the interaction techniques they provide. We investigate the data applicable to elastic displays and the appropriate interaction techniques. Using this approach, it is possible to identify strengths and weaknesses of this technology regarding specific scenarios, to find commonalities to traditional user interfaces and to explore novel concepts for interaction.

FIGURE OUT PERSPECTIVES: PERCEPTUALLY REALISTIC AVATAR VISUALIZATION

Projection of three-dimensional space onto a twodimensional surface relies on the computer graphics camera based in design on the camera obscura. Geometrical limitations of this model lead to perspective distortions in wide-angle projections. Including the camera model, our approach is to involve the human perception in order to create a realistic spatial impression by a two-dimensional image. This paper discusses the influence of multi-perspective on three-dimensional computer graphics in virtual worlds based on the rules of perspective projection enhanced by characteristics of visual perception and techniques of Renaissance painting. The aim is to provide human-centered interfaces for an efficient and coherent communication of spatial information in virtual worlds to support avatarmediated interaction with its need for correct depiction of human figures concerning proportion and orientation. To this end, we explain an object-based and introduce a camera-based computer graphics procedure to prevent projective distortions and misalignments.

Saccade Detection and Processing for Enhancing 3D Visualizations in Real-Time

We describe the utilization of the visual phenomenon saccadic suppression for masking graphical modifications in real-time 3D visualizations in order to hide disruptive effects from the human visual perception. Consequently, a saccade detection algorithm was implemented, which delivers outcomes at runtime. Furthermore an appropriate plugin for a software framework for 3D visualization (cf. [8]) was developed. A demonstration scene illustrates the performance of our approach regarding saccade detection and processing. Test results revealed that 96,5% of the measured latencies undercut our determined threshold of 30ms.

A component-oriented framework for experimental computer graphics

This paper provides a report about a framework that uses a variety of standards. Readers interested in 3D computer graphics or component-oriented technology in C++ will find a report about the integration of various standards by relying on yet another standard for component-oriented software engineering. The highly successful Java standard called Open Services Gateway initiative (OSGi) is employed in a C++ implementation called Open Service Platform.The application of this standard, which is primarily focused on network-centric software and embedded systems, in the field of real-time 3D computer graphics, provides novel insights into the usability of the OSGi standard. Highlights Report about a framework with a strong focus on using standard solutions. Component-oriented technology in C++ used for computer graphics. Java standard OSGi exploited in a C++ implementation called Open Service Platform. Shows the benefits of a sound component standard in real-time 3D computer graphics. Novel insights into the general application of the OSGi standard.

Perception of Parallelism in Perspective Images

This contribution presents a study in which subjects are shown perspective views of simple shapes. The subject’s task was to decide whether the shape’s outlines were parallel to each other or not. It was observed that the subjects were strongly misled by perspective depth cues. Real parallels in orthographic projections were rarely detected. In contrast a minor convergent alignment of the outlines like in a linear perspective projection were perceived as parallel.