Universität Stuttgart
Permanent URI for this communityhttps://elib.uni-stuttgart.de/handle/11682/1
Browse
7 results
Search Results
Item Open Access Philosophy of action and Its relationship to interactive visualisation and Molière’s theatre(2023) Feige, Daniel M.; Weiskopf, Daniel; Dickhaut, KirstenItem Open Access Impact of gaze uncertainty on AOIs in information visualisations(2022) Wang, Yao; Koch, Maurice; Bâce, Mihai; Weiskopf, Daniel; Bulling, AndreasGaze-based analysis of areas of interest (AOIs) is widely used in information visualisation research to understand how people explore visualisations or assess the quality of visualisations concerning key characteristics such as memorability. However, nearby AOIs in visualisations amplify the uncertainty caused by the gaze estimation error, which strongly influences the mapping between gaze samples or fixations and different AOIs. We contribute a novel investigation into gaze uncertainty and quantify its impact on AOI-based analysis on visualisations using two novel metrics: the Flipping Candidate Rate (FCR) and Hit Any AOI Rate (HAAR). Our analysis of 40 real-world visualisations, including human gaze and AOI annotations, shows that gaze uncertainty frequently and significantly impacts the analysis conducted in AOI-based studies. Moreover, we analysed four visualisation types and found that bar and scatter plots are usually designed in a way that causes more uncertainty than line and pie plots in gaze-based analysis.Item Open Access Visual analytics for nonlinear programming in robot motion planning(2022) Hägele, David; Abdelaal, Moataz; Oguz, Ozgur S.; Toussaint, Marc; Weiskopf, DanielNonlinear programming is a complex methodology where a problem is mathematically expressed in terms of optimality while imposing constraints on feasibility. Such problems are formulated by humans and solved by optimization algorithms. We support domain experts in their challenging tasks of understanding and troubleshooting optimization runs of intricate and high-dimensional nonlinear programs through a visual analytics system. The system was designed for our collaborators’ robot motion planning problems, but is domain agnostic in most parts of the visualizations. It allows for an exploration of the iterative solving process of a nonlinear program through several linked views of the computational process. We give insights into this design study, demonstrate our system for selected real-world cases, and discuss the extension of visualization and visual analytics methods for nonlinear programming.Item Open Access A depth-cueing scheme based on linear transformations in tristimulus space(2002) Weiskopf, Daniel; Ertl, ThomasWe propose a generic and flexible depth-cueing scheme which subsumes many well-known and new color-based depth-cueing approaches. In particular, it includes standard intensity depth-cueing and rather neglected pure saturation depth-cueing. A couple of new combinations and variations of depth cues are presented. Their usefulness is demonstrated in many different fields of application, reaching from non-photorealistic rendering to information visualization. In addition to cues based on a geometric concept of depth, an abstract visualization approach in the form of semantic depth-cueing is proposed. Our depth-cueing scheme is based on linear transformations in the 3D tristimulus space of colors and on weighted sums of colors. Since all of the required operations are supported by contemporary consumer graphics hardware, the depth-cueing scheme can be implemented without performance cutbacks. Therefore, any real-time rendering application can be enriched by sophisticated depth-cueing.Item Open Access Group diagrams for simplified representation of scanpaths(2023) Schäfer, Peter; Rodrigues, Nils; Weiskopf, Daniel; Storandt, SabineWe instrument Group Diagrams (GDs) to reduce clutter in sets of eye-tracking scanpaths. Group Diagrams consist of trajectory subsets that cover, or represent, the whole set of trajectories with respect to some distance measure and an adjustable distance threshold. The original GDs allow for an application of various distance measures. We implement the GD framework and evaluate it on scanpaths that were collected by a former user study on public transit maps. We find that the Fréchet distance is the most appropriate measure to get meaningful results, yet it is flexible enough to cover outliers. We discuss several implementation-specific challenges and improve the scalability of the algorithm. To evaluate our results, we conducted a qualitative study with a group of eye-tracking experts. Finally, we note that our enhancements are also beneficial within the original problem setting, suggesting that our approach might be applicable to various types of input data.Item Open Access Efficient and robust background modeling with dynamic mode decomposition(2022) Krake, Tim; Bruhn, Andrés; Eberhardt, Bernhard; Weiskopf, DanielA large number of modern video background modeling algorithms deal with computational costly minimization problems that often need parameter adjustments. While in most cases spatial and temporal constraints are added artificially to the minimization process, our approach is to exploit Dynamic Mode Decomposition (DMD), a spectral decomposition technique that naturally extracts spatio-temporal patterns from data. Applied to video data, DMD can compute background models. However, the original DMD algorithm for background modeling is neither efficient nor robust. In this paper, we present an equivalent reformulation with constraints leading to a more suitable decomposition into fore- and background. Due to the reformulation, which uses sparse and low-dimensional structures, an efficient and robust algorithm is derived that computes accurate background models. Moreover, we show how our approach can be extended to RGB data, data with periodic parts, and streaming data enabling a versatile use.Item Open Access mint : integrating scientific visualizations into virtual reality(2024) Geringer, Sergej; Geiselhart, Florian; Bäuerle, Alex; Dec, Dominik; Odenthal, Olivia; Reina, Guido; Ropinski, Timo; Weiskopf, DanielWe present an image-based approach to integrate state-of-the-art scientific visualization into virtual reality (VR) environments: the mint visualization/VR inter-operation system. We enable the integration of visualization algorithms from within their software frameworks directly into VR without the need to explicitly port visualization implementations to the underlying VR framework—thus retaining their capabilities, specializations, and optimizations. Consequently, our approach also facilitates enriching VR-based scientific data exploration with established or novel VR immersion and interaction techniques available in VR authoring tools. The separation of concerns enables researchers and users in different domains, like virtual immersive environments, immersive analytics, and scientific visualization, to independently work with existing software suitable for their domain while being able to interface with one another easily. We present our system architecture and inter-operation protocol (mint), an example of a collaborative VR environment implemented in the Unity engine (VRAUKE), as well as the integration of the protocol for the visualization frameworks Inviwo, MegaMol, and ParaView. Our implementation is publicly available as open-source software.