EuroVisShort2016

Permanent URI for this collection

Groningen, the Netherlands, 6-10 June 2016
Flow Visualization
Analysis of Error in Interpolation-Based Pathline Tracing
Jennifer Chandler, Roxana Bujack, and Kenneth I. Joy
Error Estimates for Lagrangian Flow Field Representations
Mathias Hummel, Roxana Bujack, Kenneth I. Joy, and Christoph Garth
Crystal Glyph: Visualization of Directional Distributions Based on the Cube Map
Xin Tong, Huijie Zhang, Chris Jacobsen, Han-Wei Shen, and Patrick McCormick
Detecting and Visualizing Rip Current Using Optical Flow
Shweta Philip and Alex Pang
Visualizing Flow Fields Using Fractal Dimensions
Han-Wei Shen, Ross Vasko, and Rephael Wenger
Medical Visualization
LMML: Initial Developments of an Integrated Environment for Forensic Data Visualization
Malik Olivier Boussejra, Noboru Adachi, Hideki Shojo, Ryohei Takahashi, and Issei Fujishiro
Visualization for Understanding Uncertainty in Activation Volumes for Deep Brain Stimulation
Brad E. Hollister, Gordon Duffley, Chris Butson, Chris Johnson, and Paul Rosen
Fast 3D Thinning of Medical Image Data based on Local Neighborhood Lookups
Tobias Post, Christina Gillmann, Thomas Wischgoll, and Hans Hagen
VarVis: Visualizing Anatomical Variation in Branching Structures
Noeska Smit, Annelot Kraima, Daniel Jansma, Marco deRuiter, Elmar Eisemann, and Anna Vilanova
Towards Visual Mega-Analysis of Voxel-based Measurement in Brain Cohorts
Guohao Zhang, Peter Kochunov, Elliot Hong, Hamish Carr, and Jian Chen
Multidimensional and Geospatial Visualization
Space Bundling for Continuous Parallel Coordinates
Gregorio Palmas and Tino Weinkauf
SpaceCuts: Making Room for Visualizations on Maps
Juri Buchmüller, Dominik Jäckle, Florian Stoffel, and Daniel A. Keim
Visualizing Time-Dependent Data Using Dynamic t-SNE
Paulo E. Rauber, Alexandre X. Falcão, and Alexandru C. Telea
Interactive Web-based Visualization for Accessibility Mapping of Transportation Networks
Alexander Schoedon, Matthias Trapp, Henning Hollburg, and Jürgen Döllner
Manifold Visualization via Short Walks
Yang Zhao, Sotirios Tasoulis, and Teemu Roos
Design, Evaluation, and Applications
Judgment Error in Pie Chart Variations
Robert Kosara and Drew Skau
Using Icicle Trees to Encode the Hierarchical Structure of Source Code
Ivan Bacher, Brian Mac Namee, and John D. Kelleher
Visualization of Publication Impact
Eamonn Maguire, Javier Martin Montull, and Gilles Louppe
Spiral Theme Plot
Shenghui Jiang, Shiaofen Fang, and Shaun Grannis
Cavity and Pore Segmentation in 3D Images with Ambient Occlusion
Daniel Baum and Jürgen Titschack
Human Computer Interaction
Classic Techniques in New Domains: An Alternative Recipe
Megan Monroe
Clarifying Hypotheses by Sketching Data
Mariana Marasoiu, Alan F. Blackwell, Advait Sarkar, and Martin Spott
IN2CO - A Visualization Framework for Intuitive Collaboration
Franca-Alexandra Rupprecht, Bernd Hamann, Christian Weidig, Jan C. Aurich, and Achim Ebert
CompaRing: Reducing Costs of Visual Comparison
Christian Tominski
Analytic Behavior and Trust Building in Visual Analytics
Dominik Sacha, Ina Boesecke, Johannes Fuchs, and Daniel A. Keim

BibTeX (EuroVisShort2016)
@inproceedings{
10.2312:eurovisshort.20161152,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Analysis of Error in Interpolation-Based Pathline Tracing}},
author = {
Chandler, Jennifer
and
Bujack, Roxana
and
Joy, Kenneth I.
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161152}
}
@inproceedings{
10.2312:eurovisshort.20161153,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Error Estimates for Lagrangian Flow Field Representations}},
author = {
Hummel, Mathias
and
Bujack, Roxana
and
Joy, Kenneth I.
and
Garth, Christoph
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161153}
}
@inproceedings{
10.2312:eurovisshort.20161154,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Crystal Glyph: Visualization of Directional Distributions Based on the Cube Map}},
author = {
Tong, Xin
and
Zhang, Huijie
and
Jacobsen, Chris
and
Shen, Han-Wei
and
McCormick, Patrick
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161154}
}
@inproceedings{
10.2312:eurovisshort.20161156,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Visualizing Flow Fields Using Fractal Dimensions}},
author = {
Shen, Han-Wei
and
Vasko, Ross
and
Wenger, Rephael
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161156}
}
@inproceedings{
10.2312:eurovisshort.20161157,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
LMML: Initial Developments of an Integrated Environment for Forensic Data Visualization}},
author = {
Boussejra, Malik Olivier
and
Adachi, Noboru
and
Shojo, Hideki
and
Takahashi, Ryohei
and
Fujishiro, Issei
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161157}
}
@inproceedings{
10.2312:eurovisshort.20161155,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Detecting and Visualizing Rip Current Using Optical Flow}},
author = {
Philip, Shweta
and
Pang, Alex
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161155}
}
@inproceedings{
10.2312:eurovisshort.20161158,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Visualization for Understanding Uncertainty in Activation Volumes for Deep Brain Stimulation}},
author = {
Hollister, Brad E.
and
Duffley, Gordon
and
Butson, Chris
and
Johnson, Chris
and
Rosen, Paul
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161158}
}
@inproceedings{
10.2312:eurovisshort.20161160,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
VarVis: Visualizing Anatomical Variation in Branching Structures}},
author = {
Smit, Noeska
and
Kraima, Annelot
and
Jansma, Daniel
and
deRuiter, Marco
and
Eisemann, Elmar
and
Vilanova, Anna
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161160}
}
@inproceedings{
10.2312:eurovisshort.20161159,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Fast 3D Thinning of Medical Image Data based on Local Neighborhood Lookups}},
author = {
Post, Tobias
and
Gillmann, Christina
and
Wischgoll, Thomas
and
Hagen, Hans
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161159}
}
@inproceedings{
10.2312:eurovisshort.20161163,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
SpaceCuts: Making Room for Visualizations on Maps}},
author = {
Buchmüller, Juri
and
Jäckle, Dominik
and
Stoffel, Florian
and
Keim, Daniel A.
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161163}
}
@inproceedings{
10.2312:eurovisshort.20161162,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Space Bundling for Continuous Parallel Coordinates}},
author = {
Palmas, Gregorio
and
Weinkauf, Tino
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161162}
}
@inproceedings{
10.2312:eurovisshort.20161161,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Towards Visual Mega-Analysis of Voxel-based Measurement in Brain Cohorts}},
author = {
Zhang, Guohao
and
Kochunov, Peter
and
Hong, Elliot
and
Carr, Hamish
and
Chen, Jian
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161161}
}
@inproceedings{
10.2312:eurovisshort.20161164,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Visualizing Time-Dependent Data Using Dynamic t-SNE}},
author = {
Rauber, Paulo E.
and
Falcão, Alexandre X.
and
Telea, Alexandru C.
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161164}
}
@inproceedings{
10.2312:eurovisshort.20161166,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Manifold Visualization via Short Walks}},
author = {
Zhao, Yang
and
Tasoulis, Sotirios
and
Roos, Teemu
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161166}
}
@inproceedings{
10.2312:eurovisshort.20161165,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Interactive Web-based Visualization for Accessibility Mapping of Transportation Networks}},
author = {
Schoedon, Alexander
and
Trapp, Matthias
and
Hollburg, Henning
and
Döllner, Jürgen
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161165}
}
@inproceedings{
10.2312:eurovisshort.20161167,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Judgment Error in Pie Chart Variations}},
author = {
Kosara, Robert
and
Skau, Drew
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161167}
}
@inproceedings{
10.2312:eurovisshort.20161169,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Visualization of Publication Impact}},
author = {
Maguire, Eamonn
and
Montull, Javier Martin
and
Louppe, Gilles
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161169}
}
@inproceedings{
10.2312:eurovisshort.20161168,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Using Icicle Trees to Encode the Hierarchical Structure of Source Code}},
author = {
Bacher, Ivan
and
Namee, Brian Mac
and
Kelleher, John D.
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161168}
}
@inproceedings{
10.2312:eurovisshort.20161170,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Spiral Theme Plot}},
author = {
Jiang, Shenghui
and
Fang, Shiaofen
and
Grannis, Shaun
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161170}
}
@inproceedings{
10.2312:eurovisshort.20161172,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Classic Techniques in New Domains: An Alternative Recipe}},
author = {
Monroe, Megan
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161172}
}
@inproceedings{
10.2312:eurovisshort.20161171,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Cavity and Pore Segmentation in 3D Images with Ambient Occlusion}},
author = {
Baum, Daniel
and
Titschack, Jürgen
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161171}
}
@inproceedings{
10.2312:eurovisshort.20161173,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Clarifying Hypotheses by Sketching Data}},
author = {
Marasoiu, Mariana
and
Blackwell, Alan F.
and
Sarkar, Advait
and
Spott, Martin
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161173}
}
@inproceedings{
10.2312:eurovisshort.20161175,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
CompaRing: Reducing Costs of Visual Comparison}},
author = {
Tominski, Christian
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161175}
}
@inproceedings{
10.2312:eurovisshort.20161176,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
Analytic Behavior and Trust Building in Visual Analytics}},
author = {
Sacha, Dominik
and
Boesecke, Ina
and
Fuchs, Johannes
and
Keim, Daniel A.
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161176}
}
@inproceedings{
10.2312:eurovisshort.20161174,
booktitle = {
EuroVis 2016 - Short Papers},
editor = {
Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
}, title = {{
IN2CO - A Visualization Framework for Intuitive Collaboration}},
author = {
Rupprecht, Franca-Alexandra
and
Hamann, Bernd
and
Weidig, Christian
and
Aurich, Jan C.
and
Ebert, Achim
}, year = {
2016},
publisher = {
The Eurographics Association},
ISSN = {-},
ISBN = {978-3-03868-014-7},
DOI = {
10.2312/eurovisshort.20161174}
}

Browse

Recent Submissions

Now showing 1 - 26 of 26
  • Item
    EuroVis Short Papers 2016: Frontmatter
    (Eurographics Association, 2016) Enrico Bertini; Niklas Elmqvist; Thomas Wischgoll;
  • Item
    Analysis of Error in Interpolation-Based Pathline Tracing
    (The Eurographics Association, 2016) Chandler, Jennifer; Bujack, Roxana; Joy, Kenneth I.; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Chandler et al. [COJ15] presented interpolation-based pathline tracing as an alternative to numerical integration for advecting tracers in particle-based flow fields and showed that their method has lower error than a numerical integration-based method for particle tracing. We seek to understand the sources of the error in interpolation-based pathline tracing. We present a formal analysis of the theoretical bound on the error when advecting pathlines using this method. We characterize the error experimentally using characteristics of the flow field such as neighborhood change, flow divergence, and trajectory length. Understanding the sources of error in an advection method is important to know where there may be uncertainty in the resulting analysis. We find that for interpolation-based pathline tracing the error is closely related to the divergence in the flow field.
  • Item
    Error Estimates for Lagrangian Flow Field Representations
    (The Eurographics Association, 2016) Hummel, Mathias; Bujack, Roxana; Joy, Kenneth I.; Garth, Christoph; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Computing power outpaces I/O bandwidth in modern high performance computers, which leads to temporal sparsity in flow simulation data. Experiments show that Lagrangian flow representations (where pathlines are retrieved from short-time flow maps using interpolation and concatenation) outperform their Eulerian counterparts in advection tasks under these circumstances. Inspired by these results, we present the theoretical estimate of the Lagrangian error for individual pathlines, depending on the choice of temporal as well as spatial resolution. In-situ, this measure can be used to steer the output resolution and post-hoc, it can be used to visualize the uncertainty of the pathlines. To validate our theoretical bounds, we evaluate the measured and the estimated error for several example flow fields.
  • Item
    Crystal Glyph: Visualization of Directional Distributions Based on the Cube Map
    (The Eurographics Association, 2016) Tong, Xin; Zhang, Huijie; Jacobsen, Chris; Shen, Han-Wei; McCormick, Patrick; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    High resolution simulations are capable of generating very large vector fields that are expensive to store and analyze. In ad- dition, the velocity fields generated from some particle simulations are not stored on spatial grids, which become difficult to visualize using some traditional vector field visualization methods such as streamlines. Furthermore, the noise and/or uncer- tainty contained in the data often affects the quality of visualization by producing visual clutter that interferes with both the interpretation and identification of important features. An alternative approach is to store the distribution of many vector ori- entations and visualize the distribution with 3D glyphs. This paper presents the cube map histogram, a new data structure for storing the distribution of three-dimensional vector directions. We also present a glyph called the crystal glyph that effectively visualizes the directional distribution using OpenGL cube map textures. By placing crystal glyphs in the 3D data space, users can identify the directional distribution of the regional vector field from the shape and color of the glyph without visual clutter.
  • Item
    Visualizing Flow Fields Using Fractal Dimensions
    (The Eurographics Association, 2016) Shen, Han-Wei; Vasko, Ross; Wenger, Rephael; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Streamlines are a popular way of visualizing flow in vector fields. A major challenge in flow field visualization is selecting the streamlines to view. Rendering too many streamlines clutters the visualization and makes features of the field difficult to identify. Rendering too few streamlines causes viewers to completely miss features of the flow field not rendered. The fractal dimension of a streamline represents its space-filling properties. To identify complex or interesting streamlines, we build a regular grid of scalar values which represent the fractal dimension of streamlines around each grid vertex. Vortices and turbulent regions are often associated with regions of high fractal dimension. We use this scalar grid both to filter streamlines by fractal dimension and to identify and visualize regions containing vortices and turbulence. We describe an interactive tool which allows for quick streamline selection and visualization of regions containing vortices and turbulence.
  • Item
    LMML: Initial Developments of an Integrated Environment for Forensic Data Visualization
    (The Eurographics Association, 2016) Boussejra, Malik Olivier; Adachi, Noboru; Shojo, Hideki; Takahashi, Ryohei; Fujishiro, Issei; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Fighting against crime is paramount to any society, maybe more today than ever before. Tools to fight and elucidate crime are rooted in forensic science. Through the autopsy of a body, we can answer a whole range of questions as to how death happened and come up with explanations and counter-measures so that the same dire circumstance does not happen again. Now, because the reports collecting the data are written manually, the recording of the data collected through traditional autopsy still is a cumbersome, time-consuming task. Our framework, based on a mark-up language (that we dubbed ''LMML'') to store, describe and arrange forensic data, aims at overcoming those issues. Our contribution is twofold: the design of the syntax and semantics of LMML, and the conception of an interface to create, edit, analyse or query files written in that language. Thus, this framework allows quicker, smoother input of forensic data, for better automation and visualization thereof, so that they can be used by medical examiners, investigators, as well as judicial courts.
  • Item
    Detecting and Visualizing Rip Current Using Optical Flow
    (The Eurographics Association, 2016) Philip, Shweta; Pang, Alex; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Rip current are fast moving and narrow currents that are strongest near the beach. They are dangerous not only for novice but also experienced swimmers. Once caught in the current, the flow of the water pulls the person away from the beach. Many people in panic try to swim against the current and end up drowning due to exhaustion since these currents are usually faster than the speed at which one can swim. They have led to the drowning deaths of more than 100 beachgoers each year in United States alone [USL16]. For a knowledgeable person, these rip-currents are fairly easy to spot. But they are a threat to most people who are unaware of rip-currents or who do not know how to identify them. In this paper, we discuss a novel approach that uses optical flow to detect rip currents and then visualize them in an intuitive manner.
  • Item
    Visualization for Understanding Uncertainty in Activation Volumes for Deep Brain Stimulation
    (The Eurographics Association, 2016) Hollister, Brad E.; Duffley, Gordon; Butson, Chris; Johnson, Chris; Rosen, Paul; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    We have created the Neurostimulation Uncertainty Viewer (nuView or nView) tool for exploring data arising from deep brain stimulation (DBS). Simulated volume of tissue activated (VTA), using clinical electrode placements, are recorded along with patient outcomes in the Unified Parkinson's disease rating scale (UPDRS). The data is volumetric and sparse, with multi-value patient results for each activated voxel in the simulation. nView provides a collection of visual methods to explore the activated tissue to enhance understanding of electrode usage for improved therapy with DBS.
  • Item
    VarVis: Visualizing Anatomical Variation in Branching Structures
    (The Eurographics Association, 2016) Smit, Noeska; Kraima, Annelot; Jansma, Daniel; deRuiter, Marco; Eisemann, Elmar; Vilanova, Anna; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Anatomical variations are naturally-occurring deviations from typical human anatomy. While these variations are considered normal and non-pathological, they are still of interest in clinical practice for medical specialists such as radiologists and transplantation surgeons. The complex variations in branching structures, for instance in arteries or nerves, are currently visualized side-by-side in illustrations or expressed using plain text in medical publications. In this work, we present a novel way of visualizing anatomical variations in complex branching structures for educational purposes: VarVis. VarVis consists of several linked views that reveal global and local similarities and differences in the variations. We propose a novel graph representation to provide an overview of the topological changes. Our solution involves a topological similarity measure, which allows the user to select variations at a global level based on their degree of similarity. After a selection is made, local topological differences can be interactively explored using illustrations and topology graphs. We also incorporate additional information regarding the probability of the various cases. Our solution has several advantages over traditional approaches, which we demonstrate in an evaluation.
  • Item
    Fast 3D Thinning of Medical Image Data based on Local Neighborhood Lookups
    (The Eurographics Association, 2016) Post, Tobias; Gillmann, Christina; Wischgoll, Thomas; Hagen, Hans; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Three-dimensional thinning is an important task in medical image processing when performing quantitative analysis on structures, such as bones and vessels. For researchers of this domain a fast, robust and easy to access implementation is required. The Insight Segmentation and Registration Toolkit (ITK) is often used in medical image processing and visualization as it offers a wide range of ready to use algorithms. Unfortunately, its thinning implementation is computationally expensive and can introduce errors in the thinning process. This paper presents an implementation that is ready to use for thinning of medical image data. The implemented algorithm evaluates a moving local neighborhood window to find deletable voxels in the medical image. To reduce the computational effort, all possible combinations of a local neighborhood are stored in a precomputed lookup table. To show the effectiveness of this approach, the presented implementation is compared to the performance of the ITK library.
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    SpaceCuts: Making Room for Visualizations on Maps
    (The Eurographics Association, 2016) Buchmüller, Juri; Jäckle, Dominik; Stoffel, Florian; Keim, Daniel A.; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Visual map features like streets, rail tracks, or rivers do not provide enough space to visualize multiple attributes on them. Related approaches to solve space issues distort the map with lenses, apply distortion techniques to the map geometry, or employ three dimensional visualizations. All these techniques come at the cost of distortion or overlapping of relevant map features or they even produce overlap of visualized data. In this paper, we present SpaceCuts, a technique to generate additional space for data visualization on maps that does not distort the map and introduces only minimal overlap by cutting the map along a geographic structure and pulling the resulting areas apart. Besides introducing the basic technique, we discuss possible interactions, further extensions, application scenarios, and outline potential future research.
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    Space Bundling for Continuous Parallel Coordinates
    (The Eurographics Association, 2016) Palmas, Gregorio; Weinkauf, Tino; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Continuous Parallel Coordinates (CPC) are a visualization technique used to perform multivariate analysis of different scalar fields defined on the same domain. While classic Parallel Coordinates draws a line for each sample point, a CPC visualization uses a density-based representation. An interesting possibility for the classic method is to highlight higher-dimensional clusters using edge bundling, where each line becomes a spline bent towards the centroid of the cluster. This often leads to expressive, illustrative visualizations. Unfortunately, bundling lines is not possible for CPC, as they are not involved in this method. In this paper, we propose a deformation of the visualization space for Continuous Parallel Coordinates that leads to similar results as those obtained through classic edge bundling. We achieve this by performing a curved-profile transformation in image space. The approach lends itself to a computationally lightweight GPU implementation. Furthermore, we provide intuitive interactions with the bundled clusters. We show several examples of our technique applied to a commonly available data set.
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    Towards Visual Mega-Analysis of Voxel-based Measurement in Brain Cohorts
    (The Eurographics Association, 2016) Zhang, Guohao; Kochunov, Peter; Hong, Elliot; Carr, Hamish; Chen, Jian; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    We present a visualization prototype for comparative analysis of factional anisotropy (FA) distributions constructed from threedimensional (3D) brain diffusion tensor imaging (DTI) in brain cohorts. The prototype lets brain scientists examine metaanalysis (the pooled analysis of multiple smaller trials or multi-site studies) results for identifying differences in cohorts. Interactive side-by-side bar charts show multiple statistical results of FA comparisons in regions of interest (ROIs) defined by user-chosen atlas. An occlusion-free two-dimensional (2D) semantic merge tree further displays the global distribution of FA values. Two histograms on each tree arc reveal voxel-based FA distributions represented by that arc branch in cohorts. Interaction techniques support brushing-and-linking of local and global ROIs queries. ROIs can be defined from atlas or select through interaction. We report validation results in a case study and an interview.
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    Visualizing Time-Dependent Data Using Dynamic t-SNE
    (The Eurographics Association, 2016) Rauber, Paulo E.; Falcão, Alexandre X.; Telea, Alexandru C.; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Many interesting processes can be represented as time-dependent datasets. We define a time-dependent dataset as a sequence of datasets captured at particular time steps. In such a sequence, each dataset is composed of observations (high-dimensional real vectors), and each observation has a corresponding observation across time steps. Dimensionality reduction provides a scalable alternative to create visualizations (projections) that enable insight into the structure of such datasets. However, applying dimensionality reduction independently for each dataset in a sequence may introduce unnecessary variability in the resulting sequence of projections, which makes tracking the evolution of the data significantly more challenging. We show that this issue affects t-SNE, a widely used dimensionality reduction technique. In this context, we propose dynamic t-SNE, an adaptation of t-SNE that introduces a controllable trade-off between temporal coherence and projection reliability. Our evaluation in two time-dependent datasets shows that dynamic t-SNE eliminates unnecessary temporal variability and encourages smooth changes between projections.
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    Manifold Visualization via Short Walks
    (The Eurographics Association, 2016) Zhao, Yang; Tasoulis, Sotirios; Roos, Teemu; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Visualizing low-dimensional non-linear manifolds underlying high-dimensional data is a challenging data analysis problem. Different manifold visualization methods can be characterized by the associated definitions of proximity between highdimensional data points and score functions that lead to different low-dimensional embeddings, preserving different features in the data. The geodesic distance is a popular and well-justified metric. However, it is very hard to approximate reliably from finite samples especially between far apart points. In this paper, we propose a new method called Minimap. The basic idea is to approximate local geodesic distances by shortest paths along a neighborhood graph with an additional penalizing factor based on the number of steps in the path. Embedding the resulting metric by Sammon mapping further enhances the local structures at the expense of long distances that tend to be less reliable. Experiments on real-world benchmarks suggest that Minimap can robustly visualize manifold structures.
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    Interactive Web-based Visualization for Accessibility Mapping of Transportation Networks
    (The Eurographics Association, 2016) Schoedon, Alexander; Trapp, Matthias; Hollburg, Henning; Döllner, Jürgen; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Accessibility is a fundamental aspect in transportation, routing, and spare-time activity planning concerning traveling in modern cities. In this context, interactive web-based accessibility-map visualization techniques and systems are important tools for provisioning, exploration, analysis, and assessment of multi-modal and location-based travel time data and routing information. To enable their effective application, such interactive visualization techniques demands for flexible mappings with respect to user-adjustable parameters such as maximum travel times, the types of transportation used, or used color schemes. However, traditional approaches for web-based visualization of accessibility-maps do not allow this degree of parametrization without significant latencies introduced by required data processing and transmission between the routing server and the visualization client. This paper presents a novel web-based visualization technique that allows for efficient client-side mapping and rendering of accessibility data onto transportation networks using WebGL and the OpenGL transmission format. A performance evaluation and comparison shows the superior performance of the approach over alternative implementations.
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    Judgment Error in Pie Chart Variations
    (The Eurographics Association, 2016) Kosara, Robert; Skau, Drew; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Pie charts and their variants are prevalent in business settings and many other uses, even if they are not popular with the academic community. In a recent study, we found that contrary to general belief, there is no clear evidence that these charts are read based on the central angle. Instead, area and arc length appear to be at least equally important. In this paper, we build on that study to test several pie chart variations that are popular in information graphics: exploded pie chart, pie with larger slice, elliptical pie, and square pie (in addition to a regular pie chart used as the baseline). We find that even variants that do not distort central angle cause greater error than regular pie charts. Charts that distort the shape show the highest error. Many of our predictions based on the previous study's results are borne out by this study's findings.
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    Visualization of Publication Impact
    (The Eurographics Association, 2016) Maguire, Eamonn; Montull, Javier Martin; Louppe, Gilles; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Measuring scholarly impact has been a topic of much interest in recent years. While many use the citation count as a primary indicator of a publications impact, the quality and impact of those citations will vary. Additionally, it is often difficult to see where a paper sits among other papers in the same research area. Questions we wished to answer through this visualization were: is a publication cited less than publications in the field?; is a publication cited by high or low impact publications?; and can we visually compare the impact of publications across a result set? In this work we address the above questions through a new visualization of publication impact. Our technique has been applied to the visualization of citation information in INSPIREHEP (www.inspirehep.net), the largest high energy physics publication repository.
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    Using Icicle Trees to Encode the Hierarchical Structure of Source Code
    (The Eurographics Association, 2016) Bacher, Ivan; Namee, Brian Mac; Kelleher, John D.; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    This paper presents a study which evaluates the use of a tree visualisation (icicle tree) to encode the hierarchical structure of source code. The tree visualisation was combined with a source code editor in order to function as a compact overview to facilitate the process of comprehending the global structure of a source code document. Results from our study show that providing an overview visualisation led to an increase in accuracy and a decrease in completion time when participants performed counting tasks. However, in locating tasks, the presence of the visualisation led to a decrease in participants' performance.
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    Spiral Theme Plot
    (The Eurographics Association, 2016) Jiang, Shenghui; Fang, Shiaofen; Grannis, Shaun; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    We introduce a new visualization method for temporal data, Spiral Theme Plot, by combining ThemeRiver method, spiral patterns, and scatter plot technique. Similar to ThemeRiver, data in different categories (themes) are visualized in different bands, but also in a spiral pattern. Themes are stacked along a spiral curve, which represent the time axis. Individual data points are plotted within the regions of the themes, with various visual features. In addition to showing the overall theme patterns over time, this approach also shows plotting patterns within the themes. Compared to ThemeRiver, Spiral Theme Plot can accommodate longer time axis, and more importantly, can provide periodic patterns that are typically not available in ThemeRiver.
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    Classic Techniques in New Domains: An Alternative Recipe
    (The Eurographics Association, 2016) Monroe, Megan; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    In this paper, we adapt the classic technique of depicting a process as a structured workflow to suit the standard recipe. Cooking can be thought of as a small data, big user task. A single recipe encompasses only a small amount of information, but is utilized across a large user base. Our goal was to understand and measure the benefits of tailoring the presentation of a recipe to suit a specific faction of users. As such, our more technical rendering was paired with a technically proficient user base, resulting in dramatic gains in both the speed and accuracy with which the information was interpreted. These benefits serve to motivate our continued work towards automatically translating recipes into a structured data format that can be easily reconfigured into this and other representations of the information to enable a more customized experience across a large and varied user base.
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    Cavity and Pore Segmentation in 3D Images with Ambient Occlusion
    (The Eurographics Association, 2016) Baum, Daniel; Titschack, Jürgen; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Many natural objects contain pores and cavities that are filled with the same material that also surrounds the object. When such objects are imaged using, for example, computed tomography, the pores and cavities cannot be distinguished from the surrounding material by considering gray values and texture properties of the image. In this case, morphological operations are often used to fill the inner region. This is efficient, if the pore and cavity structures are small compared to the overall size of the object and if the object's shape is mainly convex. If this is not the case, the segmentation might be very difficult and may result in a lot of noise. We propose the usage of ambient occlusion for the segmentation of pores and cavities. One nice property of ambient occlusion is that it generates smooth scalar fields. Due to this smoothness property, a segmentation based on those fields will result in smooth boundaries at the pore and cavity openings. This is often desired, particularly when dealing with natural objects.
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    Clarifying Hypotheses by Sketching Data
    (The Eurographics Association, 2016) Marasoiu, Mariana; Blackwell, Alan F.; Sarkar, Advait; Spott, Martin; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Discussions between data analysts and colleagues or clients with no statistical background are difficult, as the analyst often has to teach and explain their statistical and domain knowledge. We investigate work practices of data analysts who collaborate with non-experts, and report findings regarding types of analysis, collaboration and availability of data. Based on these, we have created a tool to enhance collaboration between data analysts and their clients in the initial stages of the analytical process. Sketching time series data allows analysts to discuss expectations for later analysis. We propose function composition rather than freehand sketching, in order to structure the analyst-client conversation by independently expressing expected features in the data. We evaluate the usability of our prototype through two small studies, and report on user feedback for future iterations.
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    CompaRing: Reducing Costs of Visual Comparison
    (The Eurographics Association, 2016) Tominski, Christian; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Comparison is a frequent task when analyzing data. In visualization, comparison tasks are naturally carried out based on a visual representation of the data. Visual comparison allows us to gain insight where plain computations of numerical differences alone cannot grasp the complex interdependencies in the data. Yet, visual comparison also comes at a cost. There are costs when interpreting the visual representation and costs when interactively carrying out the comparison.We present techniques to reduce some of the costs associated with visual comparison. We address cognitive costs for comparing objects that are spread across a visual representation and interaction costs for selecting and navigating between objects to be compared. Our techniques are illustrated by the example of comparing geographic regions in choropleth maps.
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    Analytic Behavior and Trust Building in Visual Analytics
    (The Eurographics Association, 2016) Sacha, Dominik; Boesecke, Ina; Fuchs, Johannes; Keim, Daniel A.; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Visual Analytics (VA) is a collaborative process between human and computer, where analysts are performing numerous interactions and reasoning activities. This paper presents our current progress in developing a note taking environment (NTE) that can be plugged to any VA system. The NTE supports the analysis process on the one hand, and captures user interactions on the other hand. Our aim is to integrate human lower- (exploration) with higher- (verification) level analytic processes and to investigate those together related to further human factors, such as trust building. We conducted a user study to collect and investigate analytic provenance data. Our early results reveal that analysis strategies and trust building are very individual. However, we were able to identify significant correlations between trust levels and interactions of particular participants.
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    IN2CO - A Visualization Framework for Intuitive Collaboration
    (The Eurographics Association, 2016) Rupprecht, Franca-Alexandra; Hamann, Bernd; Weidig, Christian; Aurich, Jan C.; Ebert, Achim; Enrico Bertini and Niklas Elmqvist and Thomas Wischgoll
    Today, the need for interaction and visualization techniques to fulfill user requirements for collaborative work is ever increasing. Current approaches do not suffice since they do not consider the simultaneous work of participating users, different views of the data being analyzed, or the exchange of information between different data emphases. We introduce Intuitive Collaboration (IN2CO), a scalable visualization framework that supports decision-making processes concerning multilevels and multi-roles. IN2CO improves the state of the art by integrating ubiquitous technologies and existing techniques to explore and manipulate data and dependencies collaboratively. A prototype has been tested by mechanical engineers with expertise in factory planning. Preliminary results imply that IN2CO supports communication and decision-making in a team-oriented manner.