DevLan/vispubs huggingface dataset:
Tangible remote controllers for wall-size displays
Authors: Yvonne Jansen, Pierre Dragicevic, Jean-Daniel Fekete
Published at CHI, 2012

We explore the use of customizable tangible remote controllers for interacting with wall-size displays. Such controllers are especially suited to visual exploration tasks where users need to move to see details of complex visualizations. In addition, we conducted a controlled user study suggesting that tangibles make it easier for users to focus on the visual display while they interact. We explain how to build such controllers using off-the-shelf touch tablets and describe a sample application that supports multiple dynamic queries.
The bohemian bookshelf: supporting serendipitous book discoveries through information visualization
Authors: Alice Thudt, Uta Hinrichs, Sheelagh Carpendale
Published at CHI, 2012

Serendipity, a trigger of exciting yet unexpected discoveries, is an important but comparatively neglected factor in information seeking, research, and ideation. We suggest that serendipity can be facilitated through visualization. To explore this, we introduce the Bohemian Bookshelf, which aims to support serendipitous discoveries in the context of digital book collections. The Bohemian Bookshelf consists of five interlinked visualizations each offering a unique overview of the collection. It aims at encouraging serendipity by (1) offering multiple visual access points to the collection, (2) highlighting adjacencies between books, (3) providing flexible visual pathways for exploring the collection, (4) enticing curiosity through abstract, metaphorical, and visually distinct representations of books, and (5) enabling a playful approach to information exploration. A deployment at a library revealed that visitors embraced this approach of utilizing visualization to support open-ended explorations and serendipitous discoveries. This encourages future explorations into promoting serendipity through information visualization.
The case of the missed icon: change blindness on mobile devices
Authors: Thomas Davies, Ashweeni Kumar Beeharee
Published at CHI, 2012

Insights into human visual attention have benefited many areas of computing, but perhaps most significantly visualisation and UI design [3]. With the proliferation of mobile devices capable of supporting significantly complex applications on small screens, demands on mobile UI design and the user's visual system are becoming greater. In this paper, we report results from an empirical study of human visual attention, specifically the Change Blindness phenomenon, on handheld mobile devices and its impact on mobile UI design. It is arguable that due to the small size of the screen - unlike a typical computer monitor - a greater visual coverage of the mobile device is possible, and that these phenomena may occur less frequently during the use of the device, or even that they may not occur at all. Our study shows otherwise. We tested for Change Blindness (CB) and Inattentional Blindness (IB) in a single-modal, mobile context and attempted to establish factors in the application interface design that induce and/or reduce their occurrences. The results show that both CB and IB can and do occur while using mobile devices. The results also suggest that the number of separate attendable items on-screen is directly proportional to rates of CB. Newly inserted objects were correctly identified more often than changes applied to existing on-screen objects. These results suggest that it is important for mobile UI designers to take these aspects of visual attention into account when designing mobile applications that attempt to deliver information through visual changes or notifications.
Trust me, i'm partially right: incremental visualization lets analysts explore large datasets faster
Authors: Danyel Fisher, Igor O. Popov, Steven Mark Drucker, m. c. schraefel
Published at CHI, 2012

Queries over large scale (petabyte) data bases often mean waiting overnight for a result to come back. Scale costs time. Such time also means that potential avenues of exploration are ignored because the costs are perceived to be too high to run or even propose them. With sampleAction we have explored whether interaction techniques to present query results running over only incremental samples can be presented as sufficiently trustworthy for analysts both to make closer to real time decisions about their queries and to be more exploratory in their questions of the data. Our work with three teams of analysts suggests that we can indeed accelerate and open up the query process with such incremental visualizations.
Understanding the verbal language and structure of end-user descriptions of data visualizations
Authors: Ronald A. Metoyer, Bongshin Lee, Nathalie Henry Riche, Mary Czerwinski
Published at CHI, 2012

Tools exist for people to create visualizations with their data; however, they are often designed for programmers or they restrict less technical people to pre-defined templates. This can make creating novel, custom visualizations difficult for the average person. For example, existing tools typically do not support syntax or interaction techniques that are natural to end users. To explore how to support a more natural production of data visualizations by end users, we conducted an exploratory study to illuminate the structure and content of the language employed by end users when describing data visualizations. We present our findings from the study and discuss their design implications for future visualization languages and toolkits.
V-model: a new innovative model to chronologically visualize narrative clinical texts
Authors: Heekyong Park, Jinwook Choi
Published at CHI, 2012

Visualizing narrative medical events into a timeline can have positive effects on clinical environments. However, the characteristics of natural language and medical environments make this representation more difficult. This paper explains the obstacles and suggests a solution called the V-Model. The V-Model is a new innovative time model that was developed to represent chronological narrative events in a medical domain. Forty medical students participated in evaluating this model. The experimental results show the new model successfully solved the modeling requirements and had better usability compared to conventional timeline models. All the participants assessed the new timeline as very useful in effectively understanding a patient's history.
Video summagator: an interface for video summarization and navigation
Authors: Cuong Nguyen 0003, Yuzhen Niu, Feng Liu 0015
Published at CHI, 2012

This paper presents Video Summagator (VS), a volume-based interface for video summarization and navigation. VS models a video as a space-time cube and visualizes the video cube using real-time volume rendering techniques. VS empowers a user to interactively manipulate the video cube. We show that VS can quickly summarize both the static and dynamic video content by visualizing the space-time information in 3D. We demonstrate that VS enables a user to quickly look into the video cube, understand the content, and navigate to the content of interest.
WebCrystal: understanding and reusing examples in web authoring
Authors: Kerry Shih-Ping Chang, Brad A. Myers
Published at CHI, 2012

Examples have been widely used in the area of web design to help web authors create web pages. However, without actually understanding how an example is constructed, people often have trouble extracting the elements they want and incorporating them into their own design. This paper introduces WebCrystal, a web development tool that helps users understand how a web page is built. WebCrystal contributes novel interaction techniques that let the user quickly access HTML and CSS information by selecting questions regarding how a selected element is designed. It provides answers using a textual description and a customized code snippet that can be copied-and-pasted to recreate the desired properties. WebCrystal also supports combining the styles and structures from multiple elements into the generated code snippet, and provides visualizations on the web page itself to explain layout relationships. Our user study shows that WebCrystal helped both novice and experienced developers complete more tasks successfully using significantly less time.
A Scale Space Based Persistence Measure for Critical Points in 2D Scalar fields
Authors: Jan Reininghaus, Natallia Kotava, David Günther, Jens Kasten, Hans Hagen, Ingrid Hotz
Published at Vis, 2011

This paper introduces a novel importance measure for critical points in 2D scalar fields. This measure is based on a combination of the deep structure of the scale space with the well-known concept of homological persistence. We enhance the noise robust persistence measure by implicitly taking the hill-, ridge- and outlier-like spatial extent of maxima and minima into account. This allows for the distinction between different types of extrema based on their persistence at multiple scales. Our importance measure can be computed efficiently in an out-of-core setting. To demonstrate the practical relevance of our method we apply it to a synthetic and a real-world data set and evaluate its performance and scalability.
About the Influence of Illumination Models on Image Comprehension in Direct Volume Rendering
Authors: Florian Lindemann, Timo Ropinski
Published at Vis, 2011

In this paper, we present a user study in which we have investigated the influence of seven state-of-the-art volumetric illumination models on the spatial perception of volume rendered images. Within the study, we have compared gradient-based shading with half angle slicing, directional occlusion shading, multidirectional occlusion shading, shadow volume propagation, spherical harmonic lighting as well as dynamic ambient occlusion. To evaluate these models, users had to solve three tasks relying on correct depth as well as size perception. Our motivation for these three tasks was to find relations between the used illumination model, user accuracy and the elapsed time. In an additional task, users had to subjectively judge the output of the tested models. After first reviewing the models and their features, we will introduce the individual tasks and discuss their results. We discovered statistically significant differences in the testing performance of the techniques. Based on these findings, we have analyzed the models and extracted those features which are possibly relevant for the improved spatial comprehension in a relational task. We believe that a combination of these distinctive features could pave the way for a novel illumination model, which would be optimized based on our findings.
Adaptive Extraction and Quantification of Geophysical Vortices
Authors: Sean Williams, Mark R. Petersen, Peer-Timo Bremer, Matthew Hecht, Valerio Pascucci, James P. Ahrens, Mario Hlawitschka, Bernd Hamann
Published at Vis, 2011

We consider the problem of extracting discrete two-dimensional vortices from a turbulent flow. In our approach we use a reference model describing the expected physics and geometry of an idealized vortex. The model allows us to derive a novel correlation between the size of the vortex and its strength, measured as the square of its strain minus the square of its vorticity. For vortex detection in real models we use the strength parameter to locate potential vortex cores, then measure the similarity of our ideal analytical vortex and the real vortex core for different strength thresholds. This approach provides a metric for how well a vortex core is modeled by an ideal vortex. Moreover, this provides insight into the problem of choosing the thresholds that identify a vortex. By selecting a target coefficient of determination (i.e., statistical confidence), we determine on a per-vortex basis what threshold of the strength parameter would be required to extract that vortex at the chosen confidence. We validate our approach on real data from a global ocean simulation and derive from it a map of expected vortex strengths over the global ocean.
An Efficient Direct Volume Rendering Approach for Dichromats
Authors: Weifeng Chen 0002, Wei Chen 0001, Hujun Bao
Published at Vis, 2011

Color vision deficiency (CVD) affects a high percentage of the population worldwide. When seeing a volume visualization result, persons with CVD may be incapable of discriminating the classification information expressed in the image if the color transfer function or the color blending used in the direct volume rendering is not appropriate. Conventional methods used to address this problem adopt advanced image recoloring techniques to enhance the rendering results frame-by-frame; unfortunately, problematic perceptual results may still be generated. This paper proposes an alternative solution that complements the image recoloring scheme by reconfiguring the components of the direct volume rendering (DVR) pipeline. Our approach optimizes the mapped colors of a transfer function to simulate CVD-friendly effect that is generated by applying the image recoloring to the results with the initial transfer function. The optimization process has a low computational complexity, and only needs to be performed once for a given transfer function. To achieve detail-preserving and perceptually natural semi-transparent effects, we introduce a new color composition mode that works in the color space of dichromats. Experimental results and a pilot study demonstrates that our approach can yield dichromats-friendly and consistent volume visualization in real-time.
An Interactive Local Flattening Operator to Support Digital Investigations on Artwork Surfaces
Authors: Nico Pietroni, Massimiliano Corsini, Paolo Cignoni, Roberto Scopigno
Published at Vis, 2011

Analyzing either high-frequency shape detail or any other 2D fields (scalar or vector) embedded over a 3D geometry is a complex task, since detaching the detail from the overall shape can be tricky. An alternative approach is to move to the 2D space, resolving shape reasoning to easier image processing techniques. In this paper we propose a novel framework for the analysis of 2D information distributed over 3D geometry, based on a locally smooth parametrization technique that allows us to treat local 3D data in terms of image content. The proposed approach has been implemented as a sketch-based system that allows to design with a few gestures a set of (possibly overlapping) parameterizations of rectangular portions of the surface. We demonstrate that, due to the locality of the parametrization, the distortion is under an acceptable threshold, while discontinuities can be avoided since the parametrized geometry is always homeomorphic to a disk. We show the effectiveness of the proposed technique to solve specific Cultural Heritage (CH) tasks: the analysis of chisel marks over the surface of a unfinished sculpture and the local comparison of multiple photographs mapped over the surface of an artwork. For this very difficult task, we believe that our framework and the corresponding tool are the first steps toward a computer-based shape reasoning system, able to support CH scholars with a medium they are more used to.
Artificial Defocus for Displaying Markers in Microscopy Z-Stacks
Authors: Alessandro Giusti, Pierluigi Taddei, Giorgio Corani, Luca Maria Gambardella, Cristina Magli, Luca Gianaroli
Published at Vis, 2011

As microscopes have a very shallow depth of field, Z-stacks (i.e. sets of images shot at different focal planes) are often acquired to fully capture a thick sample. Such stacks are viewed by users by navigating them through the mouse wheel. We propose a new technique of visualizing 3D point, line or area markers in such focus stacks, by displaying them with a depth-dependent defocus, simulating the microscope's optics; this leverages on the microscopists' ability to continuously twiddle focus, while implicitly performing a shape-from-focus reconstruction of the 3D structure of the sample. User studies confirm that the approach is effective, and can complement more traditional techniques such as color-based cues. We provide two implementations, one of which computes defocus in real time on the GPU, and examples of their application.
Asymmetric Tensor field Visualization for Surfaces
Authors: Darrel Palke, Zhongzang Lin, Guoning Chen, Harry Yeh, Paul Vincent, Robert S. Laramee, Eugene Zhang
Published at Vis, 2011

Asymmetric tensor field visualization can provide important insight into fluid flows and solid deformations. Existing techniques for asymmetric tensor fields focus on the analysis, and simply use evenly-spaced hyperstreamlines on surfaces following eigenvectors and dual-eigenvectors in the tensor field. In this paper, we describe a hybrid visualization technique in which hyperstreamlines and elliptical glyphs are used in real and complex domains, respectively. This enables a more faithful representation of flow behaviors inside complex domains. In addition, we encode tensor magnitude, an important quantity in tensor field analysis, using the density of hyperstreamlines and sizes of glyphs. This allows colors to be used to encode other important tensor quantities. To facilitate quick visual exploration of the data from different viewpoints and at different resolutions, we employ an efficient image-space approach in which hyperstreamlines and glyphs are generated quickly in the image plane. The combination of these techniques leads to an efficient tensor field visualization system for domain scientists. We demonstrate the effectiveness of our visualization technique through applications to complex simulated engine fluid flow and earthquake deformation data. Feedback from domain expert scientists, who are also co-authors, is provided.
Authalic Parameterization of General Surfaces Using Lie Advection
Authors: Guangyu Zou, Jiaxi Hu, Xianfeng Gu, Jing Hua 0001
Published at Vis, 2011

Parameterization of complex surfaces constitutes a major means of visualizing highly convoluted geometric structures as well as other properties associated with the surface. It also enables users with the ability to navigate, orient, and focus on regions of interest within a global view and overcome the occlusions to inner concavities. In this paper, we propose a novel area-preserving surface parameterization method which is rigorous in theory, moderate in computation, yet easily extendable to surfaces of non-disc and closed-boundary topologies. Starting from the distortion induced by an initial parameterization, an area restoring diffeomorphic flow is constructed as a Lie advection of differential 2-forms along the manifold, which yields equality of the area elements between the domain and the original surface at its final state. Existence and uniqueness of result are assured through an analytical derivation. Based upon a triangulated surface representation, we also present an efficient algorithm in line with discrete differential modeling. As an exemplar application, the utilization of this method for the effective visualization of brain cortical imaging modalities is presented. Compared with conformal methods, our method can reveal more subtle surface patterns in a quantitative manner. It, therefore, provides a competitive alternative to the existing parameterization techniques for better surface-based analysis in various scenarios.
Automatic Transfer Functions Based on Informational Divergence
Authors: Marc Ruiz, Anton Bardera, Imma Boada, Ivan Viola, Miquel Feixas, Mateu Sbert
Published at Vis, 2011

In this paper we present a framework to define transfer functions from a target distribution provided by the user. A target distribution can reflect the data importance, or highly relevant data value interval, or spatial segmentation. Our approach is based on a communication channel between a set of viewpoints and a set of bins of a volume data set, and it supports 1D as well as 2D transfer functions including the gradient information. The transfer functions are obtained by minimizing the informational divergence or Kullback-Leibler distance between the visibility distribution captured by the viewpoints and a target distribution selected by the user. The use of the derivative of the informational divergence allows for a fast optimization process. Different target distributions for 1D and 2D transfer functions are analyzed together with importance-driven and view-based techniques.
Branching and Circular Features in High Dimensional Data
Authors: Bei Wang 0001, Brian Summa, Valerio Pascucci, Mikael Vejdemo-Johansson
Published at Vis, 2011

Large observations and simulations in scientific research give rise to high-dimensional data sets that present many challenges and opportunities in data analysis and visualization. Researchers in application domains such as engineering, computational biology, climate study, imaging and motion capture are faced with the problem of how to discover compact representations of highdimensional data while preserving their intrinsic structure. In many applications, the original data is projected onto low-dimensional space via dimensionality reduction techniques prior to modeling. One problem with this approach is that the projection step in the process can fail to preserve structure in the data that is only apparent in high dimensions. Conversely, such techniques may create structural illusions in the projection, implying structure not present in the original high-dimensional data. Our solution is to utilize topological techniques to recover important structures in high-dimensional data that contains non-trivial topology. Specifically, we are interested in high-dimensional branching structures. We construct local circle-valued coordinate functions to represent such features. Subsequently, we perform dimensionality reduction on the data while ensuring such structures are visually preserved. Additionally, we study the effects of global circular structures on visualizations. Our results reveal never-before-seen structures on real-world data sets from a variety of applications.
Context Preserving Maps of Tubular Structures
Authors: Joseph Marino, Wei Zeng 0002, Xianfeng Gu, Arie E. Kaufman
Published at Vis, 2011

When visualizing tubular 3D structures, external representations are often used for guidance and display, and such views in 2D can often contain occlusions. Virtual dissection methods have been proposed where the entire 3D structure can be mapped to the 2D plane, though these will lose context by straightening curved sections. We present a new method of creating maps of 3D tubular structures that yield a succinct view while preserving the overall geometric structure. Given a dominant view plane for the structure, its curve skeleton is first projected to a 2D skeleton. This 2D skeleton is adjusted to account for distortions in length, modified to remove intersections, and optimized to preserve the shape of the original 3D skeleton. Based on this shaped 2D skeleton, a boundary for the map of the object is obtained based on a slicing path through the structure and the radius around the skeleton. The sliced structure is conformally mapped to a rectangle and then deformed via harmonic mapping to match the boundary placement. This flattened map preserves the general geometric context of a 3D object in a 2D display, and rendering of this flattened map can be accomplished using volumetric ray casting. We have evaluated our method on real datasets of human colon models.