Tag Archives: Visualization

RIVIC Graduate School 2014

Tim Weyrich talk at RIVIC graduate school 2014, Swansea

Tim Weyrich talk at RIVIC graduate school 2014, Swansea

The fifth annual RIVIC Graduate School was held 16th-17th June 2014 in Swansea, setting a new record of 37 talks by students and researchers, with 3 keynote talks from Majid Mirmehdi (Bristol), Tim Weyrich (UCL) and Kurt Debattista (Warwick). The event was arranged over two days in sunny Swansea with a wide range of talks in the topics of Vision, Graphics and Visualisation (Visual Computing). Our conference dinner was held in the Grape and Olive, the 27th floor of the Meridian tower offering superb views over Swansea bay, the city and local countryside.

The RIVIC Graduate School is an excellent opportunity for researchers across the RIVIC sites (Swansea, Aberystwyth, Bangor and Cardiff) to meet up, discuss research projects, seek ideas and solutions, collaborate and generally see the active and varied Visual Computing research ongoing across Wales. We also have keynote talks from excellent researchers, including this year from Majid Mirmehdi (Bristol), Tim Weyrich (UCL) and Kurt Debattista (Warwick).

Majid Mirmehdi (Bristol) spoke about the SPHERE project. In particular he gave a case study of using low cost consumer devices such as Kinect to measure progression of rehabilitation. The ultimate aim is to instrument houses with several sensors and video systems to monitor the health of occupants. He also gave some real-time automotive applications such as road sign detection and in car human/car interaction detection.

Tim Weyrich’s (UCL) talk “Bespoke Computer Graphics Systems for Cultural Heritage Applications” demonstrated how off-the-shelf devices can be re-engineered and integrated with novel software and algorithms to provide robust solutions to real-world heritage problems such as matching up smashed mosaic tiles to aid reconstruction and restoration work.

Kurt Debattista’s (Warwick) talk “High-Fidelity Graphics” covered the past, current and future challenges for high quality global illumination rendering in terms of usability, computational load and adoption. Kurt contextualised his work with industrial experience in application areas of car model rendering (with Land Rover) and architectural applications (with Arup).

About EuroVis 2014 at Swansea University

Eurovis 2014EuroVis 2014, hosted by Swansea University in the UK, was the
16th annual visualization gathering organized by the EuroGraphics Working
Group on Data Visualization and supported by the Visualization and Graphics
Technical Committee (VGTC). EuroVis has been a EuroGraphics and VGTC
co-supported international visualization symposium held in Europe annually
since 1999. In 2012 EuroVis graduated to a conference. The conference
attracted 258 delegate from 25 countries throughout the world.

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Graph Drawings: as created by users (or ‘Doing the Future Work’), Helen Purchase, Glasgow

Here’s an upcoming seminar at 2pm in Robert Recorde room, Thursday May 1st.

Much effort has been spent on designing algorithms for the automatic layout of graphs. Typically, the worth of these algorithms has been determined by their computational efficiency and by the extent to which the graph drawings they produce conform to pre-defined “aesthetics” (for example, minimising the number of edge crosses and edge bends, or maximising symmetry).

Prior experimental work has focussed on the extent to which the layout of a graph drawing assists with the comprehension of the embodied relational information. This seminar presents an alternate approach to determining the relative worth of graph layout aesthetics, based on how users create their own graph drawings. The seminar will present the results of both the published research experiments, as well as two follow-up studies.

Dr Helen Purchase is Senior Lecturer in the School of Computing Science at the University of Glasgow. She has worked in the area of empirical studies of graph layout for several years, and also has research interests in visual aesthetics, task-based empirical design, collaborative learning in higher education, and sketch tools for design. She has recently written a book on Empirical methods for HCI research.

Helen Purchase Seminar SlidesA healthy critical attitude: Revisiting the results of a graph drawing study, Journal of Graph Algorithms and Applications, vol. 18, no. 2, pp. 281-311 (2014) DOI: 10.7155/jgaa.00323

Transformation of an Uncertain Video Search Pipeline to a Sketch-based Visual Analytics Loop

Video search interface

Video search interface

Traditional sketch-based image or video search systems rely on machine learning concepts as their core technology. However, in many applications, machine learning alone is impractical since videos may not be semantically annotated sufficiently, there may be a lack of suitable training data, and the search requirements of the user may frequently change for different tasks. In this work, we develop a visual analytics systems that overcomes the shortcomings of the traditional approach. We make use of a sketch-based interface to enable users to specify search requirement in a flexible manner without depending on semantic annotation. We employ active machine learning to train different analytical models for different types of search requirements. We use visualization to facilitate knowledge discovery at the different stages of visual analytics. This includes visualizing the parameter space of the trained model, visualizing the search space to support interactive browsing, visualizing candidature search results to support rapid interaction for active learning while minimizing watching videos, and visualizing aggregated information of the search results. We demonstrate the system for searching spatio-temporal attributes from sports video to identify key instances of the team and player performance.

pdficon_largePowerpoint iconPhil A. Legg, David H. S. Chung, Matt L. Parry, Rhodri Bown, Mark W. Jones, Iwan W. Griffiths, Min Chen.
IEEE Transactions on Visualization and Computer Graphics, 19(12), 2109-2118.

James Walker passes MRes

Today, James Walker successfully defended his MRes Thesis:
Visualization of Large, High-Dimensional, Time-Dependent, Abstract Data.

Well done James and Bob (supervisor). The internal examiner was Ben Mora and the external was Yulia Hicks (Cardiff).

An Empirical Study on Using Visual Embellishments in Visualization

In written and spoken communications, figures of speech (e.g., metaphors and synecdoche) are often used as an aid to help convey abstract or less tangible concepts. However, the benefits of using rhetorical illustrations or embellishments in visualization have so far been inconclusive. In this work, we report an empirical study to evaluate hypotheses that visual embellishments may aid memorization, visual search and concept comprehension. One major departure from related experiments in the literature is that we make use of a dualtask methodology in our experiment. This design offers an abstraction of typical situations where viewers do not have their full attention focused on visualization (e.g., in meetings and lectures). The secondary task introduces “divided attention”, and makes the effects of visual embellishments more observable. In addition, it also serves as additional masking in memory-based trials. The results of this study show that visual embellishments can help participants better remember the information depicted in visualization. On the other hand, visual embellishments can have a negative impact on the speed of visual search. The results show a complex pattern as to the benefits of visual embellishments in helping participants grasp key concepts from visualization.

Rita Borgo, Alfie Abdul-Rahman, Farhan Mohamed, Philip W. Grant, Irene Reppa, Luciano Floridi, and Min Chen

MatchPad: Interactive Glyph-Based Visualization for Real-Time Sports Performance Analysis

Today real-time sports performance analysis is a crucial aspect of matches in many major sports. For example, in soccer and rugby, team analysts may annotate videos during the matches by tagging specific actions and events, which typically result in some summary statistics and a large spreadsheet of recorded actions and events. To a coach, the summary statistics (e.g., the percentage of ball possession) lacks sufficient details, while reading the spreadsheet is time-consuming and making decisions based on the spreadsheet in real-time is thereby impossible. In this paper, we present a visualization solution to the current problem in real-time sports performance analysis. We adopt a glyph-based visual design to enable coaching staff and analysts to visualize actions and events “at a glance”. We discuss the relative merits of metaphoric glyphs in comparison with other types of glyph designs in this particular application. We describe an algorithm for managing the glyph layout at different spatial scales in interactive visualization. We demonstrate the use of this technical approach through its application in rugby, for which we delivered the visualization software, MatchPad, on a tablet computer. The MatchPad was used by the Welsh Rugby Union during the Rugby World Cup 2011. It successfully helped coaching staff and team analysts to examine actions and events in detail whilst maintaining a clear overview of the match, and assisted in their decision making during the matches. It also allows coaches to convey crucial information back to the players in a visually-engaging manner to help improve their performance.

Phil A. Legg, David H. S. Chung, Matthew L. Parry, Mark W. Jones, Rhys Long, Iwan W. Griffiths and Min Chen.
Eurovis 2012, Computer Graphics Forum 31(3), 1255-1264, 2012. [doi] [BibTeX]

Visualization of Large, Time-Dependent, Abstract Data with Integrated Spherical and Parallel Coordinates

Parallel Coordinates with Spherical axisParallel coordinates is one of the most popular and widely used visualization techniques for large, high dimensional data. Often, data attributes are visualized on individual axes with polylines joining them. However, some data attributes are more naturally represented with a spherical coordinate system. We present a novel coupling of parallel coordinates with spherical coordinates, enabling the visualization of vector and multi-dimensional data. The spherical plot is integrated as if it is an axis in the parallel coordinate visualization. This hybrid visualization benefits from enhanced visual perception, representing vector data in a more natural spatial domain and also reducing the number of parallel axis within the parallel coordinates plot. This raises several challenges which we discuss and provide solutions to, such as, visual clutter caused by over plotting and the computational complexity of visualizing large abstract, time-dependent data. We demonstrate the results of our work-in-progress visualization technique using biological animal tracking data of a large, multi-dimensional, time-dependent nature, consisting of tri-axial accelerometry samples as well as several additional attributes. In order to understand marine wildlife behavior, the acceleration vector is reconstructed in spherical coordinates and visualized alongside with the other data attributes to enable exploration, analysis and presentation of marine wildlife behavior.

James Walker, Zhao Geng, Mark W. Jones, Robert S. Laramee.
Eurovis Short Papers, 43-47, 2012. [doi] [BibTex]

Temporal Visualization of Boundary-based Geo-information Using Radial Projection

This work is concerned with a design study by an interdisciplinary team on visualizing a 10-year record of seasonal and inter-annual changes in frontal position (advance/retreat) of nearly 200 marine terminating glaciers in Greenland. Whilst the spatiotemporal nature of the raw data presents a challenge to develop a compact and intuitive visual design, the focus on coastal boundaries provides an opportunity for dimensional reduction. In this paper, we report the user-centered design process carried out by the team, and present several visual encoding schemes that have met the requirements including compactness, intuitiveness, and ability to depict temporal changes and spatial relations. In particular, we designed a family of radial visualization, where radial lines correspond to different coastal locations, and nested rings represent the evolution of the temporal dimension from inner to outer circles. We developed an algorithm for mapping glacier terminus positions from Cartesian coordinates to angular coordinates. Instead of a naive uniform mapping, the algorithm maintains consistent spatial perception of the visually-sensitive geographical references between their Cartesian and angular coordinates, and distributes other termini positions between primary locations based on coastal distance. This work has provided a useful solution to address the problem of inaccuracy in change evaluation based on pixel-based visualization [BPC10].

Y. Drocourt, R. Borgo, K. Scharrer, T. Murray, S.I. Bevan, M. Chen.
Computer Graphics Forum Intl. Journal, volume 30, number 3, year 2011, pp. 981-990, presented also at EuroVis Conference 2011, May 31-June 3, Bergen, Norway.