Visualization Blog

Ideas, Papers and Thoughts on the field of Visualization

Posts Tagged ‘information visualization

Visweek 2011 – Perception and Cognition for Visualization, Visual Data Analysis & Computer Graphics

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I had mentioned in an earlier post that this tutorial promises to be an amazing one and so it was. Here is an outline of the workshop.

Bernice E. Rogowitz covered fundamentals in human perception and cognition, and discussed how they apply to visualization. She covered a huge array of topics, ranging from the pupil being partially responsible for our depth perception, all the way to color theory and how it relates directly to the biology of the human eye.

The presentation had a great flow, starting at a very high level to give everyone an idea of what questions they would be able to answer at the end. As the talk progressed, she covered detailed biological details of the human eye, and progressed to the intersection of perceptual issues and computer science.

In the biological portion, we learned that there are five layers of cells in the retina, each responsible for different tasks. Much of the interesting stuff happens at the very beginning (photoreceptor distribution) and then further into the process at the ganglion cells. She went over how lateral inhibition is caused by the spatial distribution of the photoreceptors connected to a single ganglion cell, and how this is the reason for several of the optical illusions we perceive. She did a great job of explaining the connections between biology and perceptual issues.

Cultural differences were also addressed. The eye movements we have are actually learned when we learn how to read. Cultures with different reading directions have substantially different reading directions.

The section on the Striate Cortex was especially interesting. This is the first time in the visual system that images from each eye are merged (the point where depth perception occurs). This section sends output to 60% of the brain! This is a huge amount, and makes the visual system incredibly important to the decision making process.

This tutorial had a huge quantity of useful information and was really well put together! She concluded with a great summary of four things to remember:

  1. There are different response rates for different stimuli, how well do you want to convey magnitude information?
  2. Color and luminance mechanisms have different spatial sensitivities.
  3. Certain visual information is perceived “pre-attentively” such as color.
  4. How the world is perceived depends on what the user is trying to accomplish.
These notes were transcribed by Lane Harrison (@laneharrison) and Drew Skau(@seeingstructure). They are both graduate students at UNCC. Thanks guys!! This is almost as good as being there.

Interactive visualization at your fingertips

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With today’s release of Tableau Public, Tableau Software has opened up infinite possibilites for researchers, corporations and enthusiasts alike to interact, explore and play with their data. More importantly, with Tableau Public one can now have ‘interactive’ visualizations online as opposed to static images. This is a step in the right direction for Data Visualization software, since increasingly one hears from domain experts who want to ‘use’ software and not have to write programs (however small or easy those programs may seem to the developer of the software). Tableau now allows researchers to explore their data and collaborate more effectively instead of having to share static ‘screenshots’ via email.

Such uses of visualization software have already been explored and shown to be hugely successful by the ManyEyes team in their CHI ’08 paper, but the capabilities and strengths of both the products are in somewhat disjoint areas. For example, Tableau focuses on the Business Intelligence community and lacks certain visualizations such as Treemaps or Text visualizations (which ManyEyes seem to do really well). Other interesting and inspiring uses of Tableau Public can be found in their Gallery at Dont forget to check out the NYC Graffiti workbook that they have online. Detailed training videos can be found at

ManyEyes – Reader s of this blog already know my fondness for IBM’s Many Eyes. ManyEyes has been a pioneer in this field of online visualization software that facilitates data visualization without the need for programming. Research papers from the Many Eyes team detailing user interactions and unexpected uses of the visualization software can be found at

Verifiable is another such website that allows online visualization of data. So far the data visualizations that are possible are limited to bar charts, scatter plots and line charts but the trend is definitely promising and I hope they continue to improve the excellent service. A video can be found online at

Swivel is similar to Verifiable, where one can upload data and create online interactive visualizations. Videos for all the features in Swivel can be found at Unfortunately, they have a 15-day free trial that restricts the widespread use of their tools.

As I interact with experts and students from domains as wide as political sciences, biology, economics and so on, I am pleased to hear the awareness that they have for effective visualization but I am sometimes disheartened to have to tell them to learn programming to learn some of our nifty tools. Tableau Public, IBM Many Eyes and others are exceptional in the service that they provide. I envision more research groups, corporate websites and so on posting interactive visualizations with a ‘Powered by Tableau’ icon or something similar in the bottom right corner.

Ten most cited TVCG papers

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The IEEE Transactions on Visualization and Computer Graphics journal completed 15 years this month and in the editorial,  the 10 most cited papers in the last 15 years have been mentioned. Some of them are survey papers and some are classics. These papers have received between 550-250 citations in the past 15 years.

Here are the papers (in no particular order):

  1. I. Herman, G. Melançon, and M.S. Marshall, “Graph Visualization and Navigation in Information Visualization: A Survey,” IEEE Trans. Visualization and Computer Graphics, vol. 6, no. 1, pp. 24-43,Jan.-Mar. 2000.graphvis
  2. M. Alexa, J. Behr, D. Cohen-Or, S. Fleishman, D. Levin and C.T. Silva, “Computing and Rendering Point Set Surfaces,” IEEE Trans. Visualization and Computer Graphics, vol. 9, no. 1, pp. 3-15,Jan.-Mar. 2003.alexa
  3. J.T. Klosowski, M. Held, J.S.B. Mitchell, H. Sowizral and K. Zikan, “Efficient Collision Detection Using Bounding Volume Hierarchies of k-DOPs,” IEEE Trans. Visualization and Computer Graphics, vol. 4, no. 1, pp. 21-36,Jan.-Mar. 1998.collision1
  4. J. Rossignac, “Edgebreaker: Connectivity Compression for Triangle Meshes,” IEEE Trans. Visualization and Computer Graphics, vol. 5, no. 1, pp. 47-61,Jan.-Mar. 1999. GVU Tech Report.edgebreaker
  5. D.A. Keim, “Information Visualization and Visual Data Mining,” IEEE Trans. Visualization and Computer Graphics, vol. 7, no. 1, pp. 1-8,Jan.-Mar. 2002.keim
  6. N. Max, “Optical Models for Direct Volume Rendering,” IEEE Trans. Visualization and Computer Graphics, vol. 1, no. 2, pp. 99-108,June 1995.max
  7. P.M. Hubbard, “Collision Detection for Interactive Graphics Applications,” IEEE Trans. Visualization and Computer Graphics, vol. 1, no. 3, pp. 218-230,Sept. 1995.collision2
  8. S. Lee, G. Wolberg, and S.Y. Shin, “Scattered Data Interpolation with Multilevel B-Splines,” IEEE Trans. Visualization and Computer Graphics, vol. 3, no. 3, pp. 228-244,July-Sept. 1997.scattered
  9. G.W. Larson, H. Rushmeier, and C. Piatko, “A Visibility Matching Tone Reproduction Operator for High Dynamic Range Scenes,” IEEE Trans. Visualization and Computer Graphics, vol. 3, no. 4, pp. 291-306,Oct.-Dec. 1997.tone
  10. K. Perlin, “Real Time Responsive Animation with Personality,” IEEE Trans. Visualization and Computer Graphics, vol. 1, no. 1, pp. 5-15,Mar. 1995.perlin

Please feel free to add any other TVCG papers that have influenced your work significantly. Congrats TVCG and all the people involved with it!

Visualization in Sports

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This article is not about “improving your ability in sports using visualization“. This post is focused on the ubiquity of computer graphics and visualization in sports. As a television viewer, player, coach or just a curious  individual, you may have seen some of these visualizations for analyzing a game. It seems more common for coaches to use visual analytic tools to analyze the opposing teams in almost all sports now. 

Visualizing American football (NFL)

  • Professor Chris Healey from NCSU has an interesting project on visualizing NFL games. The project details can be found at is a screenshot of a small section of the visualization of the entire SuperBowl 2009 game between Arizona and Pittsburgh. 




Visualizing Baseball (MLB


Visualizing Basketball (NBA  & WNBA)


Visualizing Cricket 

  • -Infographics is widely used in telecasts – Bowling overview, batting overview (wagon wheel) to show which parts of a ground is a particular player hitting to in that innning. A snapshot of a wagon wheel (as it is called) is shown here (Image credits: cricinfo) 




Golf swing visualization

  • Urtasun et al. published a paper for 3D tracing of the golf swing. Here is the citation and the link to the paper: Raquel Urtasun , David J. Fleet , Pascal Fua, Monocular 3-D Tracking of the Golf Swing , Proceedings of the 2005 IEEE Computer Society Conference on Computer Vision and Pattern Recognition (CVPR’05) – Volume 2, p.932-938, June 20-26, 2005.  Here is a snapshot from their paper. golf
  • Naturally, there would be a company selling a product for such sort of a thing. Flightscope, the company that tracks a tennis ball for debatable calls during a match,  uses 3D Doppler tracking for tracking your golf swing

I am sure you have seen visualization and infographics being widely used in your favorite sports. Please feel free to add a link or even mention it in the comments section.

Visualization in politics

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As the November elections approach, I’ve been observing more and more websites, newspapers and even a few researchers conveying data and trends using visualization techniques. is a website which claims to correctly project election results and one that is getting a lot of media coverage [and on the Colbert report] has a few examples of visualizations. is a wonderful website that tracks the number of news articles that are focused on one of the presidential candidates. Here is an example visualization from their main page. It reminded me of Tufte’s Sparklines, which convey information so succinctly. 

Screenshot from the website

Screenshot from the website

But, New York Times scores a home-run again by making an interactive election visualization that allows readers to explore their data, create your own prediction map and much much more. It even allows you pick different ‘opinion polls’ and see what they’re predicting. Here’s a snapshot from the ‘Wall Street Journal/NBC News’ predictions. It can be found at

NYTimes Interactive Election Visualization

NYTimes Interactive Election Visualization has its own version of visualizations for polling and electoral map calculator

Microsoft’s Live Labs too has developed “Political Streams” which is basically an integrated visualization tool of sorts, that allows one to visualize the attention an event is getting. They divide the ‘attention’ into ‘news’ attention and ‘blog’ attention. It would be more interesting if they would allow users to start their own streams. 

Well, I’m happy to see that there has been some significant interest in the academic community as well. 

Geoff Draper from the University of Utah will be presenting a paper in the IEEE Information Visualization 2008 conference (which is part of IEEE VisWeek 2008) titled: “Who Votes For What? A Visual Query Language for Opinion Data” by Geoffrey M. Draper & Richard F. Riesenfeld. 

Visualization researchers such as Chris Healey from NCSU and Jean Daniel Fekete from INRIA have worked on visualizing election results in the past.  

Chris Healey’s 2004 US Presidential Election research:

Jean Daniel Fekete’s 2004 French Election related work:


As always, my favorite visualization website, Many Eyes, is full of users trying to visualize everything from 

Palin’s Comments During the VP Debate 

Obama’s Nomination Acceptance Speech at the DNC

Obama DNC Acceptance Speech Visualization

Obama DNC Acceptance Speech Visualization

Many more such elections related visualization have been created and can be browsed at

I feel that even though some visualizations provide interactivity, most of them seem to stay away from using some of the wonderful information visualization research that has been going on to allow users to obtain insight such as the  ‘Visual Information Exploration for the Web‘ by Sheelagh Carpendale. I’m sure you have seen some good and bad visualizations this election season. Please feel free to post links or mention them in the comments.

Written by alark

October 10, 2008 at 4:27 pm

IEEE Visualization 2008 (Vis, InfoVis, VAST) papers posted

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The IEEE Visualization 2008 conference will be held in Columbus, Ohio this year. The VGTC committee decided to call the paper presentations, art exhibits, panels, posters, worshops:VisWeek . The idea is to have all the events that are based on data visualization of some sort are clubbed under one event name. Previously, in the past people would attend InfoVis and then leave or attend only Vis (which generally starts on a tuesday/wednesday) and then leave at the end of the week. I think its a great idea that they are allowing attendees to attend the whole week of amazing talks and presentations. I am sure such an endeavor will encourage interactions between people and lead to more interesting results for the community.

Well, as one of the marquee events of the conference, the list of accepted papers for the conference has been posted on their website.

Vis papers

InfoVis papers

VAST papers

I am keenly looking forward to reading some papers and shall post my thoughts on them as soon as I can my hands on them 🙂

The posters, panels, workshops, tutorials etc links too have been updated. All the links can be found from the main page at

It definitely promises to be a great event. If you have a preprint of an accepted paper that you wouldnt mind linking to, please do so in the comments section.

Which papers are you looking forward to?  Do write and let me know. 

The preprints of the accepted papers that are online can be found at

Written by alark

August 29, 2008 at 4:07 pm