Tag Archives: visualisation

You have beautiful ize. [Weekly Head Voices #62]

Posted on November 19, 2011 by cpbotha| 1 Comment

I completely lack the genes that usually cause human males to have a thing for cars, but I do love Top Gear. This trailer for a fictional 60s detective show, made by Jeremy Clarkson, James May and Richard Hammond, encapsulates many of the reasons why:

Moustaches, guns, girls, cars and Hammond karate-chopping the porter at Playboy Club London for absolutely no reason whatsoever at 41 seconds can be nothing but 100% pure AWESOME.

It’s crazily busy at the moment, for a large part due to the extra load of having to teach and revamp, AT THE SAME TIME, the TU Delft’s postgraduate Data Visualization course. I’ve chucked out the written exam and the structured lab work, and exchanged it for paper reading, class discussion and four independent projects, inspired by positive experience with my Medical Visualization Ninja Training Course (third year in the running, Ninjas all over the place!), the postgraduate InfoVis course I gave at Stellenbosch and of course the teaching materials of esteemed colleagues at UBC, Harvard, Berkeley and Stanford. With a bit of luck, we will soon deliver a whole class of new-style DataVis Ninjas.

At a recent conference, I ran into an erudite half-British colleague from the far North, who in a few minutes almost managed to turn my world into rubble. You see, I’ve always proudly promoted the use of the -ise forms of certain words, such as visualise, realise, colonise and so forth, these being examples of British English. (Obviously, I adapt when American English is required.)

It turns out that, as is the case with life in general, it’s unfortunately not as simple as that.

It turns out that many of the -ise words are originally from the Greek or the Latin with “-ize” endings, and therefore the Oxford spelling prefers their use, although it accepts the “-ise” forms as well. On the other hand, the Cambridge University Press, as well as the mainstream media and most of the public in Britain and the former colonies, has a strong preference for the “-ise” forms. Certain other words like for example advertise, advise and surprise always take the “-ise” form in British English.

So now I’m faced with this conundrum. It would otherwise not have been such an issue, but the words “visualise” and “visualisation” come up quite often during my work day. Sticking to “-ise” is easier and still correct when in British English mode, but “-ize” for those few words of Greek  and Latin origin could perhaps be considered more correct, and has the great advantage of allowing me to standardise on “visualize” as the canonical form of that important term. However, then I would run the risk of confusing the “-ize” and the true “-ise” words in Oxford English, potentially leading to painful embarrassment at the many cocktail parties that I frequent.

So you see, the Universe is just full of mysteries. Another mystery that has plagued humankind for decades, is what would happen if Stephen Hawking and Albert Einstein got involved in a rap battle. Well humankind, wonder no more:

Ok kids, thank you for tuning in again. Have a great week, I hope to see you again soon!

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EuroVis 2011

Posted on June 26, 2011 by cpbotha| 1 Comment

I’ve written before about EuroVis, the most important European scientific conference on visualisation. In 2009, it took place in Berlin, in 2010 it was in Bordeaux, and, an a surprise non-twist of alliteration, the 2011 edition was held in Bergen, Norway. With 216 attendees and a practically perfect organization, this year’s edition has been described as the biggest and the best EuroVis ever. In a bid to save some time (I still owe you a mega-edition of the Weekly (actually Monthly) Head Voices), I’m going to give my biased account in bullet-list form:

  • On Tuesday evening, we were welcomed by the very charismatic vice mayor of Bergen in the Tårnsalen of the Lysverket building of the Bergen Art Museum. It seems the photo I took of the inside of the art deco tower, built in 1938, is quite a popular shot. The food was divine, thank you very much.

Art Deco tower from the inside in the Tårnsalen, Lysverket.

  • The next morning, during the conference opening, the following Bergen (rainiest city in Europe) joke was told: A visitor asks a local boy in exasperation “Does it rain like this all the time?” and the little boy answers “I don’t know, I’m only 12 years old!”.
  • The conference keynote was given by Scott McCloud, American cartoonist and comic theorist, on aspects of visual communication. This was most probably the best presentation I’ve ever had the privilege of experiencing. Besides brilliant oratorship, his slides are somehow more a visual stream of consciousness affair than discrete quanta of information. When I grow up, I’m going to present like that.

As per usual, I get to award the Weekly Head Voices Best Paper awards, and they go to the following papers:

  • A Shader Framework for Rapid Prototyping of GPU-Based Volume Rendering by Christian Rieder, Stephan Palmer, Florian Link and Horst K. Hahn. Rieder and his colleagues have constructed a full GPU-based volume rendering pipeline in MeVisLab of which the various shader based components are modifiable at runtime. This means that you can prototype your GPU-based volume rendering ideas in no time flat!
  • Curve Density Estimates by Ove Daae Lampe and Helwig Hauser. Back to basics and really important work on the effective visualisation of complex curves at any resolution, with smooth scaling between levels.
  • A Gradient-Based Comparison Measure for Visual Analysis of Multifield Data by Suthambhara Nagaraj, Vijay Natarajan and Ravi S. Nanjundiah. Another back-to-basics paper in which the authors show how to find the agreement between hundreds of scalar fields and visualise this agreement, thus enabling comparison.

The slightly less prestigious EuroVis 2011 Best Paper awards went to:

  1. Uncertainty-Aware Exploration of Continuous Parameter Spaces Using Multivariate Prediction  by Wolfgang Berger, Harald Piringer, Peter Filzmoser, Eduard Gröller. I was unfortunately in the other session, but was told by numerous colleagues that this was indeed an award-winning presentation as well.
  2. A User Study of Visualization Effectiveness Using EEG and Cognitive Load by Erik Anderson, Kristin Potter, Laura Matzen, Jason Shepherd, Gilbert Preston, Claudio Silva. This was presented in the Evaluation session which I had the privilege of chairing. It is indeed a very compelling idea to measure the effectiveness of a visualisation through cognitive load and this paper documents the first very important steps in this direction.
  3. A Gradient-Based Comparison Measure for Visual Analysis of Multifield Data by Suthambhara Nagaraj, Vijay Natarajan and Ravi S. Nanjundiah. This was also amongst the more prestigious WHV best paper award winners, see above!

The rest of the conference featured the following bullets:

  • During the social event on Thursday evening, Frits Post (my boss), was elevated to the rank of Eurographics Honorary Fellow, recognizing his service to and standing in the visualisation community. Including this newest addition, there are only five (5!) EG Honorary Fellows in the world today. I am very proud!
  • During the first session of the morning after the social event, I had the exquisite privilege of presenting the work of my Brazilian colleagues: Piecewise Laplacian-based Projection for Interactive Data Exploration and Organization by Fernando V. Paulovich, Danilo M. Eler, Jorge Poco, Charl P. Botha, Rosane Minghim, Luis G. Nonato. I really do like presenting at events like these, and it’s been a while. Do read and cite the paper, it documents a practical way of reducing any set of high-dimensional data points to the visual space, and enabling interaction with those points on the visual space!
  • The capstone of the conference was presented by the legendary Prof. E. Gröller, also known by the whole community as Meister. In typical style, the title of his talk was only announced during the talk itself. The title was The Haunted Swamps of Heuristics. In this philosophical and visionary contribution, it was argued that algorithms and parameters are too deeply intertwined to focus only on the former, but that it was more important to study, in detail, the exact behaviour of the latter. More broadly speaking, we need to accept the fact that there is a great deal of uncertainty also in the parameter spaces of our algorithms, but that this uncertainty can and should be dealt with correctly.

That thought-provoking capstone and this blog post will share the same concluding quote:

Doubt is not a pleasant condition, but certainty is absurd. — Voltaire / Gröller

I hope to see you in the comments below! You could also opt to click on my shiny new +1 button, or my slightly older but no less shiny retweet or facebook share buttons.

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An Inside Job. [Weekly Head Voices #33]

Posted on November 21, 2010 by cpbotha| 6 Comments

Hiatus: temporarily over.

My sleeping patterns are not quite what they used to be, mostly due to the latest manifestation of our little gene pool over here. Added to that, I’ve been really busy. Added to that, work has been throwing unnecessary curve-balls that have done their part in keeping me (pre)-occupied. In the end, a dash of perspective, several extremely wise friends and a generally sunny predisposition go a really long way, so here I am. :)

In this post, I’m going to touch upon the highlights of the past seven weeks (40 to 46) and I’m going to do so with bullets, seeing as I’m in a bullety-kind of mood.

  • I spent a week in Stellenbosch teaching Information Visualisation! Read all about it in this special blog post.
  • The week after that my mom came to visit us. She really has the best genes.
  • I met my new work laptop: A Dell Latitude E6410 with Core i5 M540 2.53GHz CPU, 4G ram, 500G HDD, NVidia NVS 3100m GPU with 512 MB video mem. It’s a 14″ latop (15.4″ is a completely useless format, flame me in the comments), but due to the materials used quite heavy. I like it!
  • Another one of our STW NIG research proposals has been granted. I conceived and developed this one together with colleagues from the LUMC Departments of Anatomy, of Surgery and of Orthopaedics. The title is High-definition Atlas-based surgical planning for Pelvic Surgery and we get to combine high-resolution human histology, mega-volume rendering, , biomechanical modelling and surgical simulation. With this grant we can appoint two more Ph.D. students (one in my group, one at the LUMC) for four years to work on this!!
  • The week after that I went to Salt Lake City (Utah, US and A) to attend the conference previously known as IEEE Visualization. It was AWESOME! (blog post half-written, will soon publish).
  • The week after that I had a really cool dream: I was playing high-speed catch with a bunch of people outside. The ball was randomly changing shape between rock, papers and scissors. If you wanted to catch it, you didn’t only have to be at the right place at the right time, but your hand also had to be in the right complementary configuration to catch the shape-shifting ball.
  • Now that we’re talking about dreams: I finally saw Inception and was completely blown away. It’s not about being complicated, it’s about being a well-told story and a fantastically filmed movie. What I positively adored, is the fact that Nolan doesn’t require much: He only needs you to believe that dreams can be shared, without giving away too many of the details of the mechanism, and then builds a marvellous story on that canvas. My absolute favourite scene was the waking up on the plane, just before the landing, almost at the end of the film. I loved the way in which the characters looked at each other, and the possible interpretations of their expressions.
  • On the topic of the Underworld gig in the Heineken Music Hall: I hope I have my voice back before my morning lecture tomorrow morning. Thank you Fantastic Friends!

That’s it kids. If you’ve come this far, you’re now mostly up to date. Please leave me a comment, it’s good for my serotonin! I hope you have a great week. To get you off to a  good start, here’s a music video showing what an infectious idea could look like…

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Teaching InfoVis in Stellenbosch

Posted on November 21, 2010 by cpbotha| 1 Comment

In week 40 (that’s Monday October 4 to Friday October 8 for those of you not so much into week numbers) I had the privilege of giving a week-long Information Visualisation course to a group of post-graduate students (a mix of B.A. Honours in either Socio-informatics or in Decision-making and Values Studies) at the Centre for KDD of the University of Stellenbosch in the building previously-known-as “The BJ”.

With this post, I want to summarise, extremely compactly, my impressions:

  • In spite of the odd publication at an InfoVis venue, and in spite of putting significant effort into broadening my horizons also into InfoVis, I’m strictly speaking still a Scientific Visualisation (SciVis) guy. In this context, developing and giving an InfoVis course was a fantastically educational experience. I aspire to be equally fluent in SciVis and InfoVis when I grow up.
  • I designed a course based on a mix of lecturing, paper reading and discussion and hands-on exercises. I can now highly recommend this combination. Next time I will put more effort into involving everyone more actively in the discussion. What also seemed to work well was the course website that students could add their work to during class.
  • I sourced almost all of my material from generous InfoVis colleagues, primarily Dr. Tamara Munzner, but also Dr. John Stasko, Prof.dr. Jarke van Wijk and Dr. Maneesh Agrawala. Thank you!
  • Having spent 7 years at the Stellenbosch Engineering Faculty (1500 guys all wearing t-shirts in jeans; furthermore, social skills are frowned upon) and the past 10 years at the TU Delft, a kind of Ultra-Engineering-Faculty, spending the week at The BJ interacting with socially adept and skilled communicators was a truly interesting experience.
  • I was otherwise also impressed with the level of cooperation between the students and their willingness to work hard (and long).
  • Laptop-use during lectures in a relatively small class: It’s an interesting phenomenon, having to deal with your own little communication backchannel. Banning laptop use is obviously not an option as there are too many possible advantages, but I’m not sure yet what a good solution would be towards making sure that the laptops are being used to augment learning.
  • Most students chose ProtoVis (from a list of 8 possibilities, and they were free to use anything else too) to implement their final mini-projects with. This was probably due to their previous web-programming experience, and also that ProtoVis requires more or less zero setup.

Conclusion: Much learned, hopefully the students did too. :) All in all a positive and energising experience!

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VCBM 2010 [Weekly Head Voices #26]

Posted on July 8, 2010 by cpbotha| 1 Comment

(This post is a slightly longer than average report detailing our trip to the EG VCBM 2010 conference. It’s of course super-entertaining, but if you still do wish to skim through it, I’ve bolded the per-paragraph themes. If you’re not sure what these danged conferences are about, see my recent EuroVis 2010 post for a general introduction.)

Last week, I accompanied Peter Schaafsma (he of the orbital fat mobility paper), Bastijn Vissers and André van Dixhoorn (they of the resting state fMRI brain connectivity paper) to Leipzig, where they had been selected to present their work at the second Eurographics Workshop on Visual Computing for Biology and Medicine (VCBM).

Pretty VCBM logo.

Things got off to a great start when, as we were travelling there by speeding bullet (okay, it was just a brand-new rental Opel, but the Autobahn turns any car into a Speeding Bullet!), we managed to strike, at high speed, a high-quality German plastic bucket that had suddenly appeared right in the middle of the road. After a few more kilometres of noticing that our speeding bullet was not able to pass the very slowly accelerating bullet stage and was making strange disconcerting noises to boot (excuse the automotive pun), we stopped to investigate, noticing to our shock that the bucket, having been very badly burnt, Mustafa-style, was still lodged under the car.

After carefully dislodging the remaining half of the bucket, we were even more shocked to notice that the car was dripping concerning amounts of liquid more or less from the spot where the bucket had been stuck. Further on-site and online investigation by the crew brought to light the following observations: 1) The liquid was not hot, and so probably did not come from the engine. 2) The liquid was tasteless (don’t ask). 3) The air-conditioner had been running all the time, and certainly would have to get rid of water condensate from the cooled air. This latter observation was to us not immediately obvious, but now is, and hopefully to you as well: Automobile air-conditioners often get rid of condensed water through outlets under the car. Phew.

Our speeding bullet tore through the remaining 200 kilometres in record time, where my man Helmut from Vienna and these wonderful brain-boosters were waiting for us on the Nikolaikirchhof:

Leipzig's famous 1 litre brain boosters. Image deliberately deFaced. The arms in the photo might or might not belong to anyone that you know.

The conference kicked off the next morning bright and early with a brilliant keynote by Prof. Anders Ynnerman.  This was related to the great talk he gave in Delft the week before, but even better, as, amongst other things, he had had the Virtual Autopsy multi-touch table shipped all the way to Leipzig to be able to demo live during his presentation. He even managed to undo the evil our projector in Delft had wrought on his laptop’s colour profiles and finally showed his visualisations in their full glory on the projector in the Mediencampus Villa Ida.

The second keynote, given by Dr Roland Bammer, focused on their work on eliminating motion artefacts in brain MRI, both by image post-processing but also, and this is the really cool bit, by mounting a special marker on the forehead of the subject that allows real-time 3D motion tracking and linked real-time low-level correction of the MRI acquisition process. They are currently working hard on getting their tech into users’ hands. Help them by bugging your local Radiology Department about this! :)

The multi-touch virtual autopsy table was available throughout the conference to try out. Two observations: 1. Sometimes the glass surface of the multitouch.fi table is harder to work with than the MS Surface's matt finish. 2. It's hard to use the table in environments with too much lighting.

The rest of the scientific program was perfectly varied, consisting of paper presentations, an invited talks session and a posters session, including a plenary fast-forward where each poster author was given three minutes to promote their work.  What really shone throughout the two days, was the superb organisation in Leipzig: Thanks to Dr Alex Wiebel and colleagues, the conference was a text-book example of conference organisation, with each event occurring at exactly the right time, not a moment too soon or a moment too late.  The Mediencampus Ida Villa was the ideal location for the conference, not in the least due to its air-conditioned auditorium shielding us from the more than 30 degrees Celsius outside temperatures. Another important manifestation of the superb organisation were the magical coffee breaks, always taking place exactly when you needed them, with copious amounts of cookies to boot!

Erik Pernod and Herve Delingette won the VCBM 2010 Best Paper award with their paper titled Interactive real time simulation of cardiac radio-frequency ablation, really great work combining elements of simulation, visualisation and a clear clinical application.  The best paper committee had a relatively easy choice, as the reviews (3 to 4 per submission) were also unanimous about this paper’s ranking. As an added bonus, the work is available within the open-source SOFA framework.

My personal and completely biased Head Voices VCBM 2010 Best Talk Award however, goes to the invited talk by Marc Streit and Alexander Lex on Caleydo: Visual Analysis of Biomolecular Data. The presentation was an extremely entertaining show by two skilled speakers, striking just the right balance between focus and variety as they demonstrated several aspects of their Caleydo visual analysis software.  At several points, for example the explicit visual linking of different heterogeneous data sources (paper here, youtube video here, see here for other publications.), I had the typical reaction to good scientific contributions: Now why didn’t I think of that?!

Three to four of the VCBM 2010 papers (this includes the best paper of course) will soon be selected to submit an extended version to the forthcoming special issue in the Computers and Graphics journal on Visual Computing for Biology and Medicine.  Very importantly: Everyone is welcome to submit an aptly themed paper to this special issue! See the C&G special issue on VCBM call for papers for more information.

On a more personal note: This was the second VCBM workshop, with the first having been held in Delft in 2008, organised by yours truly. It was really great in Leipzig experiencing the growing community around this event and especially connecting with some of my favourite people. I’m greatly looking forward to future VCBM workshops, which makes it doubly cool that  VCBM 2012 will be hosted by Prof. Anders Ynnerman in Linköping (Sweden) and that after that, it will become a yearly phenomenon.

Will you join us?

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