The Beauty Of The Earth's Surface

NASA's Shuttle Radar Topography Mission measured the earth's surface elevation in february 2000 using radar interferometry. The resulting data is available to the public and can be used for various purposes. I have been playing with the data over the last days and experimented with different methods for visualizing terrains in 2d and 3d, primarily in the context of Openstreetmap rendering. However, nothing has impressed me more than the very first plain grayscale image I produced (showing the area around and to the north of Vienna):



(click for a slightly larger version)

I have never seen so clearly the details and variation of the earth's relief. On most maps, data like this is rendered in the background to give the viewer a sense of depth, but map graphics and surface textures are usually layered on top and take away a lot of the clarity that is so stunning here. One has to consider that the image shows an area that is usually considered to be rather "flat" - but look at how one can see the thousands and thousands of years of wind and rain working on the "Weinviertel" area to the north. Or look at the sharp edge of the "Wienerwald" area, suddenly dropping down to the really flat plains of the "Tullner Becken" and "Wiener Becken".

I considered adding some labels and paths as means of orientation, but then I liked the idea to leave it like it is as a puzzle for you to figure out the locations of places you know in the image.

Addendum: In the light of the current issue of "protecting the planet", pictures like these make me quite confident that the planet will do fine - even long after we humans managed to remove ourselves from it after a short, rather irrelevant episode of civilization...

Augmented Reality in “Print 2.0”

It's nice to see a project I have been involved with going live: The October issue of Red Bull's “Red Bulletin” magazine features augmented reality content that supplements the printed articles. But see for yourself:



Two groundbreaking new features made this move of augmented reality into mainstream media possible. Markerless tracking technology, developed by my former colleagues at TU Graz, allows the system to identify and locate pages in the camera image without requiring special layout or patterns on the page. And even more important, implementing the base technologies in Flash (done by Imagination in Vienna) allows end users to explore the content within their browser, requiring only a webcam connected to or built into their computer. If you want to try for yourself, grab a copy of the magazine and go to http://en.redbulletin.com/print2.0 (or to de. for the german version) to see it in action.

I was involved early in the project as a consultant, implementing a prototype to experiment with various content formats and bringing together the right people to realize the project. It was clear that Red Bull as a customer would require a seamless and direct user experience to suit their brand, and fortunately some of my former colleagues at Vienna University of Technology are now among the top players in the worldwide augmented reality research community and were able to deliver the necessary technology. I am quite happy how this worked out, as it was an important step for me to move away from doing a lot of implementation work by myself to a more conceptual level, bringing together people and using my experience to move the project in the right direction early on.

Although I am happy to see the results, I also see augmented reality, even in this very simple yet compelling form, still suffering from the same problems and obstacles like when I first experimented with it several years ago: Lighting (the real, not the virtual) is incredibly important and difficult to get right, because reflections on the page can make tracking impossible (especially in glossy magazines like Red Bulletin). In low lighting, the noise from the camera makes tracking impossible. Furthermore, the performance of the Flash implementation is a little below my expectations, requiring the application to use a camera resolution of 320x240 (!), further diminishing tracking and image quality. I believe there is a lot of potential for improvement here by optimizing either the implementation or Flash itself. (Hey Adobe, please note this down and check what you can do to optimize. And while you're at it, please add multi-threading capabilities to Actionscript if you want to see killer applications like this with decent performance - in a future of heavily parallelized systems this will be inevitable anyway.)

Talking about the application itself, this is obviously nothing new. Basically, there is still no more compelling augmented reality application in sight than simply placing virtual stuff on real objects - Flash's built in capability to display streamed videos just adds a very nice content type to it. Worldwide, hundreds of researchers are still looking for the “killer app” that will only be possible with augmented reality (I tried for myself for some years). Until a genius comes up with a truly revolutionary idea, we will have to stick with permutations of ARToolkit's cube demo as the mainstream application - and work on providing stable tracking, good performance (possibly on mobile devices) and a seamless user experience as icing on the cake. If done right, this can be great added value for dead-tree publications.

Here is Red Bull's promotion video for the project:

Playing with Arduino

Finally I found some time to do a little hardware hacking on the Arduino platform. As a quick first project and a first step towards much larger things we are planning at Maschinenring I came up with something that a) makes sense and b) can be done with a minimum of money (€10 if you already have an Arduino) and a main focus on programming: A two-joint articulated plotting robot.

Unfortunately, this picture is a fake :)) but I could not resist using this Escher quote (actually i guess the hand should carry a screwdriver to make it symmetrical but I didn't want to spend too much time in Photoshop for now). The real plotting results are much more disappointing because of mechanical errors which are not really controllable in software (and no, it's not the fault of the cardboard used for building the robot arms) and accumulate to an error of approximately +/- 0.5cm in the output.

Nevertheless, it was a fun project and great for getting back into some hardware-oriented programming and thinking about things like optimizing calculations for integer math. More details (including a video of the robot in action and the Arduino source code) can be found at the Maschinenraum blog.

Heres a picture of the actual output: this should be an orthogonal spiral with a winding width of 1cm. (Sorry for the crappy quality, I only have a webcam for taking pictures right now.)

Because of the low precision I didn't bother to program a way to upload more complex graphics to the robot yet, so output geometry is limited to things one can easily implement procedurally. Send me code if you want something drawn, and I send you an arm-signed drawing from the artist ;).

Empty Inbox!

Usually I sort incoming mails into folders immediately, besides the ones that require some kind of action or a reply, which I leave in my inbox (I sometimes even pull automatically sorted emails back into the inbox if I want to remind myself to act upon them). This means there are always some messages in my inbox, usually between 10 and 30, depending on my workload and other factors. Some of these emails can get very old in there, years in some cases where I just don't find the right mindset for a reply.

I am leaving for holiday tomorrow and wanted to answer some of these long waiting emails before that. The basis was laid already a few months ago when I decided to declare as abandoned some private email threads that have been waiting for multiple years, but now the impossible has happened:


Empty Inbox! I can't remember if this has ever happened before since I started using email in ... 1995 I guess.

How do you handle your inbox?

Jetzt geht's los!

[This is a German post – if you want to receive only English posts, you may subscribe to the english feed]

Proletarier bekriegen sich gegenseitig und fordern, den Ölmultis Steuergeld in die Tasche zu schaufeln:

Telepolis: Massive Streiks in Spanien und Portugal

Manchmal wünsche ich mir schon, dass ein BWL-Gundkurs zur Allgemeinbildung gehört: Wenn der Produzent entdeckt, dass die Preiselastizität für ein Produkt gegen Null geht, wird er den Preis endlos steigern und sich dabei eins lachen. Einziger Ausweg: weniger zu verbrauchen!

syn:wall at ITNOA exhibition

I just finished my first Flex project, an interactive projection wall for the exhibition ITNOA - In The Name Of Architecture. The exhibition brings together projects of students of the three universities in Vienna teaching architecture (TU Wien, Akademie der Bildenden Künste, Die Angewandte) in a self-curated setting. While the projects coming from different universities are presented in different areas of the printed-out part of the exhibition, syn:wall brings all projects together on one surface and creates neighborhood relationships between similar projects using quantitative attributes and tags.


The result of such an exploration can be printed out on a color laser printer and taken home by the visitor as an individual page of a distributed, virtual exhibition catalog.

One thing I learned (again) in this project is how inferior projectors are as an output medium. In a single grid cell of the exhibition, measuring 120 x 45 cm, a whole architecture project can be communicated in printed form, including texts, diagrams, plans and renderings. In the same area of the projected image there are 240 * 100 pixels, which can hold a lousy, pixelated thumbnail of the same project. Therefore I really like the idea of on-demand printing, and I would like to investigate this further in future projects, including producing larger prints with a plotter (something we originally planned to do but could not realize within the given budget and time).

ITNOA will be on until the end of the week, with a closing down party on Friday, the 25th of April (unfortunately I cannot be there on Friday because of two other appointments). It is located in the "Albertinapassage", the underpass under the Ring on the Albertina side of the Opera. ITNOA is also probably the last chance to have a drink at the infamous "Gaudí Bar" there, since the underpass will be closed down shortly after the exhibition. This place somehow always inspires me to get totally wasted every time I am there...

Thanks to Rüdiger Suppin for working on the concept with me and to all ITNOA people who helped entering the project information and crop all the images.

A weekend with the iPod touch

Last week I got myself an iPod touch, because I had to spend money from a grant on hardware quickly and there is currently nothing else that I need. I got it primarily for testing web apps on its mobile Safari browser and to optimize them for its screen dimensions and touch interface. The iPod touch shares the same interface, operating system and applications with the iPhone (which becomes available in Austria tomorrow), but lacks three of its features: cellphone capabilities, camera and Bluetooth - I actually own a cellphone which does all this, so I am quite happy feature-wise, but naturally cannot comment on these aspects of the iPhone.

After a week of use I now want to share some of my experiences and observations with you. The first thing that stunned me is that they ship this thing a-maz-ing-ly fast! I ordered it on Monday afternoon, and on Tuesday early afternoon it was delivered to my door! Next: over at Apple, they know how to package their stuff - the packaging is so nicely done it is really a fetish on its own.

The touch interface is really good for a "wow" from everyone, especially with the nicely done details I admire Apple for: Lists don't just stop scrolling at the end, but you can scroll a bit further and they will elastically go back after you release your finger. Applications zoom into view when you start them, and the thing emits this perfectly designed click sound on every action. Multi-touch is overrated IMHO, since I very rarely use it and would find it more convenient to have a single-finger gesture for zooming (multi-touch always also means multi-hand, which is annoying - you cannot hold the thing and perform a multi-touch gesture with the same hand). The complete absence of haptic feedback also quickly turned out to be a caveat: simply no way of reliably controlling the audio player (volume, next song) while it is inside your pocket - you have to take it out, unlock, look at it, every time you want to change the volume. Also I found especially the volume slider would recognize gestures with my thumb unreliably, which is most annoying when the music is too loud and you have to fiddle around for seconds to be able to turn the volume down. Generally, a few (freely assignable?) physical buttons on the side of the thing would probably spoil the super-minimalistic design but would improve usability a lot for me.

Speaking of design: Maybe my hands are just too sweaty, but after a short time of usage the thing looks really ugly, on both sides. Finger taps and grease all over the screen and the shiny back makes you want to clean it all the time, which really is a Sisyphus thing. So its not exactly the kind of device you want to give out of your hand for business presentations, as everyone will go 'yuck, I'd better wash my hands...'

Interestingly I already had several occasions where the much-appraised tilt sensor turned out to be annoying. Obviously, if gravity doesn't point in the direction of your own 'down' vector, you are in trouble, which happened to me in bed several times. I wanted to browse some pictures before going to sleep, and they all would turn to their sides. The other day, Patrizia wanted to turn a photo to look at some detail, but the photo would just turn together with the device and there was no way of stopping it from doing so. So there are situations where it would be nice to be able to deactivate or override that tilt sensor thingy.

What surprised me is how little you can actually do with that thing, in terms of producing or editing content. You cannot edit song information. You cannot reorder the pictures in a folder. You basically cannot delete anything that's on there while on the go. Speaking of limitations, this brings me to the iTunes software you are forced to use. But I do not want to go into the details here, in short: iTunes on Windows is utter crap! I just hate it, and I will never understand how iTunes got the reputation it has... bleh! I hate it, hate it, hate it, and it will probably be the reason why my iPod will soon sit somewhere collecting dust, because actually they force you to use iTunes with the iPod touch - it is not possible to activate "disk mode" on this device which would allow you to use alternative programs. I guess this also means no chance for Linux users to ever sync their stuff with an iPod touch.

The full meanness of the Apple corporation is revealed when you look at the syncing options for calendars and address books on Windows: Outlook and Windows Address Book are the only supported options. Importing bookmarks only from Internet Explorer! No Mozilla, no iCal, no standards support. They have their deals with Microsoft, and they don't give a dime about standards or open products. But it all comes in a nice package, and hey the user interface is nicely animated, so the geeks are flying for Apple. Pfui!

What really surprises me is that they seem to get away with it, and the competition is screwing up so badly that Apple still, after all these years after the first iPod was released, looks like the only company that understands designing products. It's just unbelievable. Even though I hate this closed, proprietary, unhackable thing for its political implications, I wouldn't want to use any of the alternatives out there I have seen so far.