Applets - the geometry of 2 and 3 views

These are insightful applets to introduce the concept of epipolar
geometry of two and three views.

http://www.ai.sri.com/~luong/research/Meta3DViewer/EpipolarGeo.html

When you press any key, you can drag the 3D point around and sense how
the geometry changes.

More action in twitter

http://twitter.com/rfabbri
Because the iphone interfaces to twitter rock. And "twittering" to blogger using gmail — like I'm doing right now — just doesn't sound as cool.

RISD GRADUATE THESIS EXHIBITION 2009

2 colors are enough

I posted another video like this a while ago, but I always get amazed at them. I can't help but think how shape and boundaries are enough for vision. I'd like to write up what's the role of the contrast sign in producing these effects. For one, the shadows being black helps a lot. The black traces the robots leave on the street make it look like it is covered in snow. Here is a simple inversion of the video (no sound so you can play them together without interference): Shadows become highlights, and the ground seems to be covered in water instead of snow. It would be cool to have another version of the vid with only the boundaries between the black & white regions.

Google Similar Image Search

This new cool feature allow you to search for images similar to a given image. Let's say you want to search for "apple" - how to search only for the Apple, Inc, not the fruit?

http://similar-images.googlelabs.com/

Hispanic Immigration & Graphic Design

Here's my wife's newly designed thesis website: www.from-both-sides.org/home

I passed prelims!

...and I am now officially back to answering emails.

Video screen shots in Linux

I recently had to do a video of a rotating 3D reconstruction.

The simplest thing that worked out of the box was a utility called recordMyDesktop:

http://recordmydesktop.sourceforge.net

Easy to install & use, at least in Gentoo. The way I used it was simple:

recordmydesktop -x X_pos -y Y_pos -width WIDTH -height HEIGHT -o foo.ogv

play it with

mplayer foo.ogv

Mplayer/Mencoder can also be used to convert it to any other video format if you want, e.g. to AVI:

mencoder -idx input.ogv -ovc lavc -lavcopts vcodec=mjpeg -oac mp3lame -o output.avi

I also need to generate an animated GIF. Here's how:

mplayer input.ogv -vo gif89a:output=output.gif:fps=5 -vf crop=850:562:17:99 -frames 999

If you use the input from the OGV file (not AVI), the quality will likely be better.

You can nonlinearly edit the video by opening the GIF in GIMP and deleting the frames you don't want as layers, then saving it. If you want to alter the speed, make sure you set this during the export and make sure you check the box that tells GIMP to override the default frame delays. You can also use GIMP to crop your video further.

To play your GIF animation, just open it in firefox or any browser.