Fabbri's Blog

Oympics and World cup in Brazil

2009-10-02T18:20:00.000-07:00

The 2016 olympic games will be at Rio! Also, the 2014 world cup will be in Curitiba, Brazil:

Website back up

2009-08-13T10:10:00.000-07:00

My website is back after I took my server out of the lab.
www.lems.brown.edu/~rfabbri
or, during daytime, you can check:
cortex.homelinux.org

Applets - the geometry of 2 and 3 views

2009-05-29T08:56:00.001-07:00

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

2009-05-14T21:36:00.001-07:00

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

2009-05-14T11:04:00.000-07:00

2 colors are enough

2009-05-12T21:59:00.000-07:00

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

2009-04-20T13:41:00.001-07:00

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

2009-03-13T18:47:00.001-07:00

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

I passed prelims!

2009-03-05T13:28:00.001-08:00

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

Video screen shots in Linux

2009-02-11T12:20:00.001-08:00

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.

Ignoring Mortality We Worship Mediocrity

2009-01-23T10:13:00.000-08:00

This video is a good inspiration for us to gain courage to be innovative and bold I'm trying to build up the courage to grow a mohawk -:^) Only then I will feel like I'm truly living up to my ideals.

International Computer Vision Summer School

2009-01-17T09:08:00.001-08:00

... In Italy.
http://svg.dmi.unict.it/icvss2009/index.html

Happy 2009

2009-01-13T21:54:00.001-08:00

Got married in December! I am now a man with responsibilities, another reason I've been studying for my prelims now. Need to finish my PhD! Among the subjects, I've picked differential geometry and complex analysis as a minor. Reviewing math after some motivation from research feels really productive. And, man, times have changed - during my PhD years I've witnessed the rise of core information technologies such as Youtube & Wikipedia (sounds already like grandpa talk!). What great tools to study math with. Check out this video on mobius transformations (related to homographies in projective geometry): Which goes back to support an old point of mine: computer technologies have an explosive (exponential) effect in improving society.

Google indexes magazines and newspapers on Book Search

2008-12-10T12:10:00.001-08:00

http://googleblog.blogspot.com/2008/12/search-and-find-magazines-on-google.html

Optimal 3D Triangulation Code

2008-12-09T20:20:00.001-08:00

The source code (in C) for a recently published optimal 3D triangulation / reconstruction algorithm can be found at:

http://www.iim.ics.tut.ac.jp/~sugaya/public-e.html

The method supposedly does not have the singularities of the widely-used Hartley-Sturm algorithm, and was developed by K. Kanatani, Y. Sugaya, and H. Niitsuma.

Tangorian Giraffes

2008-12-04T18:32:00.001-08:00

VxL code browsing in ViM

2008-12-01T14:16:00.001-08:00

When working with a huge codebase, its nice to be able to browse
through the code lying in different directories.
Most other sites about ctags only deal with files in the same
directory, though.
I use vxl.sf.net, which consists of a huge source tree of C++
libraries, headers, and templates.
Here is my solution:

I installed exuberant-ctags (make sure this is the one in your system),

then I issued the following command:

ctags -R vxl lemsvxlsrc

from the directory containing the vxl source tree 'vxl' and the
internal Brown 'lemsvxlsrc' tree.
This generates a tags file. Now, tell VIM to always use that by
setting a tags search path:

" Set the tag file search order
set tags=./tags,tags,~/tags,/home/rfabbri/cprg/vxlprg/tags

You can add the above line to your ~/.vimrc or, even better, to a file
in ~/.vim/ftplugins/cpp_xxx.vim, where xxx is a custom extension you
choose.

Windows partition deleted.

2008-10-28T12:27:00.001-07:00

Never used it, never needed it, never respected it. Now let me pump up my Linux environment with the Windows carcass left in my harddrive :-)

Pós-doc e Pós-grad na USP

2008-10-28T09:29:00.001-07:00

Altamente recomendado!
Sem duvida o melhor grupo cientifico em que ja estive :)

==========================
OPORTUNIDADES PARA PÓS-GRADUÇÃO E PÓS-DOUTORADO
GRUPO DE COMPUTAÇÃO INTERDISCIPLINAR, IFSC-USP
Outubro de 2008 a Maio de 2009

Comunicamos diversas possibilidades para pesquisa, a nível de
pós-graduação e pós-doutorado, no Grupo de Computação Interdisciplinar (GCI)
do IFSC-USP. As principais áreas de pesquisa incluem mas não se limitam a:
1. VISÃO E IMAGENS
2. INTELIGÊNCIA ARTIFICIAL
3. REDES COMPLEXAS
3. BIOINFORMÁTICA E BIOLOGIA DE SISTEMAS
4. COMPUTAÇÃO DE ALTO DESEMPENHO
5. SISTEMAS DISTRIBUÍDOS E GRIDS
6. REDES DE COMPUTADORES
Os candidatos poderão ter formação anterior em computação, informática,
física, matemática, engenharia, estatística, química ou bioinformática.
Os trabalhos de pesquisa serão desenvolvidos nas respectivas áreas de formação
dos candidatos. As possibilidades de pós-graduação incluem o IFSC (nível 7
CAPES) e Bioinformática da USP (nível 5 CAPES).

PARA INFORMAÇÕES ADICIONAIS, visite a página
http://cyvision.if.sc.usp.br/~francisco/comp_inter/index.html

John Maeda talk at Brown

2008-10-16T19:48:00.001-07:00

The new RISD president, and former MIT Media-Labber John Maeda spoke
today at Brown.

It was an interesting experience, more of a light sequence of simple
facts that did the job of kepping people entertained; I feel nobody
was profoundly illuminated.
But maybe that's exactly the message - life simple facts and tidbits
can be more important than they seem. But at the same time it does
bring a sense of unfulfilment and apathy towards getting
anything explained, nailed down, or thoroughly illuminated. I had a
simple mild positive reaction to it. Simplicity and mediocrity
inevitably must have something in common. Its much like short Tao
wisdom.

One of his little ideas that really shook me was the fact that
technology is kind of saturating in the 21st century, and that what we
really need is more human reality, sensibility, and creativity into
our lives.
That's pretty much true. As a computer vision scientist, I think we
already threw hardware at problems a lot, and although it does bring
insights and immediate results, what we really feel the need for is
some human spark, human care, and human design to actually get
algorithms to be smarter, faster, and solve the innumerous problems
that fundamentally weren't solved before. Yes, like the vision
problem.

A Modern Shiny Execution of 3D Computer Vision

2008-08-29T16:09:00.001-07:00

Using Photographs to Enhance Videos of a Static Scene from pro on Vimeo.

Pics of my dog, Eve.

2008-07-18T19:31:00.000-07:00

She's a Beagle mix, but a very beautiful one probably a Beagador.

Congrats to my Angie

2008-07-02T20:03:00.001-07:00

Angie just told me she scored straight A's this semester. A great feat!

Augmented Virtual Reality in your Phone

2008-05-18T18:35:00.000-07:00

Another awesome application of computer vision being materialized - point your cellphone's camera into the environment, and have it augment the video stream by tagging the buildings, restaurants, and attactions for you:
Enkin on Vimeo.

[linux] CVS server issue + solution

2008-05-14T01:13:00.001-07:00

I was trying to use my computer to serve a CVS repository. Should be
simple as connecting through SSH,
but I was getting the error "unknown command server" whenever I typed
"cvs up -d"

The solution in Gentoo Linux was to re-emerge CVS with the server flag
enabled, which can be done by adding the line "dev-util/cvs server" to
/etc/portage/package.use