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Color Correction

January 27, 2011
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For the trolls who insisted that snow is white, here are the color-corrected versions of some of the pictures from the last post. But the light sources were incandescent bulbs, so it actually looked very yellowish from the naked eye.

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Winter Photos

January 27, 2011
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Just a bunch of pictures I’ve been taking during the winter at the MIT:

Siggraph Post-mortem, part 2

January 21, 2011
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Now it’s time to talk about the things that didn’t work so well:

  • File sharing: Yeah, I told that this worked quite well, but we also had our hustles with it. First, we were sharing files with 6 people through Dropbox, and some of them had reached their space limit. Having to delete things in a rush in order to have a new rendered paper updated is not the safest thing one can do. Second, although we used version control for the paper itself, we didn’t want to deal with merging and conflict resolution on Latex files, especially at 4am on deadline’s eve. So, we decided to use a “token” for some of the files, which was a bit messy sometimes. Next time I’ll make sure we use a locking mechanism or a better communication schedule.
  • Communication: although we coordinated things quite well during the process, some things could’ve worked better. First, the mail server of one of our collaborators from abroad stopped working close to the deadline, leaving him almost “isolated” during the last 10 hours. Second, next time I’d make sure we schedule more group meetings through instant messengers, as those greatly improved the overall organization.
  • Prototype building. Although we had some design and building skills, our prototypes could be greatly improved if we had somebody with more experience in hardware dedicated to that task. Our sub-group comprised mostly of computer scientists, which is quite unusual in the camera culture group (most people are engineers or physicists). In the end we had nice prototypes, and the issues we had with technology were all detailed in the limitations section of the paper, but this is something we can still improve.

Of course there are more details, but I really can’t share them at this moment because they are related to the research subject. To finish, I’d like to acknowledge our team and some others who collaborated with the project: Vitor Pamplona, Jan Zizka, Everett Lawson, Ramesh Raskar, Manoel Oliveira and Esteban Clua were directly involved with the project and paper; Pedro Thiago created nice 3d renders to illustrate some concepts, Cintia Bartz was photographed and filmed using the prototypes, which is included both in the paper and as extra material sent to the reviewers; Taya Leary for keeping our lab area full of food all the time; Andy, Doug, Abhi and the others from the Camera Culture group for the comments and the great time we had this season.

Siggraph Post-mortem, part 1

January 19, 2011
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Yesterday was ACM Siggraph‘s deadline for technical papers. Since mid-november I’ve been working on two research projects here at the MIT Media Lab‘s Camera Culture group, eventually expecting to write papers about them during this period, known to us as “Siggraph Season”. One of the projects eventually took off and we were able to finish a nice paper in time, which we hope will be accepted and well received by the community.

Although I still can’t comment on the subject our research, here are some highlights about the process, and the eventual submission of a paper for Siggraph:

  • Good ideas need a lot of time to mature. The best projects, those that eventually get submitted as a paper, normally stay around for some years before getting in shape, some are even revisited ideas.
  • Research doesn’t come out of nothing. We need to put a LOT of effort into reading, understanding and addressing previous work, developing the new idea (from idea to concept, from concept to model, from model to working prototypes), and finally rendering a paper and supplementary material.
  • It’s also a teamwork. There is no way one can do it all alone. First, there’s simply too many things to be done. Second, people have different preferences. In this type of process, every skill can become handful, such as knowing how to use a soldering iron, design a new circuit board, create good audio recordings, etc.
  • It seems odd to spend the last two months working 12 to 14 hours every day (including weekends, christmas, new year’s eve and any other holiday) and end up with a simple prototype, 6 to 8 pages of dense text, a 4 to 5 minutes video and some representative images.
  • At the same time, it’s remarkable how much knowledge and information you can gather, process and absorb in two months, even if you’re applying your skills in new field, one that you’re not very familiar with.

Things that worked for us:

  • Teamwork. We got along quite well and there were no hustles inside the team. Each one had his own rhythm and also preferences, and the process of task assignment occurred naturally at most times.
  • File-sharing. We’ve used both version control (svn and git), and Dropbox, for different purposes and at different moments. For most of the basic work, Dropbox is quite handy, because of its ease of use and ubiquiitousity.
  • Shared writing and pair reviewing. We shared the writing responsibility among three team members, and, in the end, all sections that we initially planned for the paper were written. The reviewing tasks at the polishing stage was done in pairs, sometimes in trios. This was very successful, and I personally think the quality of the final text greatly benefit from this.
  • Early writing and external reviews. We started to write the papers (we didn’t know at the beginning which ones would make it) very early. Invited reviewers that read the early drafts and other collaborators that knew about the project provided valuable comments.

In the next post I’ll talk about what didn’t work quite so well.

Snow Storm

December 30, 2010
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Well, some people may have heard about the snow storm that fell down at this part of the world some days ago, so here is what my experience with it was like.

First, I was working during most of the first night of the blizzard, so I couldn’t see the amount of snow that was accumulating outside, but at 1:00am it was time to go home, and this is what the street looked like:

snow street, Cambridge MA

This is "snow street", near MIT Media Lab. I had to cross it this way.

But since it had already snowed before (just not this much), there was already salt spread through the most important streets and avenues. Given that, some adventurers/drivers were still driving around. This taxi driver, for instance, wasn’t particularly slow.

Crazy TX

Fast taxi at 77 Mas Avenue (MIT main building).

The cold is not so challenging (if you’re well protected as I was), and the view is quite cool to somebody who’ve never seen the snow before (yeah, the freezer doesn’t count).

Snow square

My way home during the snow storm

The other news is that we now have a pet at our lab. It’s a mouse that’s very interested in the leftovers we throw away every night after dinner.

Xmas at MIT Media Lab

December 24, 2010
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Ho ho ho, it’s Siggraph season and everybody is hard at work here at the Camera Culture group. But after all it is also christmas and we (sort of) also celebrate this “holiday” here. This is a report of our attempt to create a thematic decoration at our lab this noon.

First the crew put hands on to make the christmas lights and tree to work. In this picture we can see Abhijit Bendale hard at work with the help of Vitor Pamplona:

Abhijit and Vitor trying hard to decorate the lab

The result was ok, but not very “inspirational”, so we got the help of seasoned christmas-fellow Dr. Ramesh Raskar, head of the Camera Culture group:

Ramesh Raskar fixing the mess

The final result is much more pleasing to the eye now. Notice the detail of the “xmas gift” under the tree:

Merry christmas!

If you don’t believe I’m seriously saying our final design is amazing, see the face of these passers-by when they saw our stuff by chance while visiting the MIT Media Lab:

Passers-by amazed by our christmas tree and lights (and Mr. Snow-singer-man)

Merry christmas!

Feliz Natal!

Siggraph Project Accident

December 16, 2010
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Is light a form of heat? Yeah yeah yeah, of course… Light is made of photon particles, electromagnetic energy, which is directly converted into other energy forms when absorbed…

But it’s also a bit odd when you burn an ant using only sunlight and a magnifier glass (everybody did this sometime as a young child). What about burning a light-mask without even using a lens?

Well, as part of my ultra-top-secret Siggraph project, I’ve been playing with a 600 lumens LED that is very bright indeed. But today something unexpected happened: the mask caught on fire during an experiment! Blame it on the LED:

Light and burnt mask

Burnt mask still in place, on top of a 600 lumens LED

The burnt mask

Detail of the mask after the burning episode

The 600 lumens LED

The vilain: a 600 lumens LED. I was using only one of the two available. Yeah, that's a heatsink.