Pajuaba Gmail wrote:

> Just a side question: There is a guy with a shirt with what looks to be

> a stylized brazilian flag. Is it really? Who is he?



I don't know his name, but he is a member of the Gimp team IIRC.



There were two Brazilians at the hugin presentation on Sunday.



<http://www.photopla.net/070506lgm/>



spot them :-)



Yuv





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Copyright © 2007 Yuval Levy

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Just a side question: There is a guy with a shirt with what looks to be

a stylized brazilian flag. Is it really? Who is he?

Regards,

Rodolpho Pajuaba



Yuval Levy escreveu:

> Bernhard Vogl wrote:

>

>>><http://www.photopla.net/070507sat/>

>>

>>Can you tell us more about it? How did the setup look like? any purpose

>>behind it?  :-)

>

>

> Most people you see in the panoramas are GIMP developers. They were in

> Montreal for <http://www.libregraphicsmeeting.org/> at which we (Pablo

> d'Angelo, Jim Watters, Alexandre Prokoudine and myself) represented

> hugin/panotools.

Bernhard Vogl wrote:

>> <http://www.photopla.net/070507sat/>

>

> Can you tell us more about it? How did the setup look like? any purpose

> behind it?  :-)



Most people you see in the panoramas are GIMP developers. They were in

Montreal for <http://www.libregraphicsmeeting.org/> at which we (Pablo

d'Angelo, Jim Watters, Alexandre Prokoudine and myself) represented

hugin/panotools.



<http://www.photopla.net/070506lgm/>

<http://www.photopla.net/070505lgm/>

<http://www.photopla.net/070504lgm/> (one of them is my first pano with

sound recorded and played)

<http://www.photopla.net/070503lgm/>



The purpose of LGM is to promote Open Source image processing software.



The purpose of SAT, a non-profit where the huge display is located, is

to promote artistic use of new technology. The SAT provides synergies

between academic researchers and artists.



Developers and artists were two major groups at LGM and the SAT was

meant to be the conference's dinner venue. Budget restrictions imposed a

change of plan. Nevertheless SAT organized a little extra for us on the

Monday after the conference ended.



I was scheduled to give a show of VR during the dinner. I met with SAT

prior to LGM to prepare for a show on their infrastructure, but ended up

presenting it on a conventional projector during the dinner.



Nevertheless, the contact was positive and so SAT organized a visit

after the end of the official conference.



The cyclorama happened to be the display technology ready for use, and

which I would have used during the dinner. There are other projects

dealing with other forms of 3D display, including a dome and an inversed

dome called panoscope - though these are more for individual experiences

while the cyclorama, as you can see in the VR posted, is for groups.



What is particularly interesting about the cyclorama is that it is all

built with standard components and that the professor who designed the

system intends to publish it soon under an Open Source license.



The hardware is just a bunch of standard XGA projectors connected to a

bunch of standard networked PCs with basic accelerated graphics. It can

project on virtually anything, in this case on a spandex tissue.



The system is amazingly flexible and tolerant of most variables such as

projector positioning, projection surface shape and luminosity, number

of projectors, etc.



A small system can be set up with as little as three projectors, though

to get a meaningful 360° cylinder it takes 7 or 8 of them, and a full

deployment in this class/size is somewhere around 150K-300K $ without

considering that the lamps have to be replaced regularly and that every

change requires a new calibration.



The system uses a lot of principles known in this community from

stitching panoramas, though in inverted sense: overlap between the

projected images is required; the projected images are split along the

seams (as opposed to stitched when producing panoramas) and blended in

real time according to previous established photometric profiles that

take into account irregularities in shape and reflectivity of the

projection surface.



The system requires calibration, a process that is more complex than for

panorama stitching, though with similar principles. Calibration patterns

  with control points are projected on the surface and captured by a

mirror lens (almost like the donuts of cheap real estate 360

photography) and an HD video camera (though a digital camera could also

be used, it would slow the process).



The projected image is split by the master computer for each individual

projecting computer, which applies the distorsion, luminosity and

chromatic profile to the partial image before sending it to the

projector, synchronized via the network at each frame.



The Cyclorama is one of many research projects financed by the Canadian

government in the field of 3D visualisation. There are other similar

approaches in other parts of the world.



Interesting times ahead

Yuv





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Copyright © 2007 Yuval Levy

Verbatim copying and distribution on other medium than YahooGroup

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Yuval Levy schrieb:

> I was inside it, with a few other people.

> <http://www.photopla.net/070507sat/>

Hello Yuval,



Can you tell us more about it? How did the setup look like? any purpose

behind it?  :-)



Bernhard

I was inside it, with a few other people.

<http://www.photopla.net/070507sat/>



Yuv



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Copyright © 2007 Yuval Levy

Verbatim copying and distribution on other medium than YahooGroup

strictly forbidden.