Itinerant self-service stereoscopic photo automaton… the Stereomaton

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stereomaton
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Itinerant self-service stereoscopic photo automaton… the Stereomaton

Post by stereomaton » Wed Aug 21, 2019 6:06 pm

We wanted to talk about this project here, but the "field report" contest hastened the report.

Our original text has been completely restructured by the Crowd Supply team (and is in my opinion a bit less interesting now), the images are not the more appropriate ones and some legends were changed, but the idea is still there, I guess: https://www.crowdsupply.com/virt2real/s ... tereomaton

If you have any question, I can answer as I am one member of the team who built it.
Another field report will be published more specifically about the design of the case, and I hope it will not be changed so much.
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Re: Itinerant self-service stereoscopic photo automaton… the Stereomaton

Post by Realizator » Thu Aug 22, 2019 6:50 am

Stereomaton, your project is really great! :-)
I see you've used touchscreen connected to GPIO, and curious if there were any issues with it. I've played with non-touch TFT (mentioned here), and it just works with no issues. I hope you will cover your screen connection and settings in your next report.
By the way, if you have a blog, you can post a link to your original articles, and I will share this link in our Twitter too in addition to edited Crowd Supply article.
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Re: Itinerant self-service stereoscopic photo automaton… the Stereomaton

Post by stereomaton » Thu Aug 22, 2019 9:05 am

Realizator wrote:
Thu Aug 22, 2019 6:50 am
Stereomaton, your project is really great! :-)
Thanks. People who have seen it in action in the preparing stages also like it.
The festival takes place in a few days and we hope it will be enjoyed by the public too.
Realizator wrote:
Thu Aug 22, 2019 6:50 am
I see you've used touchscreen connected to GPIO, and curious if there were any issues with it. I've played with non-touch TFT (mentioned here), and it just works with no issues. I hope you will cover your screen connection and settings in your next report.
The next report focuses on the conception and realization of the case.
So (almost) no electronics inside.

The post you mention is one that encouraged me to try to add a small screen.

About its connections, there is almost nothing to say about: just insert it the way described in the documentation into the extension connector and it is finished.
We used this screen : http://www.lcdwiki.com/3.5inch_RPi_Display
They provide a script which does a lot of things to "install" the screen. However, I do not like to execute things without understanding what they do, and after a quick read I saw that a part of it was not adapted to our usage. So I preferred to do it myself.

I checked their device-tree overlay file which looked fine, and just copied (and enabled) it on the StereoPi.
After that, a second framebuffer was available and the touchscreen device also appeared in the list of inputs.
The touchscreen is managed by a specialized chip on the extension board and is accessed via a I²C driver configured by the device-tree overlay.
Surprisingly for a resistive panel, the values are pretty accurate so that we did not have to calibrate it.

We wrote a small (ugly) python script to interact with screen and touchscreen by drawing directly in the (mmaped) framebuffer with cairo, and by getting the touch events with evdev.
So we did not tested it in a full environment, but as the low-level parts work out of the box, it should be good with high-level software as well.
Realizator wrote:
Thu Aug 22, 2019 6:50 am
By the way, if you have a blog, you can post a link to your original articles, and I will share this link in our Twitter too in addition to edited Crowd Supply article.
We only sent it by mail. We plan to add it on our website, but translated in French.
The differences with the submitted last version are mostly formal, in the structure, in the images/legends and in a few details; nothing very important though.
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Re: Itinerant self-service stereoscopic photo automaton… the Stereomaton

Post by stereomaton » Tue Sep 03, 2019 10:13 pm

As the festival is over, we can say that our presentation was a great success.
The visitors were amazed by the 3D and particularly because the photos were taken during the festival itself.

Our first idea was to allow people to take 3D selfies, but actually a very small part of the public wanted to try it. The ones who try totally enjoyed it.
Thus we modified the code to be able to take public photo, which were automatically added to the slideshow displayed on our stand. We photographed a lot of moments on the festival.

Lots of explanations were given about how the stereoscopy works and how the images are projected to the appropriate eyes depending on the technology used, mainly anaglyph, cardboard stereoscope and autostereoscopic screen (a few people asked for information about polarized cinema or parallax barrier of the 3DS too).

Everyone was so surprised by the 3D that they did not notice the defects in the photos of our prototype.
There is a big room for improvement, and the first one is probably to be able to frame precisely, but this first public version worked remarkably well!
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Re: Itinerant self-service stereoscopic photo automaton… the Stereomaton

Post by Realizator » Wed Sep 04, 2019 11:44 am

stereomaton wrote:
Tue Sep 03, 2019 10:13 pm
As the festival is over, we can say that our presentation was a great success.
The visitors were amazed by the 3D and particularly because the photos were taken during the festival itself.
Cool! :-)
stereomaton wrote:
Tue Sep 03, 2019 10:13 pm
Our first idea was to allow people to take 3D selfies, but actually a very small part of the public wanted to try it. The ones who try totally enjoyed it.
Thus we modified the code to be able to take public photo, which were automatically added to the slideshow displayed on our stand. We photographed a lot of moments on the festival.
Yeah, pivots are everywhere! We are also prefer to do real field experiments, as in most cases reality does not fits our expectations, specially for human reaction.
stereomaton wrote:
Tue Sep 03, 2019 10:13 pm
Lots of explanations were given about how the stereoscopy works and how the images are projected to the appropriate eyes depending on the technology used, mainly anaglyph, cardboard stereoscope and autostereoscopic screen (a few people asked for information about polarized cinema or parallax barrier of the 3DS too).

Everyone was so surprised by the 3D that they did not notice the defects in the photos of our prototype.
There is a big room for improvement, and the first one is probably to be able to frame precisely, but this first public version worked remarkably well!
I'm glad you and HAUM participants enjoyed this stereoscopic experience! I also retwitted HAUM's message with one stereoscopic photo. By the way, is there any chance for me to obtain a set of 3D photos you've taken? I'd like to publish them!

p.s. As I wrote you in a personal email, a parcel with your Summer prize for Stereomaton field report has been shipped!
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stereomaton
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Re: Itinerant self-service stereoscopic photo automaton… the Stereomaton

Post by stereomaton » Thu Sep 05, 2019 2:32 am

Realizator wrote:
Wed Sep 04, 2019 11:44 am
Yeah, pivots are everywhere! We are also prefer to do real field experiments, as in most cases reality does not fits our expectations, specially for human reaction
For sure. It is always interesting to see how our creations are used by the public, and sometimes it is surprising.

Actually, we have now the two modes (public and private) and the photos are saved in separate folders depending on it. The people who tried the selfie way were super excited and enthusiastly asked how to get the photos and how to display them at home.
Realizator wrote:
Wed Sep 04, 2019 11:44 am
I'm glad you and HAUM participants enjoyed this stereoscopic experience! I also retwitted HAUM's message with one stereoscopic photo. By the way, is there any chance for me to obtain a set of 3D photos you've taken? I'd like to publish them!
Most of the people who enjoyed the experience were the visitors of the festival. We did not have time to count or to take photos, but I would say that we saw between a few hundreds and a thousand people on our stand (the tiny portion were around 50 people for selfies). We spoke a lot and had to drink often.

Except for some redundant photographs and a few very bad ones (and of course the selfies), the photographs are already published here: https://photos.haum.org/albums/teriaki2019/

As you can see, the left chip has significant color shift despite the automatic white balance algorithm applied (that corrects the initial shift which is far bigger) and some parts are very blurry. We did not search the cause of these two big defects yet, but if you have any idea it might help to improve the prototype.
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stereomaton
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Re: Itinerant self-service stereoscopic photo automaton… the Stereomaton

Post by stereomaton » Thu Sep 26, 2019 4:51 pm

You probably have read the article about the design of the case:
https://www.crowdsupply.com/virt2real/s ... tereomaton
Again, I can answer your questions here if you have some.
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stereomaton
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Re: Itinerant self-service stereoscopic photo automaton… the Stereomaton

Post by stereomaton » Wed Oct 16, 2019 7:49 pm

For completeness, I should add the link to the third part of the series which talks about the usage during the event:
https://www.crowdsupply.com/virt2real/s ... -goes-live
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