Turn around scanner

[WalterMo]

Hi,
Sometimes it is advantageous if the object is stationary and the scanner „rotates“ around it. This is specially the case if the object is a living one. E.g. to scan a foot or a head from different positions requires that the person moves itself as less as possible.

The idea for this around scanner was born here:
viewtopic.php?f=6&t=3289&p=18491#p18491

In the meantime I have built the scanner, mainly using components from a DIY market. My goal was to build it as universal as possible. Therefore it has a lot of versatile adjustment options.

Some SL scans, not of an old boot, will follow.
Maybe later on I will attach a motor to turn the rig.

Walter

[hunkatibor2]

Hi
http://www.david-laserscanner.com/forum/download/file.php?id=4100&t=1
thank you for the indication. I build up my own solution.
Tibor

[hunkatibor2]

Hi Waltermo
http://www.engadget.com/2011/08/09/microsofts-kinectfusion-research-project-offers-real-time-3d-re/
The solution comes automatically. The digitisation of orthopaedic foot is my task. Under very short time . There is a solution :http://www.corpus-e.com/e/produkte_anwendungen_lightbeam.html
The problem the server contact , works so only
Tibor

[hal]

Hello Walter,

Wow, very nice solution! For scanning of living being it will be great.
My only doubt is about the shaking of the entire rig: the only central pivot/constraint is quite far from the camera and projector, and the alluminium structure seems quite long and big. Did you notice about issue with shakes of the rig, during scanning? Maybe a small rubber wheel under the vertical frame, can help...

Keep up your great work and post soon the boot's scans, please.

Mattia

[WalterMo]

Hi,
In the meantime I have carried the sunshade pedestal inside our house. It's filled with concrete and is really heavy.
A shaking is only noticeable (for some seconds) just when the rig was turned. But the important connection between camera and video projector is very stable.
Nevertheless it's a good idea to mount a wheel at the end of the arm.

The scanner which was mentioned above by hunkatibor2 seems to be also equipped with a wheel. Or is it a shadow on the photo?:
http://www.engadget.com/2011/08/09/micr ... ime-3d-re/

Maybe I will add a wheel if I attach a motor to turn the rig. Or, another idea, why not to kill two birds with one stone. Means to connect the motor with the wheel.

Walter

PS. Specially for Mattia: Mats will be very glad to use the rig as a merry-go-round.

[hal]

Yes! so a double machine: scanner and toy! gooood!
Motor on the wheel... mmm, good idea. But whe you program the controller, you must to calculete the right amount of seconds first to start the scan (and wait that the rig will be completely stand).

Regards,
Mattia

p.s.: I think that in the photo, the "shadow" is a wheel, like one that we usaully find on the office chairs. Because that rig will be too much thin.

[WalterMo]

@hunkatibor2:
Sorry, I don't know how the scanner above works. I guess, because of the colours red, green and yellow that the different channels of a colour camera are somehow used. The arm with the camera rotates under the platform where the woman is standing on.

@All:
I have just made SL scans of a low shoe with the turn around scanner. The shoe was stationary and the rig was rotated for 8 positions à about 45°. Both laces were free-hanging. I hadn't made additional scans from top and bottom. And on the suggestion of Mattia I have mounted a wheel from an old office chair at the end of the horizontal arm. Yes, it's a bit shorter shaking now.
Some additional infos:
Video projector Acer K11, Modified WebCam Logitech C600 at 800x600@15fps. Single scans: No smoothing, 2x interpolation.
Only the horizontal stripes were used for scanning, means about 6sec for each scan. "Convex" calibration corner.

DAVID 3 Beta09.
Settings:Frequency=8, Phase Shifts=5, Pattern Holding Time=300, Fusion=650
Only the alignment of the single scans was made with DAVID 2.6.3 because it is more familiar for me.

Walter

[hal]

Perfect!
Great scans, dear Geocentric Walter. A real anti-Copernican scanner!
So, now I'm confused: I thought that was the Earth to rotate around the Sun, but you demostrate that is the Sun that turn around the Earth!

Mattia

[WalterMo]

Hi Mattia,
Tanks for your compliments, but it's not perfect because the scans from above and from bottom up are missing. I only want to demonstrate how it could be done.

This is the first try to scan my right foot. But the conditions were not the best, I was sitting on a too narrow platform of a A-formed aluminium ladder.

Walter

PS. I still believe that the sun orbits the earth. And our planet isn't a disk nor a ball, but a hollow sphere where we are living in! You can check it yourself: Look under your shoes. Where is the sole worn down? At the front and at the back. That's the evidence.

[WalterMo]

Here we have Sven's left foot. We made 7 scans á about 45°.

He was sitting a bit more comfortable than I yesterday. Means on the top of a tower built-up by four crates of a good German beer.
The high position was necessary because I don't want to saw down the steel tube which is coming out of the sunshade pedestal.

Walter

[hunkatibor2]

Hi
Huge result . From an orthopaedic viewpoint the time would interest . How many minutes are the full examinations??
Tibor

[WalterMo]

From an orthopaedic viewpoint the time would interest . How many minutes are the full examinations??

Hi Tibor,

I measured these single times during the foot scan:
1) SL scan with 19 different horizontal stripe patterns: 6 sec.
2) Time that DAVID needs to calculate the scan: 17 sec. During this time the rig can be rotated by hand to the next position. And if the rig vibrates after stop, it can „calm down“.
3) Saving of the scan: 8 sec. Then start of the next scan.

Totalized: 31 sec for one position. We had used 7 positions, therefore 7 x 31 sec = 217sec.

Walter

[hunkatibor2]

Hi Walter
Thank you for the detailed answer. Shoe maker firm the full foot wants to devote 4 seconds to examination . They need my machine then only.
Tibor

[shoesam]

Walter,

I am still very new to this, and my results are getting better.....

BUT.....they dont come close to being as perfect as yours.!!!!!

My generic questions would be:

What is the resolution of your Camera and equipment? ( resolution and RMS error on calibration)

How much effort and software was used to align and fuse your scans???

Love to Know!!!

Sam

[WalterMo]

Sam,
Both feet were scanned with the same resolution and equipment like the low shoe before.
Also the used softeware was the same.
Sorry, RMS error, what do you mean?

Effort: Difficult to say, I needed about half an hour for the alignment and a cup of tea with a lacing of rum .

I am very curious how Tibor will do a wraparound-scan of a foot in 4 sec.


Walter