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Carved Callibration Pattern

The place for questions, problems, comments and tips regarding the camera calibration.

Carved Callibration Pattern

Postby ArchaeoPhoto » Mon Feb 01, 2010 11:25 am

Hi,

is it reasonable to use a cnc-machine to carve a callibration pattern?
I have a material that has a white-black-white coating. The idea is to use a 2-axis cnc and carve out the points.
Questions is: Does it matter that the points have a small depth? About 0,2 to 0,5 mm?
The callibration is done via pattern recognition, right? So it shouldn't matter I thought.

The ends of the carved boards would be cut at 45° each to form a hopefully precise 90° angle.
For scans with background, the boards would be flipped to their backside so that there is a blank surface.

Any comments or suggestions?

Thorsten

p.s.: the boards will fit into a "callibration box" quite similar to the one Hal uses
See here http://www.david-laserscanner.com/forum/viewtopic.php?p=3918#p3918
Laser: Green 5mW & 15mW focusable laser; Cam: Color CCD 1280px + Computar 8mm Lens; PC: HP Laptop with 8Gb RAM; Software: David Pro USB, Meshlab, Blender, PS CS4
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Re: Carved Callibration Pattern

Postby MagWeb » Mon Feb 01, 2010 11:33 am

Hi,

no problem with engraved patterns.

tested and done several times since I used this technic on my micro scanner setup.

0.2 mm depth are more than enough to keep the color but the whole engraving must be colored (also its flanks).

I filled my last patterns with a black filler, which was finally smoothed with fine abrasive paper

Gunter
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Re: Carved Callibration Pattern

Postby Sven » Mon Feb 01, 2010 1:09 pm

Hello,
Yes for DAVID it's only important that the markers are well visible (black on white or white on black).
But I suggest you wait a few days, we are going to release very soon (hopefully) a new version with an improved calibration method. The pattern is different.
If you don't want to wait, no problem, the old pattern will still be supported.
Sven
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Re: Carved Callibration Pattern

Postby ArchaeoPhoto » Mon Feb 01, 2010 1:41 pm

Thanks Gunter and Sven for the fast replies,

Ok, I will wait for the new calibration pattern and test it when it's released. There's no hurry :D

It's totally great how DAVID software is evolving. Thanks a lot for this great piece of software!

Best greetings,

Thorsten
Laser: Green 5mW & 15mW focusable laser; Cam: Color CCD 1280px + Computar 8mm Lens; PC: HP Laptop with 8Gb RAM; Software: David Pro USB, Meshlab, Blender, PS CS4
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Re: Carved Callibration Pattern

Postby funtasma » Mon Feb 01, 2010 10:15 pm

Hi Sven,

will you consider to supply patterns for HD-resolution as well, so that we don't need to recalculate the standard ones?

Thanks!

-Benjamin-
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Re: Carved Callibration Pattern

Postby Khalid Khattak » Tue Feb 02, 2010 4:54 am

Hi Sven, nice to know you are improving the software.. currently It is very difficult to make 90degree calibration panel.. My scanning results are fine but i am getting trouble in alignment of 360 degree scan..my final scan is somewhat out...Do you still consider 90degree panel in new calibration design...Can you post some pics..pls
PC: Dell Inspiron i3, 2.27GHz,4GB RAM,64 bit windows 7
CAMERA:
David CCD Mono USB
LASER:
David 5mW Green line laser
PROJECTOR:
3D LED Mini Projector 250lumens, Native 1024x600
[b]http://free3dscans.blogspot.com/
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Re: Carved Callibration Pattern

Postby Sven » Fri Feb 05, 2010 7:27 pm

funtasma wrote:will you consider to supply patterns for HD-resolution as well, so that we don't need to recalculate the standard ones?

The pattern can be used for any resolution or aspect ratio :D
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