Dear DAVID Community,

As you are probably aware, the entire DAVID company, team and product range has been integrated into HP Inc.
This forum is now read-only. Relevant content has been migrated to HP and merged into HP's Support Forums on November 1, 2016.

To start new discussions for 3D Scanning, please register and post your new topic at the HP Support Forums

Calibration fails everytime

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

Calibration fails everytime

Postby magliott » Mon Mar 22, 2010 2:40 am

Been trying to calibrate the camera with no luck. I even upgraded the camera in case that was the issue, from logitech stx to the logitech pro 9000 and adjusted all camera setting to get this image.

I've tried including all the dots and croping some of the dots (as in this image) in the camera view, but consistently get 'calibration failed' almost right after I hit the calibration button. Seems like the software doesn't even think or analyze the image before it gives me the fail notice.

I tried to go into the advance settings to get additional help, and I get no new information from it. I try to use the erase, but it gives no indication i'm erasing anything. Manual calibration is the same result as erase (no indication i'm clicking on anything).

the boards are at 90 degrees, the paper is flat, the dots look clear on the video capture... I'm running out of ideas... can someone please shed some light onto what could be wrong?

thanks
mags
Attachments
Clip.jpg
screen capture of my camera view
magliott
 
Posts: 3
Joined: Sun Mar 21, 2010 10:35 pm

Re: Calibration fails everytime

Postby funtasma » Mon Mar 22, 2010 10:32 am

Is the hight level of left and right panel the same? It seems to me that the left panel is a little higher than the left, but it can be an optical delusion.

Otherwise I would just reinstall the software.

-Benjamin-
funtasma
 
Posts: 148
Joined: Wed Oct 07, 2009 1:39 pm

Re: Calibration fails everytime

Postby magliott » Mon Mar 22, 2010 7:13 pm

thanks benjamin,

i will try to even out the left and right panel a bit more so it appears correct in the camera view.

but is it typical that no sign of the calibration being attempted occurs when dots are misaligned?

Also i was wondering if the warping of the dots due to wide angle viewing of the camera could be the problem. May try to move the boards further back and then zoom in to crop in close to the dots.

I've tried to previously reinstall the software twice. No luck on getting a better calibration.

thanks,
mags
magliott
 
Posts: 3
Joined: Sun Mar 21, 2010 10:35 pm

Re: Calibration fails everytime

Postby MagWeb » Mon Mar 22, 2010 7:32 pm

Don´t know why, but for me, less contrasted images using V3 patterns worked better with the Pro
MagWeb
Moderator
 
Posts: 2499
Joined: Wed Jul 18, 2007 8:48 pm

Re: Calibration fails everytime

Postby Francois » Mon Mar 22, 2010 9:20 pm

MagWeb wrote:Don´t know why, but for me, less contrasted images using V3 patterns worked better with the Pro


I agree. That's what I have experienced here too.
Francois
 
Posts: 60
Joined: Sun Feb 14, 2010 6:09 pm

Re: Calibration fails everytime

Postby Sven » Tue Mar 23, 2010 10:43 am

Hi
I cropped your camera image from the screen shot you have posted. It is very small and calibration failed. Then I scaled it up by factor 2 to 794*594 and calibration worked fine!
test.jpg

I am wondering, in your screen shot the camera image is not in DAVID's window but in some QuickCapture image? Of course DAVID needs access to the image data ... So you need to close all other camera viewers before you select the camera in DAVID. (Sorry if I am getting this wrong).
Sven
User avatar
Sven
DAVID Developer
 
Posts: 1541
Joined: Mon Jan 22, 2007 8:59 am
Location: Braunschweig, Germany

Re: Calibration fails everytime

Postby tkameroski » Thu Mar 25, 2010 2:37 am

I am having the same problem. I recreated the panels four times and still not calibration. When I use the old pattern, it works every time. Does the log shred any light on what problem it is encountering?

Image
tkameroski
 
Posts: 1
Joined: Sun Mar 07, 2010 9:51 pm

Re: Calibration fails everytime

Postby Francois » Thu Mar 25, 2010 8:58 am

Hi Sven,

Maybe these should be in the wish list, but since this post is about failing calibration, it's probably appropriate too :

I am using only the new panels.
- Is it possible to have an option to disable the test for old panels when the calibration fails, since that's going to fail anyway and it's taking time when you try to calibrate many many times ?
- When the calibration fails, the debug window doesn't currently give, to us non-experts, some clear understanding of why the calibration fails. Could we better/simpler descriptions of the reason ? Or maybe you could provide a list of all of the possible error messages with some explanations on the side ?
- Yes, the calibration is sometimes very frustrating. So far, I have done a lot of successful calibrations with various setups/resolution and I think I know what I am doing. But yesterday, I spent about 2 hours to try to calibrate at 1600x1200. No way ! And the points were correctly located/positioned on the screen. Had to revert back to 1280x1024 ... 8-(( ... That's why clearer error messages would be very helpful.

Thank you
Francois
 
Posts: 60
Joined: Sun Feb 14, 2010 6:09 pm

Re: Calibration fails everytime

Postby Sven » Fri Mar 26, 2010 12:23 pm

Hi tkameroski and Francois,

The new pattern is still new, so experience from the field is very valuable. I have been playing around with it and found it very robust, even with "difficult" images, but of course I could not test everything. Please post or send me your camera images that you have during calibration, which you think should calibrate without problems. I may be able to help you or improve DAVID. :D

Thanks
Sven
User avatar
Sven
DAVID Developer
 
Posts: 1541
Joined: Mon Jan 22, 2007 8:59 am
Location: Braunschweig, Germany

Re: Calibration fails everytime

Postby Francois » Fri Mar 26, 2010 10:00 pm

Hi Sven,

Sven wrote:Please post or send me your camera images that you have during calibration, which you think should calibrate without problems.


Thanks for the answer.
Do you mean just a screen copy of what the camera sees during the calibration ? Is that enough to diagnose what the problem is ?
If yes, I will do so.
As a start, there is one thing you can try that didn't work for me :
- calibrate at 1280x1024. do it several times to make sure the settings are not borderlines
- switch to 1600x1200 and try to calibrate without changing anything else like light, contrast ...
- If that keeps failing, go back to 1280x1024 and try again. That should normally work, right ?
- Then go back to 1600x1200 and try again. Eventually play with the settings. I was never able to get the calibration with that resolution, no matter the settings I had.

Kind regards
Francois
 
Posts: 60
Joined: Sun Feb 14, 2010 6:09 pm

Re: Calibration fails everytime

Postby Francois » Sun Mar 28, 2010 10:23 pm

Hi Sven,

Sven wrote:... Please post or send me your camera images that you have during calibration, which you think should calibrate without problems. I may be able to help you or improve DAVID. :D


Here is one that I was able to calibrate only one time at 1600x1200 (luck ?) after many many trials. I tried again many times after that too without success. I tried all kind of light/contrast settings but that didn't help.
This screenshot is 1280x1024 but the camera setting was on 1600x1200.
If possible, I would appreciate to receive answers to my previous posts in this thread.

Thank you
Attachments
Plans.JPG
Francois
 
Posts: 60
Joined: Sun Feb 14, 2010 6:09 pm

Postby hal » Mon Mar 29, 2010 10:28 am

Hello Francois,

I've tried to download your latest attachments, and don't work for me, too. But if I try to reduce the pixel dimensions of the image, David can calibrate succesfully :?

Now, probably the problem could be the resolution and the camera lens distortion, Sven? I wrote this because I've tried to use the other grabbed image that Francois posted previously, in the first message of March 22, and upscaled in two ways:
- with a low resolution of 794 x 594 I can calibrate succesfully, but the green lines of deviation feedback, are big and with crazy orientations;
- with an high resolution of 1600 x 1197 I can't calibrate, but David find all the right position of red cross on circle's centers (probably because the green vectors check the same error of the low-res test, but multiplied for X value... so the deviation is too big and calibration fail.. maybe).

Seems that the new V3 system of calibration is a little fragile with big camera views. Or maybe because your angle isn't so precise, Francois...
It's strange because I have no problems with my 1024 x 768 camera :roll:
I've tried to test different camera resolutions with some images from 640x480 to 1600x1200.
Just to avoid the problems of distortion from lenses, I've tested with a the virtual camera of 3D Studio Max. And all was ok.
Please, see the images into the attached zipped archive.
Now, with all of these "perfect" virtual cam-views, David have no problems.

So, the problems should be:
- or your 90° angle isn't perfect or panels aren't flat (some distortion in your setup) and David find these errors at big resolution but jump the mistakes at low resolution (but the quality feedback of the green vectors underline big differences between real and expected markers' position);
- or the camera optics distortions + big camera resolutions = calibration fails... so it could be a problem of V3 system.

In the meantime that the problem haven't its solution, I suggest to work with "not so high" resolutions or use the old patterns.
Best,
Mattia
Attachments
V3 Tests.zip
A set of V3 markers at different resolutions
(106.36 KiB) Downloaded 175 times
User avatar
hal
Moderator
 
Posts: 1527
Joined: Thu Mar 01, 2007 4:08 pm
Location: Cavaria con Premezzo (VA), Italy.

Re:

Postby Francois » Mon Mar 29, 2010 1:17 pm

Hi Mattia,

hal wrote:I've tried to download your latest attachments, and don't work for me, too. But if I try to reduce the pixel dimensions of the image, David can calibrate succesfully :?


Thanks for looking at this too.
Yes, I know. I don't have a problem with 1280x1024 other than having to reduce the light/contrast to get a successful calibration. It's just the 1600x1200 that's creating nightmares.

hal wrote:Now, probably the problem could be the resolution and the camera lens distortion, Sven? I wrote this because I've tried to use the other grabbed image that Francois posted previously, in the first message of March 22, and upscaled in two ways:
- with a low resolution of 794 x 594 I can calibrate succesfully, but the green lines of deviation feedback, are big and with crazy orientations;
- with an high resolution of 1600 x 1197 I can't calibrate, but David find all the right position of red cross on circle's centers (probably because the green vectors check the same error of the low-res test, but multiplied for X value... so the deviation is too big and calibration fail.. maybe).

- "... image that Francois posted previously, in the first message of March 22 ... " ??? Which one ?

hal wrote:So, the problems should be:
- or your 90° angle isn't perfect or panels aren't flat (some distortion in your setup) and David find these errors at big resolution but jump the mistakes at low resolution (but the quality feedback of the green vectors underline big differences between real and expected markers' position);
- or the camera optics distortions + big camera resolutions = calibration fails... so it could be a problem of V3 system.

In the meantime that the problem haven't its solution, I suggest to work with "not so high" resolutions or use the old patterns.

- My 90° angle is as closed to 90° as I could get it. Not perfect but not far ... 8-) And panels are flat, flat, flat, flat ... 8-)
- That's what I did, I switched back to 1280x1024 but would also like to be able to use the Logitech high resolution
- I don't want to go back to the old patterns as the new ones do not need a full view of the patterns
- I think the calibration process should be a snap for anyone, with no needs to fiddle around with light/contrast providing that they are at reasonnable levels (like a standard B/W image ?). Now, I also know that it's easy to say but more likely difficult to write the corresponding software for that.

Kind regards
Francois
 
Posts: 60
Joined: Sun Feb 14, 2010 6:09 pm

Postby hal » Mon Mar 29, 2010 1:40 pm

Ooops sorry Francois... I mean "magliott", not you.
I've wrote your name every time, but I refear to your and to Mags problem. Sorry.
However the problem is quite similar, right? :D

So probably, reading your latest post, we can suppose that the problem is only about big res and lens distortion... right?
Or maybe the 1600x1200 mode of your cam is interpolated and David have problems... ? :roll:

Mattia
User avatar
hal
Moderator
 
Posts: 1527
Joined: Thu Mar 01, 2007 4:08 pm
Location: Cavaria con Premezzo (VA), Italy.

Re: Calibration fails everytime

Postby Sven » Mon Mar 29, 2010 5:37 pm

Hello,

Thanks, I have used your posted images to investigate. Francois, your latest image caused problems with the light gray noise around some markers. They may have been caused by JPG compression of your screen shot...? Anyway I have tweaked some parameters inside DAVID. Please try this test version: Install 2.5.3 and then overwrite the .exe with the one I have attached here. It should be more robust.
This version also pops up a debug window which contains the markers that the V3 calibration has detected. This may give you a hint what the problem is. But please keep posting calibration images that cause problems!

Please ignore the order (0, 1, 2, ...) of the markers, it's irrelevant at that point. Also please don't try the Manual Calibration with the V3 pattern, it won't work.

Thank you
Sven

EDIT: Deleted attachment... will attach new one soon.
EDIT 2: See next post.
User avatar
Sven
DAVID Developer
 
Posts: 1541
Joined: Mon Jan 22, 2007 8:59 am
Location: Braunschweig, Germany

Next

Return to Camera Calibration

Who is online

Users browsing this forum: No registered users and 1 guest

cron