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Author Topic: "nan" markers and 0 paramaters with image variant calibraiton  (Read 1833 times)

hairyfreak

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"nan" markers and 0 paramaters with image variant calibraiton
« on: December 28, 2021, 11:57:44 AM »
Hi,

I've not used the image variant paramters much before and seem to have something odd happen.

I have a series of chunks through time with markers for position between them.

2 camera groups for each chunk both starting with a precalibration values from an earlier good model with the same camera (but different working distance), one with a fixed focus, the other variable focus (not enough room to stick to the focus)

when i first ran everything it seemed ok, but at some point i found a lot of "nan" in my markers.  I eventually tracked this down to my variable calibration group parameters all estimated to 0.

I'm not sure when this happened as it all looked like it worked first time.
Is there something that's likely to lead to this situation (having adaptive camera fitting on, or off during alignment for example)

Thanks

Alexey Pasumansky

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #1 on: December 28, 2021, 02:29:17 PM »
Hello hairyfreak,

Can you please share the project with the alignment results (aligned cameras, tie points and markers) to support@agisoft.com? Would be helpful, if the project contains the chunks prior and after the optimization (if "nan" values appear only after optimization).
Best regards,
Alexey Pasumansky,
Agisoft LLC

hairyfreak

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #2 on: December 29, 2021, 01:44:35 AM »
Hi,

I'm afraid i've fixed the issue by resetting alignment then re-running workflow-align photos (without reset alignment).

I can still send the project if you think it might have something diagnositic in it?

Thanks

Alexey Pasumansky

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #3 on: December 29, 2021, 10:29:43 AM »
Hello hairyfreak,

Yes, you can still send the problematic project to support@agisoft.com.
Best regards,
Alexey Pasumansky,
Agisoft LLC

hairyfreak

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #4 on: December 29, 2021, 11:25:17 AM »
Thanks, will do.

Just found the problem reappear too. Don't think I've done anything other than build mesh and texture, close the file and open (run on batch) after correcting the problem, so very odd that it's come back.


Alexey Pasumansky

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #5 on: December 29, 2021, 05:50:16 PM »
Hello hairyfreak,

I'm not sure, how it happened that all calibration coefficients (including F) have turned to be zeros, when Image Variant options have been selected, but you can try to do the following:
- uncheck all image variant parameters,
- close Camera Calibration dialog with OK button,
- open the dialog again and select Image Variant parameters for the required calibration group.
After that optimize the camera alignment, if required.
Best regards,
Alexey Pasumansky,
Agisoft LLC

hairyfreak

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #6 on: December 29, 2021, 08:57:15 PM »
Thanks

I did
1. open camera calibraiton (all values are 0)
2. turn of image variant paramters
3. closed camera calibration
4. open camera calibration - it had numbers but after date time it had Cx, Cy. and all have the same numbers
5. close camera calibraiton with ok
6. set optomize cameras and set into the queue....

then metashape crashed on a different project. - before optomize was run (i think)

so I opened the file again (unopotomized i think), and do 1.  - now after date and time it does has F. and all the numbers are different (not 0)
then I repeat 2 - 4. Same Cx, Cy straight after date time.
then i closed the calibration and opened again, this time I have the same, but if I do it with the other camera group I get the F column too.


Thanks

« Last Edit: December 29, 2021, 08:59:22 PM by hairyfreak »

hairyfreak

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #7 on: December 29, 2021, 09:51:20 PM »
In the parent project I first noticed this I'm having similar issues, but instead of the columns starting at cx, I don't have any columns after date time.

Hope this helps point out what it/ or I is getting wrong.

Thanks again.

Alexey Pasumansky

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #8 on: December 30, 2021, 12:15:05 AM »
Hello hairyfreak,

Do you mean that F value is zero when you just add the images to the new project?
Best regards,
Alexey Pasumansky,
Agisoft LLC

hairyfreak

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Re: "nan" markers and 0 paramaters with image variant calibraiton
« Reply #9 on: December 30, 2021, 01:11:54 AM »
Hi Alexey,

No. This is all with projects that have already aligned successfully (with the image-varient options selected during alignment).

But on reopening the project (s, i'm finding it in any project i've tried the image variant option) the F has 0 when I come back to it.


When I turn off the image-variant option following your instructions, the F and other columns disappear - as expected.

When I turn them back on, either there is no F column, only cy, cx, k etc..  or no extra columns at all.
but the project will work still work (non 'nan' values).

Other times if I turn image-variant options back-on, or on for the first time for a calibration group, it will have all the columns and all the values will be the same as each other before i optomize.


It feels quite confusing.  Hope you can understand.