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Author Topic: GCP problem  (Read 1919 times)

Alterco

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GCP problem
« on: May 09, 2019, 04:17:51 PM »

Hi,

I am currently using the Metashape version 1.5.2 build 7838 (64bits).

Working on placing GCP on photos after alignment, dense cloud and meshing done.

It works well until a point where the pix error become huge (>100) and the referenced points are placed at wrong places.

I have to restart the software and open the project I was working on to continue the referencing.

The previous wrong points are still wrong but I can creat new points that are good.

The same chunks with faulse points can be referenced with no porblem until the problem appaer aggain (arround 10 gcp placed)...

For exemple (file attached) the same gcp marked during the problem and after a restart.

Regards,

AA





Alexey Pasumansky

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Re: GCP problem
« Reply #1 on: May 10, 2019, 01:33:41 PM »
Hello Alterco,

Large Error in pixels usually means that either one of the projections has been placed incorrectly, or at lest one of the cameras where the marker projection is placed has been aligned incorrectly.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Alterco

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Re: GCP problem
« Reply #2 on: May 10, 2019, 02:17:01 PM »

Thank you for your answer.


But I do not understand why on the same chunk :
- Add a marker on a photo 01
- Check the place of the marker on the next photo : the marker is not at the right place
- Check the marker on the mesh : the marker is not at the right place
- save
- close the software
- open the software
- load the project
- Add a new marker at the excat same place on the same photo 01
- Check the place of the marker on the next photo : the marker is at the right place
- Check the marker on the mesh : the marker is at the right place

It is the same chunk, same photo, same place, why the result change and why it is good after just a reboot of the soft ?


Best regards,

AA


Alterco

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Re: GCP problem
« Reply #3 on: May 23, 2019, 10:25:40 AM »
Hi,

After a series of new chunks processed, I can confirm that there is problem.

Working on placing GCP on processed mesh.
After a period of time placing points, new points created start to have a huge error.
Just need a restart of the software to continue placing the points at the same places without error...

I found a solution to my problem (restart the software) but I think it is not a clean solution...

AA