Checkpoints error

serveur_calcul · June 6, 2024, 5:51pm

Hi,

Has anyone been having trouble processing using checkpoints lately?

For some reason, when processing images along with checkpoints, it always results in meters off. It’s been doing it for a few versions of Pix4dmatic now. I know because I tried it on earlier versions and there’s no issue.

anastasis.spachos · June 11, 2024, 1:25pm

Hello,

My name is Spachos from the Technical Support. Thank you for bringing up this subject.

Can you please share with us from which version you have noticed this issue with the checkpoints?
It would also be very useful to tell us a version of PIX4Dmatic that you remember you had no issue with, so we can narrow down the issue as much as possible.

Best regards,

serveur_calcul · June 11, 2024, 2:17pm

Hello Spachos

I am currently on the latest stable version (1.58.2).

The computer on which it does not have that issue has the 1.43.2 version.

Thank you for your help

anastasis.spachos · June 12, 2024, 9:13am

Hello again,

Thank you for the information,

Can you please share with me 1 or 2 Quality Reports of projects that have the checkpoints issues?

Best regards,
Spachos

serveur_calcul · June 12, 2024, 11:25am

Of course. Here are two projects, both having the issue discussed and the second one I also included the properly processed checkpoints on version 1.43 (Project 2-B).

You can view them here : Pix4D projects

serveur_calcul · June 21, 2024, 1:55pm

Hello Spachos,

Have you had time to look into it ?

anastasis.spachos · July 25, 2024, 9:40am

Hello,

Thank you for sharing the Quality Reports with me. My apologies for the extended reply time.

I can clearly see the differences. In the last few days, I tested internally with different projects. I have noticed differences in the error for the Checkpoints but not as large as the ones you shared with us. Here is what I did:

Add images
Add GCPs (Select the correct CRS for GCPs)
Mark GCPs
Run Calibration
After Calibration is successful, I changed the Tie points from GCPs to Checkpoints
Run Reoptimization.
The Checkpoints have similar (but larger errors) as previously.

Please note that I am using the 1.64.0 version of PIX4Dmatic. Here are 2 Quality Reports for comparison: OneDrive

That being said, I have forwarded this to the product team for further investigation. Thank you for bringing this to our attention.

I am at your disposal if you need further help or have any questions.
Best regards,
Anastasis Spachos

anastasis.spachos · July 25, 2024, 12:18pm

Hello,

Can you please share with me the exact steps that you performed that result in these large errors?

Please also note that in a recent release, we changed the default from EGM96 to ellipsoidal height when this is not specified in the image metadata so maybe this explains the difference.

Can you please check the Image CRS and make sure to use the ellipsoidal before running the Calibration?

I am looking forward to hearing back from you.
Best regards

serveur_calcul · August 12, 2024, 6:23pm

Hello,

Thank you for the follow-up.

The error seems to be fixed since the last Pix4dMatic update, so I’m thinking it’s what you said about the default height system. I no longer have issues with using checkpoints with my local Geoid!

My usual workflow is as follows:

Import images
Import GCPs (select corresponding Horizontal & vertical datum)
Mark them and switch from GCP to Checkpoints
Run Calibration and verify Quality report
Run other needed steps…

anastasis.spachos · August 13, 2024, 2:19pm

Hello,

Thank you for the update. I am glad that your issue is now solved.

Best regards,
Spachos Anastasis