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Author Topic: Same location UAV images aligned flipped ?  (Read 212 times)

jolu123

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Same location UAV images aligned flipped ?
« on: January 22, 2019, 08:12:09 AM »
When doing 2 UAV captures at diffrent heights agisoft wont align cameras.

The 2 diffrent images series alignes flipped as if diffrent objects.

The images are off the same area but was captured 30 min appart. Same lighting conditions but seem geo referenced data is mirrored or offset somehow.

Any clues what could be wrong and how to make align as one series of images ?

 :'(


Alexey Pasumansky

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Re: Same location UAV images aligned flipped ?
« Reply #1 on: January 23, 2019, 06:02:02 PM »
Hello jolu123,

Can you send the project in PSZ format (use it via Save As dialog) to support@agisoft.com with the alignment results where you are observing these issues?
Best regards,
Alexey Pasumansky,
AgiSoft LLC

jolu123

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Re: Same location UAV images aligned flipped ?
« Reply #2 on: January 28, 2019, 08:18:36 AM »
Hi , thanks for the reply.

Ok , would it be fine without the images due to size ?

I’ve been doing some more testing with trying to align UAV flights .

The gps info provided for each flight provide the basic layout, but
when aligned together they won’t  line up.

Align them sep work fine , but then align chunks to combine them in the end but
will result in 2 layers pointcloud in different areas of the scan.

Realign all with no reference and reset makes many different weird parts in space.

Do you have any understanding how this could happend?

There is plenty of overlap on the images.

One set is nadir and one set is nadir +30 on the same area.

It is as it’s not trying to align the images visually anymore and the gps info override it in a faulty way.

From no additional info I would expect it to do a regular alignment.

Await your reply how to proceed

/J

Alexey Pasumansky

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Re: Same location UAV images aligned flipped ?
« Reply #3 on: January 28, 2019, 10:48:00 AM »
Hello jolu123,

At the first time it would be sufficient to have only project with the alignment results (tie points cloud and aligned cameras).
Best regards,
Alexey Pasumansky,
AgiSoft LLC

jolu123

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Re: Same location UAV images aligned flipped ?
« Reply #4 on: January 31, 2019, 12:05:14 PM »
email with provided project and info is sent >D

Alexey Pasumansky

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Re: Same location UAV images aligned flipped ?
« Reply #5 on: January 31, 2019, 12:40:53 PM »
Hello jolu123,

In the project I see that the altitude data loaded for the cameras to the Refernece pane is about 100.000 km below ellipsoid.

Looks like the altitude is missing in the EXIF data.

You can use the following script to load the altitude from the XMP meta information (RelativeAltitude value):
https://github.com/agisoft-llc/metashape-scripts/blob/master/src/read_altitude_from_DJI_meta.py
Best regards,
Alexey Pasumansky,
AgiSoft LLC

jolu123

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Re: Same location UAV images aligned flipped ?
« Reply #6 on: January 31, 2019, 02:43:26 PM »
Hi , Thanks for looking into this.

Where do I see this information  ? Just so I can confirm other photo sets .

Also can I confirm this by looking at the raw dng files ?

To understand , the alltitude information from the DJI Mavic 2 is then not provided in the images ?

Does the script need anything else than access to the original image files ?
https://forum.dji.com/thread-171969-1-1.html?page=2
Sorry for all the questions but really need to understand how to sort this out for my project.

Would it be helpful if I provide you with a sample raw image from the flight ?

If it could be any faulty format provided by DJI ?

Johan

I found this topic and seem to be issues from DJI firmware!

https://forum.dji.com/thread-171969-1-1.html?page=2

Does the provided script help sort theese issues ?

Its only important to get the alignment correct , even if height doesnt match realworld height.
« Last Edit: January 31, 2019, 03:03:04 PM by jolu123 »