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Author Topic: Iphone collected geotag dense point cloud is coming inverted  (Read 212 times)

ppant

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Iphone collected geotag dense point cloud is coming inverted
« on: September 21, 2022, 10:18:25 PM »
Hey I have a issue. I am collected couple of 360 geo tag image from iPhone and the mosaic result is sometime coming inverted. But something its coming upright.  not sure  what is causing those.

Thanks

Ppant

ppant

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Re: Iphone collected geotag dense point cloud is coming inverted
« Reply #1 on: September 21, 2022, 10:33:35 PM »
Could any one explain why the point cloud is inverted.

ppant

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Re: Iphone collected geotag dense point cloud is coming inverted
« Reply #2 on: September 21, 2022, 10:37:45 PM »
Based on this post  https://www.agisoft.com/forum/index.php?topic=3702.0
I also add the camera center position cx, cy and in the image exif XMP but not sure why result is stull inverted

Alexey Pasumansky

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Re: Iphone collected geotag dense point cloud is coming inverted
« Reply #3 on: September 22, 2022, 01:42:14 PM »
Hello Ppant,

If you are loading coordinates of the camera locations to the Reference pane, how accurately they are measured?

I am not sure, if you can accurately georeference small project (< 1 m size), when the coordinates of the camera location are measure with 10 m accuracy.
Best regards,
Alexey Pasumansky,
Agisoft LLC

ppant

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Re: Iphone collected geotag dense point cloud is coming inverted
« Reply #4 on: September 23, 2022, 05:08:03 AM »
Alexey
Thanks for the update. I am using the phone arkit to estimate the geo-position. But your comment leads me to the next question. If my position is not accurate How to know automatically Mosiac model dense point cloud is inverted? and how to fix the dense point cloud? I am running a script to generate the dense point cloud.  From the script is there a way to fix it. Looking forward to hearing from you


Thanks
Ppant

Alexey Pasumansky

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Re: Iphone collected geotag dense point cloud is coming inverted
« Reply #5 on: September 26, 2022, 08:39:28 PM »
Hello Ppant,

You can define the coordinate system (i.e. scale and orientation) by placing a few coded targets around the object of interest and having their coordinates input to the Reference pane.

For example, print 4-8 targets on the single A2 or A3 sheet, so that you could easily measure their coordinates, assuming that one of the targets has (0, 0, 0) coordinate. Then put this sheet under the object of interest before taking images. After all the images are collected you can run Detect Markers command, input the coordinates of the detecte markers (or load from the text tile) and apply this information to perform the model referencing.

I recommend to use anything that could help to scale the model properly (at least a pair of markers with known distance between them). In such case you would need to apply the model orientation either manually (using Rotate Object instrument) or with custom script that will do that automatically after manually placing three markers (even in model view) on the flat surface.
If you are planning to follow the latter approach, I can assist you with such script.

Note that in any case it is recommended to uncheck all cameras in the Reference pane and switch the coordinate system to Local Coordinates for the chunk, as in the small scales geotagged images are not helpful.
Best regards,
Alexey Pasumansky,
Agisoft LLC