Get points cloud with actual GPS

[cst2825023]

Hello,
I have some images taken from a drone with known GPS positions. I'd like to use those positions within Hybid-Sfm to get points cloud with actual GPS, but I don't know where to start. Would it be possible to provide camera GPS positions to the application build_reconstruction?
Any help on this would be very grateful. Many thanks for this useful library!

[sweeneychris]

If GPS is in the exif metadata then Theia will pick it up automatically, and there are some tools you can use to convert to ECEF and align the reconstructions to those coordinates (but it isn't automatically done in the pipelines)

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On Wed, Jun 12, 2019, 8:44 PM cst2825023 ***@***.***> wrote: Hello, I have some images taken from a drone with known GPS positions. I'd like to use those positions within Hybid-Sfm to get points cloud with actual GPS, but I don't know where to start. Would it be possible to provide camera GPS positions to the application build_reconstruction? Any help on this would be very grateful. Many thanks for this useful library! — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#242?email_source=notifications&email_token=AAGDFNRDO2LTVKBRPYLML7DP2G7BZA5CNFSM4HXVUMOKYY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4GZGWMZQ>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAGDFNVBYOZWBMA3SXXV62LP2G7BZANCNFSM4HXVUMOA> .

[cst2825023]

Thank you for your reply. I have a few questions below. Firstly, I have input images with GPS information in the metadata, and converted to ECEF. But the points cloud position generated by Hybid-Sfm are random. I want to know if I need to convert reconstruction points to actual coordinate system using actual camera position by myself or modify part codes in sfm to combine points with actual GPS.

[sweeneychris]

But the points cloud position generated by Hybid-Sfm are random

Just to clarify, they are not *random* but are in an arbitrary coordinate system. Yes, you will need to apply the transform from the arbitrary coordinate system to the GPS/ECEF aligned one

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On Thu, Jun 13, 2019 at 6:57 PM cst2825023 ***@***.***> wrote: Thank you for your reply. I have a few questions below. Firstly, I have input images with GPS information in the metadata, and converted to ECEF. But the points cloud position generated by Hybid-Sfm are random. I want to know if I need to convert reconstruction points to actual coordinate system using actual camera position by myself or modify part codes in sfm to combine points with actual GPS. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#242?email_source=notifications&email_token=AAGDFNUV2UNCDZB2ZDVHJA3P2L3HTA5CNFSM4HXVUMOKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGODXVPY6Q#issuecomment-501939322>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAGDFNWOFCYKRPWT36QGXYLP2L3HTANCNFSM4HXVUMOA> .

[Aleksei91]

Can I modify bundle adjustment somehow to use prior information about camera position, so result of reconstruction/pose estimation whould not differ much? Now I sometimes get dramaticaly wrong reconstruction results (camera positions almost random), maybe I can improve it with this info or it's useless and my photos just too hard for feature matching?