Georeference single image of an orthomap

Hello everybody,
I’m using WebODM in order to do some anomaly detection on a solar plant. I have done the orthomap starting from 484 drone thermal images, such that I can derive a map of the entire plant. Then I want to map each point of the single single images into the orthomap (so I can derive their latitude and longitude), but I don’t know how to do it given that I have only the coordinates of the drone while it was shooting that picture but they are not so accurate as I need. Does anyone know how to solve it?

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I use Exiftool to extract the image GPS coordinates in bulk to a CSV then open the ortho & CSV in Google Earth Pro to see the camera positions overlaid onto the ortho.

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Not a solution, but see this thread for additional discussion on georeferencing images.
And if you do find a solution, please post it!

Cheers

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In QGis you can geo reference images of any kind.

Maybe worth a try.

Up to now my idea is to modify the file orthorectify.py adding this line
image
expecting that such point will represent the pixel coordinates in the dsm of the image center.

starting from such point I can rescale each original image such that each element of the original image will have the same length (in pixel) with respect to the orthomap. Then map each point of the given image as the center point (in the orthomap) + the displacement of that point from the center

Using webODM the result of the entire process returns an orthomap which has the double of the size of the dsm, so it is easy to map points from the dsm to the orthomap.

Unfortunately using ODM (and of course also orthorectify.py uses this data) returns 3 orthomaps and one dsm (blank as if viewed through numpy or the standard windows image viewer) with totally different shapes and the result is of course totally messed.
Following the shapes of the results

Could you tell me where I am doing wrong in my reasoning?
Did you know which data I have to rely on?

Update, I solved in another way, I have posted my solution in a notebook on my github. Unfortunately I had to exclude outputs, but you can try with your own data.
The link is the following
odm_orthorectifictaion_addon/orthorectification_no_output.ipynb at main · francescoromito/odm_orthorectifictaion_addon (github.com)

Hoping this can help someone :smiley:

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