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Author Topic: Photogrammetry with thermal images / water  (Read 676 times)

KarenStr

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Photogrammetry with thermal images / water
« on: December 01, 2021, 05:41:34 PM »
Hello,

I have a question regarding photogrammetry using thermal images of a small river bed. While Metashape is (understandably) not able to align the water-parts of the images, it can align features of the riverside.

In a few test images, we were able to get a point could based on one riverside. In the rendered model, it also shows colours for the water part. Since there were no tie points detected in that, I assume the colour is some sort of interpolation.  Can someone tell me if those results could be of any use (with regards to tracking temperature differences of the water surface)? How does the interpolation happen?

If we took good care that each photo contains part of the riverside on both sides of the photos, would that possibly give us a model of the water in between as well?

Best regards
Karen

SimonBrown

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Re: Photogrammetry with thermal images / water
« Reply #1 on: December 03, 2021, 12:11:24 PM »
The banks of the river - all things being equal - will be point-rich and align.

Are you using a drone? If the width of the river is not too great then a flight at altitude where both banks are visible might align to make a single model.

There is a risk with this as tie points may become clustered...not good.

The river itself? This will be interpolated, where the mesh grows its boundaries until either it a) meets another piece of mesh, or b) the bounding box or c) the algorithm calls a halt.

So the data in the river would be made up...but...it might be possible to extract data from the aligned images. We are doing this with some data embedded in the jpeg (actually in the image...as pixels...) and pulling it into machine readable format...

But without seeing the source data and understanding what the outputs are the above may be relevant...or not. Can you share anything?
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