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Author Topic: Do you recommend removing Tie points outside of the desired region?  (Read 1705 times)

swenninger

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Hi everyone,

we are using Agisoft Metashape for reconstructing pointclouds of human bodies with a moving camera. The bounding region of the human is computed dynamically  based on estimated camera locations.

We split all images into seperate camera groups and optimize camera parameters afterwards. This helped the dense pointcloud reconstruction.

We were wondering if the dense pointcloud reconstruction would additionally benefit from removing all tie points outside the region of interest and then optimizing camera parameters again. Do you have any recommendations for this?

Best regards
Stephan

Alexey Pasumansky

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Re: Do you recommend removing Tie points outside of the desired region?
« Reply #1 on: February 11, 2020, 09:29:48 PM »
Hello Stephan,

The tie points allows to select the image pairs that will be used for the depth maps calculation. If the number of the common tie points (inside the bounding box) is less than the certain threshold, then such pair will not be used for the depth maps calculation.

So if you have some points outside the bounding box - removing them after optimization wouldn't have any effect on the dense cloud. But if you remove the points which are obvious outliers or those that have very high reprojection error and then optimize the alignment, then it could improve the alignment accuracy. However, removing too many points may affect the further depth maps reconstruction, if there are too few points left in the box.
Best regards,
Alexey Pasumansky,
AgiSoft LLC