Remove floaters about opensplat

[pfxuan]

This method can give some help. But it’s a little computation heavy.

[pierotofy]

Interesting, it's similar to this one from PDAL: https://pdal.io/en/2.7.0/stages/filters.outlier.html#statistical-method (which can be made to run fast).

[pfxuan]

Good idea. Open3D also has a few similar built-in functions: https://www.open3d.org/docs/latest/tutorial/Advanced/pointcloud_outlier_removal.html

[pierotofy]

I've tried to implement this method in https://github.com/pierotofy/OpenSplat/tree/filter, but although there's some reduction of noise, there's also an increase in other parts (at least in the train dataset) near the object of interest. The validation loss also seems to increase.

[pfxuan]

Perhaps removing floaters could be considered as a post-processing step after the 3DGS model gets fully trained. Additionally, I found enhancing the training code, improving camera pose, and removing blurry image could substantially minimize floating artifacts.