DenseRLOF breaks if the sprite image is too small

[Bauxitedev]

It will gobble up RAM until it crashes. This is an issue in opencv-rust so there is not much to do about this, except maybe adding a minimum sprite size.

[maxtron95]

Can confirm, The program runs into memory errors at 32x32px, but an image size of 710x400px seems to work fine from what I tested.

I would probably suggest preventing DenseRLOF from being selected when under a certain sprite size.