The `sample_disk` returns samples inside a disk of radius 1
which was spanning 2 pixels. The blackmann-haris filter has
not much energy at the edge of the filter and since we
don't importance sample the filter, we have very low weight
samples at some time steps. Improve this by biasing the
distribution towards the center.
This is a temporary solution until we have proper importance
sample of the filtering function for this case.
Fix#123630
8718aa5513