About the mask update process

[SvyJ]

How are the "background_length=33" and "target_length=3" determined during the mask update process?

[XinyiYing]

"background_length" represents the region (background_lengthbackground_length) for label update of each target with a given point label, and is empirically set to 33. Depend on the dataset, you have to make sure that given a point label, a mask of size background_lengthbackground_length can cover the target.
"target_length" are used to eliminate local background clutter. This is, the candidate pixels, which have no intersection with the "target_length*target_length" region of the given point label, are deleted. To ensure precision, we set "target_length" as a small number of 3.