Reasonable box_size for Background2D?

The 2D Background and Noise Estimation states that:

Background2D requires the size of the box (box_size) in which to estimate the background. Selecting the box size requires some care by the user. The box size should generally be larger than the typical size of sources in the image, but small enough to encapsulate any background variations.

All other parameters have some reasonable default values that can be used, but not box_size.

Is there a reasonable rule of thumb for selecting this value? I’ve found that (for some frames I’m processing) a value of ~7xFWHM produces reasonably cleaned images. Smaller values produce a noisy cleaned image (data - bckg) and larger values show no improvements.

Is this a reasonable rule or it’s this the case for my images only? Can a reasonable general rule even be stated? If so, could it be added to the docs.

[larrybradley]

Thanks, @Gabriel-p. I tried to be descriptive as possible for recommended values, but I think this is one parameter that does require some trial and error on the part of the user for their particular scene.

[larrybradley]

Yes, for that particular case one could probably define a reasonable box size. Without doing a lot of tests, I’m not sure what that size is though. Is that your case where 7 * FWHM gave good results? If there is a good box size recommendation for that particular case, I’d be happy to include it in the docs.