[phenixbb] Spatial filtering

Potentially silly question: is spatial filtering used for increasing contrast in electron density maps? Is it used for any other kind of data manipulation in macromolecular crystallography, e.g., diffraction data processing, density modification, etc. I'm a bit fuzzy on that subject, and so I said 'potentially silly', because it could be that such approaches are totally common but have different names (such as local averaging/scaling and so on). Many thanks in advance. Cheers, MM