Edge-Preserving Smoothing

Edge-Preserving Smoothing is a simple 3X3 bilateral filtering.

The basic idea underlying bilateral filtering is to do in the range of image what traditional filters do in their domain. Two pixels can be close to each other,occupying nearby spatial location, or they can be similar to each other,having nearby values, possibly in a perceptually meaningful fashion. You can specify distance of the closest pixels in color and space domains via corresponding sliders.

To use the Edge-Preserving Smoothing filter:

Choose Image > Restoration > Edge-Preserving Smoothing