Smart Blur effect
The
Smart Blur effect blurs an image while preserving lines and edges
within the image. For example, you can use the Smart Blur effect
to smoothly blur shaded areas while retaining crisp outlines of
text and vector graphics.

Original (left), and with effect applied (right)
This effect works with 8-bpc and 16-bpc color.
- Radius
- How far the filter searches for dissimilar pixels to blur.
- Threshold
- How different the values of pixels should be before they
are eliminated.
- Mode
- What parts of the image receive the blur. Normal specifies
that the blur be applied to the entire selection, whereas Edge Only
and Overlay Edge specify that the blur be applied only to the edges
of color transitions. Where significant contrast occurs, Edge Only
applies black-and-white edges, and Overlay Edge applies white.