4.7. Symmetric Nearest Neighbor

图 17.46. Example for the “Symmetric Nearest Neighbor” filter

Left: original image. Right: filter applied.

This filter blurs the image preserving edges. It is very effective in noise reduction maintaining sharp edges.

It works comparing each pixel to its neighboring pixels and to 1 or 2 pairs of symmetric pixels around the center.

4 symmetric pairs

This filter is found in the main menu under Filters → Enhance → Symmetric Nearest Neighbor….

图 17.47. “Symmetric Nearest neighbor” filter options

Presets, “Input Type”, Clipping, Blending Options, Preview, Merge filter, Split view

	注意
	These options are described in 第 2 节 “Common Features”.

Radius

Radius, in pixels, of square pixel region. Width and height of this region are radius*2+1:

Pairs

You can select 1 or 2 pairs: higher number preserves more acute features.