``Symmetric_Nearest_Neighbor'' - symmetric nearest-neighbor mean filter

VFX name:

iSymmetricNN

IMPROMPTU Equivalent:

Symmetric_Nearest_Neighbor

purpose:

Run the symmetric nearest-neighbor (SNN) mean filter on an input volume [6]. The SNN mean filter is a nonlinear, noise-smoothing, edge-preserving filter. It also can preserve thin lines (depending on the operator window size) in images (although the sigma filter may be better for this purpose).

input:

An 8-bit volume.

output:

An 8-bit volume.

parameters:

Default parameters menu is

x_filter_dimension = 3
y_filter_dimension = 3
z_filter_dimension = 3
iterations = 1

The parameters ``x_filter_dimension'', etc., specify the size of the local operator used by the filter.

comments:

1.

This filter may ``sharpen'' regions more impressively than the sigma filter, but the sigma filter will preserve thin lines better. The maximum-homogeneity filter sharpens noise and reduces noise better than both the SNN and sigma filters.

2.

This is a moderate computation algorithm (depending on the window size).