``Average_Minimum'' - average/minimum filter

VFX name:

iAverageMin

IMPROMPTU Equivalent:

Average_Min

purpose:

This filter first applies a window average and then a local minimum operation to an input volume. It reduces noise and makes a volume easier to segment. Use this filter when the regions of interest are dim (the filter favors dim regions). Also, see the function ``ave_max''.

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 window average and local minimum operations use the same operator size.

comments:

1.

The filter is similar to a lowpass filter, yet the minimum operation makes it nonlinear. Use it to bring out dim regions.

2.

You can do a better version of this function by first doing a hamming lowpass filter (``lowpass'' in the ``enhance'' category) and then running a local minimum (``min'' in the ``morphology'' category).

3.

Moderate computation required.