``Lowpass'' - lowpass filter

VFX name:

iLowpass

IMPROMPTU Equivalent:

Lowpass

purpose:

Apply a lowpass filter to an input volume.

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
option = hamming
iterations = 1

Two options are possible: the Hamming window [22] and a simple window average.

comments:

1.

The Hamming window is a true lowpass filter. The simple window average, often touted as a lowpass filter, is not, since its frequency response goes as sin(x)/x (large sidelobes in the frequency domain!) [4]. Thus, I recommend using the Hamming window.

2.

For a well-defined Hamming-window operator, use at least a dimension=5 operator.

3.

Moderate computation time required.