WEB: GENERAL FILTER
General Filter
This operation interactively creates a mask based on a power spectrum
which can be used for Fourier filtering. The operation solicits name
of a power spectrum image which is displayed. It also solicits name of
the output file which is in Fourier format. Using the mouse, user can
create a mask on the power spectum space. Mask consists of circular
Gaussians with values from 0...1.0. Up to 200 circles are
allowed on each mask. The Gaussian circle sizes can be set with
the initial menu and altered with the up-arrow and down-arrow keys
while drawing masks. The final mask is saved to the
output file only when the center mouse button is pushed to terminate
the masking.
This operation replaces the old SPIDER 'GF operation for
quasi-optical Fourier Filtration . It can be used to
masks out Fourier coefficients from the input file in the
vicinity of specified reflections, and transfers these coefficients
into the output Fourier filter file. This filter file can then
be multipled by a Fourier file for filtering.
Last update: 10/4/1998
ArDean Leith