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creating a 2D mask for image filtering [message #77215]

Wed, 17 August 2011 03:47

David Higgins
Messages: 13
Registered: August 2009

Junior Member

Hi all

I need to create a 2D mask to filter data in the frequency domain
(apodization). I would like to leave 0.8 of the centre-to-edge of the
data untouched (i.e. a circle of untouched data), and then a Hanning-
type shape to smooth down to zero at the edges. (Think of an upside-
down frying pan, kinda.) I can apply a Hanning filter with

apod_fn = HANNING(kx_res, ky_res, alpha=0.5)

but of course the centre area which I would like to have untouched
doesn't exist, and the filter is too aggressive. I'd go without the
Hanning shape requirement if I could get more-or-less the right shape.
I see also DIGITAL_FILTER, but can't seem to widen the filter with my
changes to it's arguments.

Thanks for any pointers.

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[Message index]

		creating a 2D mask for image filtering By: David Higgins on Wed, 17 August 2011 03:47
		Re: creating a 2D mask for image filtering By: David Higgins on Thu, 18 August 2011 07:50
		Re: creating a 2D mask for image filtering By: orifox2003 on Wed, 20 February 2013 11:26
		Re: creating a 2D mask for image filtering By: David Fanning on Thu, 18 August 2011 07:37
		Re: creating a 2D mask for image filtering By: David Higgins on Thu, 18 August 2011 07:28
		Re: creating a 2D mask for image filtering By: David Fanning on Wed, 17 August 2011 10:44
		Re: creating a 2D mask for image filtering By: orifox2003 on Wed, 20 February 2013 11:30

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