Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!ucbvax!norton!crounse
From: crounse@norton.uucp (Great Rumpuscat)
Newsgroups: comp.dsp
Subject: 2-D FIR design question
Summary: would like near circular symmetry in frequency domain.
Message-ID: <41644@ucbvax.BERKELEY.EDU>
Date: 9 Apr 91 00:27:06 GMT
Sender: nobody@ucbvax.BERKELEY.EDU
Reply-To: crounse@norton.berkeley.edu
Lines: 15


	I am working on a problem in image halftoning which requires
a 2-D FIR filter which has a near circular-symmetric frequency response.
That is, its 2-D DTFT should depend only on the radial frequency.  I am
fairly convinced that this cannot be done with a finite impulse 
response.  Does anyone know of any references concerning how close 
(by some measure) one can get?         

Thanks,
ken.
,,,,,,,,,,,,,,,,,crounse@norton.berkeley.edu,,,,,,,,,,,,,,,,,,,,,,,
Kenneth R. Crounse,      -  UC Berkeley
King of                  -  (Rally Behind the Ridiculous)
Randomness and           -  Dept. of EECS
Chaos                    -  Nonlinear Electronics Laboratory