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From: hanke@nessie.cs.id.ethz.ch (Norbert Hanke)
Newsgroups: comp.dsp
Subject: Re: Digital Filter Design Software
Keywords: DSP, FIR, Filter Design
Message-ID: <1991Mar28.114331.8849@bernina.ethz.ch>
Date: 28 Mar 91 11:43:31 GMT
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In article <2345@gonzales.munsell.UUCP> ada@munsell.UUCP (Andy Adams) writes:
>
>        I am trying to design fairly large (16->32 tap) FIR
>        filters for image sharpness correction/enhancement. Ideally,
>        I would like to be able to specify filter gains at various
>        frequencies and have the program optimally design the coeffs.
>        The band-edge, band-gain, band-ripple approach of CARL
>        seems to be very awkward and unpredictable for this 
>        type of filter design. 

Try to use them Remez Exchange Algorithm, if you want to design linear
phase filters.

Internally, Remez builds a large grid of the specified frequencies, each
point having its desired value and the weight. It should be possible to
adapt Remez in a way to allow for arbitrary frequency responses, not just
the band-edge, band-gain, band-weight approach.

Norbert Hanke
Power Electronics &
Electrometrology
ETH Zurich, Switzerland