From: "Perry E. Metzger" <perry@piermont.com>
Date: Thu, 25 Jul 1996 15:44:17 +0800
To: mpd@netcom.com (Mike Duvos)
Subject: Re: Digital Watermarks for copy protection in recent Billbo
In-Reply-To: <199607250438.VAA02125@netcom6.netcom.com>
Message-ID: <199607250525.BAA19198@jekyll.piermont.com>
MIME-Version: 1.0
Content-Type: text/plain



Mike Duvos writes:
> "Perry E. Metzger" <perry@piermont.com> writes:
>  > The Nyquist Theorem states you need exactly twice the
>  > samples, not over twice. The magic number isn't something
>  > like 2.2, its exactly 2.
> 
> The Sampling Theorem states that equally spaced instantaneous
> samples must be taken at a rate GREATER THAN twice the highest
> frequency present in the analog signal being sampled.

That is just about what I said. The point is that the magic number
isn't 2.2 or anything similar -- the breakpoint is exactly twice the
frequency.

> Although anything over twice the highest frequency will work in a
> theoretical sense, a small fudge factor does wonders for digital
> signal processing,

I believe I mentioned the need for that, too.

Perry