Me:
You know, Jan, you could have disagreed with me without this horseshit
comment:
Jan:
> Thanks, George -- I knew I could count on you to have the
> definitive word on just about anything.
Me:
Yeah, right. I'm the one on this list who thinks of himself as "Mr
Know-it-all". But, in truth, Jan, you're not the only schmuck who's ever
dragged himself thru engineering school. There are others on this list
who've been there, done that. And some even appear to know a wee bit more
than you about a few things. I'm not claiming I do, heaven forbid.
Jan:
">But I guess you can believe anything you read on a website."
Me:
Perhaps you should look at the website I cited. I'd say it's fairly
credible. I'd cite an engineering text too, but you'd just say you know more
than the author, so I won't bother. Here's another quote though from the
website, copied here so you won't have to lift a finger:
Engineering text:
***
"The sampling theorem states that for a limited bandwidth (band-limited)
signal with maximum frequency fmax, the equally spaced sampling frequency fs
must be GREATER THAN twice the maximum frequency fmax, i.e.,
fs > 2.fmax
in order to have the signal be uniquely reconstructed WITHOUT ALIASING.
The FREQUENCY 2.fmax is called the Nyquist sampling RATE. Half of this
value, fmax, is sometimes called the Nyquist frequency. "
***
Jan:
"> You guys are all confusing "rate" with "frequency.""
Me:
Notice how the author of this definition also confuses the terms 'Frequency'
and 'rate'. I don't want to confuse your steel trap of a mind, but that's
because THEY ARE THE SAME THING.
Frequency: cycles per second
Rate: samples per second.
Jan:
> It's easier to comprehend in 1-dimensional space than 2D.
> Consider a very bad CD recorder/player that samples audio
> frequencies at a 10,000 Hz rate. If you feed the recorder an
> audio frequency of 6,200 Hz, the player will produce equal
> amplitude frequencies of 3,800 and 1,200 Hz -- not at all what
> was intended, and pretty awful sounding.
>
> This is what so-called "grain aliasing" is all about: scanning at
> a frequency that is near the RMS grain frequency of the image.
> Whereas if one scanned at a much lower frequency, it would
> accurately reproduce whatever it picked up, without ugly
> non-harmonic components.
Me:
I hope everyone who has read this far will look carefully at Jan's last
sentence above. Let's take his statement to it's limit: Why, it would
recommend taking ONE SAMPLE PER SECOND!!. Here's his statement again:
> Whereas if one scanned at a much LOWER frequency, it would
> accurately reproduce whatever it picked up, without ugly
> non-harmonic components.
ME: WERE I to design a sampling system, I'd go with the Nyquist theorem over
the Steinman corrolary.
George
> -----Original Message-----
> From: owner-olympus@xxxxxxxxxxxxxxx
> [mailto:owner-olympus@xxxxxxxxxxxxxxx]On Behalf Of Jan Steinman
> Sent: Saturday, March 15, 2003 12:49 PM
> To: olympus@xxxxxxxxxxxxxxx
> Subject: [OM] Re: A conspiracy?-another correction
>
>
> >From: "George M. Anderson" <george@xxxxxxxxxxxxxxxxxx>
> >
> >Sorry, Jan but Joe and John were correct.
>
> Thanks, George -- I knew I could count on you to have the
> definitive word on just about anything.
>
> I'll just get back to my "day job" of designing signal sampling
> systems now.
>
> You guys are all confusing "rate" with "frequency." But I guess
> you can believe anything you read on a website.
>
> --
> : Jan Steinman -- nature Transography(TM): <http://www.Bytesmiths.com>
> : Bytesmiths -- artists' services: <http://www.Bytesmiths.com/Services>
>
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