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Disguising a Reference So Others Can Test Your Filter

Say someone boasts about having a new filter that, in certain situations, can reduce noise more and faster than any other filter?

Is there any way to encode a reference that isn't directly identifiable but still useful as a reference? That way the reference could be posted along with the noise for the test.

One way might be to make the noise in the reference the negative of the noise in the signal times some factor. Without the correct factor, without the SNR, it could be difficult or impossible to recover the original reference or signal.

Bret Cahill

Reply to
Bret Cahill
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But 'reduce noise' isn't something a filter does. It separates a known type of signal from a signal + distortion + noise input, and ONLY if the signal is known in character can the filter function be evaluated.

Reducing noise/signal ratio usually results in the as-filtered data having less degrees of freedom than the initial data, i.e. it reduces a hundred points (one hundred nearly-independent numbers) to three numbers. There's potentially only

3 noise components in the result, so the noise is lessened (by a factor of perhaps sqrt(100/3), while the signal can be nearly complete (down by a factor of circa 1.0).
Reply to
whit3rd

The formulation of your question is a little less than complete and coherent. But you might get an answer by clarifying your terms and purpose.

What do you mean by "reference"?

How does the "reference" relate to testing a filter?

What parameters do you wish to demonstrate?

What information are you trying to obscure?

Dale B. Dalrymple

Reply to
dbd

(snip)

As I replied to Jerry's post, see the wikipedia page Trusted_client.

The problem of distributing software source, such that the recipient can use it but not modify or reverse engineer it comes up often, but there is no easy answer. (More often for HDL (hardware description language) code, but it is the same problem.

-- glen

Reply to
glen herrmannsfeldt

Any one in particular you have in mind?

The usual way to do these things is to publish a method of design in one of the journals. That way the algorithm to design the filter is reviewed by people who ought to know the subject at hand.

What use would the filter be, then? It doesn't work unless you know the exact noise that corrupts the signal? It's a ridiculous idea.

Rune

Reply to
Rune Allnor

That's not a question. Is English your native language?

But, why would you want it to not be directly identifiable?

Is this a one dimensional signal or an image? I bet that I can detect such an image "reference" noise by visual inspection with the "signal" noise.

Wrong.

Y1 =3D X + E

Y2 =3D C*E

where C is unknown scalar, X =3D uncorrupted signal matrix, E =3D noise matrix

Solve:

min || Y1 + A*Y2 || A

A =3D -1/C

E =3D -A*Y2

X =3D Y1 + A*Y2

Reply to
aruzinsky

Just get any ol' sound source, like a recording of "The 1812 Overture," and sum it with some pseudorandom noise, such that either could be recovered with a correlator of some kind?

Good Luck! Rich

Reply to
Rich Grise

Brett has a lot of these.

Hey, at least he's thinking!

Cheers! Rich

Reply to
Rich Grise

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