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From: M Ladderman on 15 Mar 2010 11:18
Hi all,

Thanks for the comments. The reason why I want to apply such a constraint is because it is supposed to reduce the error of estimating spectrum from RGB singals using wiener estimation.
See this paper (I hope you guys can access it):
Title: Evaluation and unification of some methods for estimating reflectance spectra from RGB images
By: Ville Heikkinen, Reiner Lenz, Tuija Jetsu, Jussi Parkkinen, Markku Hauta-Kasari, and Timo Jääskeläinen

Maybe I misunderstood the text, but it seems to me contraining the crosscorrelations in the wiener estimation between 0 and 1 is reducing error of the estimation on to whole (this does not hold for the training set as I understand it, because this set is best explained by the unconstrained parameters).

I tried contacting the authors, but I do not get much feedback.

Thanks I hope this explains my problem a bit.



"John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hnipcm$oub$1(a)fred.mathworks.com>...
> "M Ladderman" <mirresimons(a)gmail.com> wrote in message <hni9q0$6ln$1(a)fred.mathworks.com>...
> > Is this is a stupid question or is the answer not easy. thanks for reading this mssg again, sorry to move it up in this way but I am struggling with it.
> >
> >
> > "M Ladderman" <mirresimons(a)gmail.com> wrote in message <hndolo$rqf$1(a)fred.mathworks.com>...
> > > dear all,
> > >
> > > I want to constrain the crossCorr function to return parameters/solutions between 0-1, because a priori I do not expect any negative relationships.
> > >
> > > Is there an easy way to do this that I am overlooking, thanks.
>
> Rune says it all. Just because you believe something
> is true about the correlations does not mean that it
> will in fact come out that way.
>
> If wishes were horses, beggars would ride.
>
> If you absolutely want it to happen, and are willing
> to "cook the books", then just replace any negative
> correlations with zero. Problem solved.
>
> John
> John
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