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Subject: Re: data compression
Date: Thu, 15 May 2008 10:29:02 +0000 (UTC)
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"Ahmed " <mogwari2000@yahoo.com> wrote in message <g0gl00
$nhs$1@fred.mathworks.com>...
> I have a large database that containing images.  Every 
> image is described with a matrix (X) which has two 
vectors 
> one vector is the horizontal projection and the other 
> vector is vertical projection of the image. These vectors 
> have the same length (d). For example let d=512, this 
> means that the size of (X) = 512x2. All the values are 
> positive floating point numbers.
> My problem is how I can simplify the matrix X in a new 
> vector (Y) that also represents the image but with a 
> little information? 
> Can any one give me an idea?
> My idea is to make a code that represents the two vectors 
> in the matrix and also to distinguish images from each 
> other
> 
My original question still stands, do you need absolute or 
approximate compression?

Check Wavelet compression, excellent demo in the Wavelet 
toolbox.

Regards

Dave Robinson