It is not possible to *prove* a mathematical relationship by example. One would 
have to study the set of all possible images in the world and make sure they 
have no loss in order to effectively prove the claim. On the other hand you can 
*disprove* it by providing a single counterexample. That is why I pointed to 
the math of the transform, which one has hope of showing is invertible for all 
cases. Anyway, I'm not that much of an expert on wavelet compression so I can't 
do much more than point to other people's documentation.

Traian

________________________________
From: [EMAIL PROTECTED] [EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] [EMAIL 
PROTECTED]
Sent: Saturday, February 23, 2008 3:57 AM
To: OSGeo Discussions
Subject: RE: [OSGeo-Discuss] 'lossless' JPEG2000


IMO:

Thanks for the reply Traian,


I don't mean to be dismissive of this report, but I was hoping for something 
more definitive to prove that 'lossless' JPEG compressions did indeed protect 
the integrity of the data..

Perhaps its just my ignorance, but I was hoping for something along the lines 
of:

- a study of a range of typical spatial 'imagery'.

- evaluation of all spectral values for each pixel in each image before 
compression.

- 'lossless' compression  of the images

- restoration of the compressed images

- comparison of all spectral values for each pixel in each restored image 
against the original pre-compressed values.

- definitive statement with reference to the study results.


Bruce


>
> JPEG2K supports lossless via a reversible wavelet transform with
> integral coefficients (which make it reversible, and so lossless).
> Here is a reference:
>
> http://www.ece.uvic.ca/~mdadams/publications/pacrim2001.pdf
>
>
>
> Traian
>






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