[OSGeo-Discuss] 'lossless' JPEG2000

[Traian Stanev]

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: discuss-bounces at lists.osgeo.org [discuss-bounces at lists.osgeo.org] On Behalf Of Bruce.Bannerman at dpi.vic.gov.au [Bruce.Bannerman at dpi.vic.gov.au]
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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