[filmscanners] RE: JPEG2000 > Paul

["Paul D. DeRocco" <pderocco@ix.netcom.com>]

> From: Nagaraj, Ramesh
>
> I curios to know, How can we to verify that compression is loss-less?
>
> Loss less compression suggests that J2K can be used for archiving also.
> Am I right here?
>
> Few extra seconds for compression is not a problem for me, as
> long as I can reduce my CD bulk.
> So, Can I start archiving using J2K instead of TIFF?

I wouldn't obsess too much about lossless compression. If I take an image
file of some bright blue cloudless sky, either from a digicam or a scanned
slide, and look at the numbers, they have up to five units (peak-to-peak) of
noise in them. That is, the blue value may jump around between, say, 180 and
185 in a very small area that looks solid to the eye. After saving an
reloading an image in a lossy format, some pixel values may be off by one or
two. That's therefore an utterly insignificant loss. By tolerating that
small additional error, you can get 10:1 compression instead of 2:1.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@ix.netcom.com

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