RE: Calculating Scan Size

From: Peter Marshall ^lt;petermarshall@cix.co.uk>
Date: 02/21/04-04:42:06 AM Z
Message-id: <memo.20040221104258.1396A@petermarshall.compulink.co.uk>

> Phillip,
>
> > A 4x or 8x DVD burner is a great solution.
> > If it must be on CDR, consider using a fractal
> > or wavelet compression format.
> >
> > Both Genuine Fractals and MrSid have lossless capability.
> > A Genuine Fractals STN file will allow a lossless compression
> > ratio of approximately 2:1 and visually-lossless at 5:1.
> >
>
> Strictly speaking, as I understand the product, Genuine Fractals isn't
> completely lossless, perhaps I'm wrong about that though, if I could
> find my GF manual it might explain that. However the disadvantage for
> the STN file format is that it is only an 8 bit image format,
>
> > I have created visually-lossless files using MrSid with
> > a ratio of 20:1. Only a trained eye could detect a difference.
> >
>
> I don't know anything about Mr. Sid where can one find info about it?
>
> Thanks,
>
> Don

It is worth trying jpeg2000. The loss-free mode doesn't give much
compression (around 60% of full size) but in lossy mode at 100% quality on
the plugin I have cuts a 35Mb 24 bit file down to 1.7Mb with a fairly
minimal loss in quality. JP2 uses wavelet compression (like MrSID) and
supports 16 bit files and alpha channel transparency.

PC and Mac versions were available free at http://www.fnordware.com/j2k/
if you have Photoshop plugin compatible software that doesn't support JP2.

They also have a better png plugin for free, as well as xMeta, a simple
set of three plug-ins for exporting metadata from Photoshop in raw binary
form, including icc profiles.

Peter Marshall
Photography Guide at About http://photography.about.com/
email: photography.guide@about.com
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Received on Sat Feb 21 04:43:10 2004

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