RE: Calculating Scan Size

From: Peter Marshall ^lt;>
Date: 02/21/04-04:42:06 AM Z
Message-id: <>

> 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
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
London's Industrial Heritage:
The Buildings of London etc:
My London Diary
and elsewhere......
Received on Sat Feb 21 04:43:10 2004

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