Re: Compression: was: filmscanners: real value?

["Alan Tyson" <AlanTyson@bknowl.freeserve.co.uk>]

Michael,

For those of us working at 2700dpi....

When you've got a final image with which you're really
happy, I find Ed Hamrick's choice of "90% jpeg quality" or
my own choice of "15% compression" in PaintShopPro to be
barely distinguishable at a pixel level from the original.

This typically saves a 27MB uncompressed 24-bit colour
photographic image as just over 2MB, and means 300-odd
instead of 25-odd images on a CD-R. Also, on my antique
2-year-old machine, reading and decompressing a 2MB jpeg is
enormously quicker than reading a 27MB tiff from disk or CD.

However, if you ever want to rework the material and do more
twiddling, obviously it's better to stick with lossless
compression.

Regards,

Alan T

----- Original Message -----
From: Michael Wilkinson <michael@infocus-photography.co.uk>
To: <filmscanners@halftone.co.uk>
Sent: Thursday, February 01, 2001 8:03 PM
Subject: Re: filmscanners: real value?


> I have to admit to an ignorance on compressing files in
gereral
> I use LZW when Im storing on my server  and have not
bothered with other
> methods simply because in my early digital days I was
shown how badly
> jpeg images are degraded ..........