Date sent: Sun, 09 Jun 2002 18:59:45 -0400
Send reply to: filmscanners@halftone.co.uk
From: "Johnny Johnson" <jjohnso4@attbi.com>
To: doogle@doogle.com
Subject: [filmscanners] Re: Archiving and when to
sharpen(was:Color spaces for differentpurposes)
> At 05:32 PM 6/9/02 -0400, Mac wrote:
>
> >Wow, are you sure? The LZW TIFF was *larger*?
> >That's unusual.
>
> Hi Mac,
>
> Thanks for asking - it looks like the original TIFF file that I grabbed
> must have already been saved with lwz compression. So, I did the
> experiment again using a fresh scan of a different slide with the following
> results:
>
> TIFF: 56,264 kb
> TIFF with lzw compression: 35,364 kb
> JPG with Photoshop level 12: 18,453 kb
>
> So, in both this case and the previous one, the JPG with level 12
> compression is ~ 1/2 the size of a TIFF with lzw compression.
>
> Thanks again for bringing my mistake to my attention,
> Johnny
That makes more sense.
Contrary to what Anthony Atkielski wrote, I have NEVER seen a LZW Tiff come out
larger than an uncompressed one, regardless of exact pixel content.
I have also never seen a compressed TIFF come out equal to or smaller than a
JPEG
at the same pixel dimensions, regardless of how how the quality setting of the
JPEG.
The only time I've seen a compressed file come out larger than a non-compressed
one
is when using .zip on a JPEG.
Mac McDougald -- DOOGLE DIGITAL
500 Prestwick Ridge Way # 39 - Knoxville, TN 37919
doogle@doogle.com 865-540-1308
----------------------------------------------------------------------------------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or
body
