26 Jun
2004
26 Jun
'04
10:38 p.m.
On Sat, 2004-06-26 at 21:30, Tom Owad wrote:
I was doing 150dpi greyscale jpegs. I've changed
to 400dpi 1bpp tiffs,
Personally I do greyscale TIFF images at 8bpp - I wouldn't want to risk
something not being able to process the data at a later date, and
storage is cheap.
I'm not set up for messing around with images on the system I'm typing
this on in order to test, but if using 4bpp results in a file size
reduction then that would probably be sufficient (I can't remember how
TIFF handles 'odd' palette sizes when encoding the pixel data)
Personally I find just looking at stuff encoded at 1bpp can be hard on
the eyes due to harsh pixellated edges on text. Plus if you're dealing
with source media that's dirty, faded, printouts, or photocopies of
originals then encoding at 1bpp could rule out any later OCR process.
Storage is cheap these days - go for maximum possible quality (and
archive the data elsewhere, keeping your own lower quality copies if you
don't have the storage space).
Of course if you're just doing this for your own personal benefit then
it's less of an issue - but if you're doing it to preserve data for
others then it makes sense to only have to scan stuff once!
cheers,
Jules