RE: filmscanners: File sizes, file formats, etc. for printing 8.5 x 11and 13 x 17...

["Austin Franklin" <austin@darkroom.com>]

My understanding is different.  Halftoning is not dithering, but you can use
dithering IN the halftone process.  Halftone describes a process...as I said
in another post.  Dithering is a 'function'.  I will check out your
reference, and perhaps that reference is the source of the confusion.

The word dither means "in a state of indecision".  That doesn't sound like
it describes the actual process, at least to me.  I have used 'dither bits'
to break up regular patterns in digital signal processing, it is a common
technique.  It means flipping the LSB of every, typically, other sample.

Would you mind scanning in the referenced page(s) for me and emailing it to
me off list?  I would greatly appreciate that.

All the books I have on the subject substantiate my understanding of the
terms.  One book readily at hand "Principles of Color Proofing, Bruno, 1986"
does not even have the word "dither" in the glossary, but does have quite a
bit on halftoning.

> Half-toning is a specific kind of dithering, namely cluster-dot ordered
> dithering. Another kind of dithering is a random dither, or stochastic
> dithering. So the general term is dithering, not half-toning. You can read
> about this in sec. 13.1.2 in Foley and van Dam's classic book, "Computer
> Graphics" Second Edition. I guess it doesn't matter what Adobe says about
> it. These are old terms that have been around a lot longer than Photoshop.

> > > Austin writes ...
> > >
> > > > Now, another question...why do you call it 'dither' instead of
> > > halftone?
> > > > ...
> > >
> > >     I consider "dither" as the general term, which includes
> > > "halftone".  "Halftone" would seem best applied to traditional
> > > methods, and not include some of the newer techniques ... e.g.,
> > > "random" or "stoichastic" dithering ... but that may be just me  :o)
> > >
> >
> > Well, I asked because someone wanted to 'discuss' with me that
> halftone is
> > not the proper term, that dither was.  I've been in digital
> > imaging for over
> > 20 years, and I believe halftone is still appropriate to call
> the overall
> > process...and dither is but one method employed in
> halftoning...so I think
> > you have it reversed...and apparently Adobe agrees with me if you check
> > their technical articles on PhotoShop on halftoning...so I was
> curious why
> > you, also, called it that instead of halftoning.  Not saying
> you're wrong,
> > but my understanding is different.  Check the Adobe site and let me know
> > what you thing...  If you want the URLs, I can dig them up.
> >
> > Regards,
> >
> > Austin
> >
> >
>