Digital BW, The Print

> Dear Austin,
>
> My understanding is that halftone is limited to a grid pattern...
> Stochastic
> is not.

Halftone is just the process/technique, the pattern used can be anything.  I
used to design and implement (in hardware) halftone patterns for a pre-press
output company.  We used many different algorithms...and they did not have
to be grid (actually called cells) based.

A very good book on this subject is "Digital Halftoning" by Robert Ulichney.
This book is one of the bibles of digital imaging...  "Digital halftoning,
also referred to as spatial dithering, is the method of rendering the
illusion of continuous tone pictures...".  Stochastic dithering is only one
of many different halftone techniques.  The book has many chapters on random
dithering, dithering with noise, and a host of other different halftone
techniques.

> Stochastic printing does not use a grid as halftone does, that is why it
can
> achieve smoother prints, it is random, there are no rosettes patterns.

That (the Moire patterns) can be eliminated in standard cell based halftone
process.  What you are referring to as "halftoning" is actually called
"ordered dither", and as I said, is only one of many algorithms that can be
used in halftoning.