Digital BW, The Print

Austin,

> 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.

Thank you, this makes more sense.  It is very frustrating when the printing
companies I have dealt with are not aware of the different options when I
request an alternative screening method. I have gone thru four different
printers until I found one that could at least talk to me about color
management and work flow technique.  Two of these printers told me outright
that I could not get a CMYK profile for their presses because you can only
profile an RGB output device!!!  I left them right away.

> 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.

I'll get this book, I have others but this sounds like the book I need to
put it all together.

> 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.

I'm curious about how they can deliver a print without the moire pattern
visible while using a halftone technique other than stochastic... There must
be other techniques I'm not familiar with.

So offset press prints with visible moire patterns are "ordered dither", the
prints without are "stochastic dither"... or something else?  Then are
inkjet prints "stochastic dither" or are they a different beast altogether?

Carolyn