Digital BW, The Print

Tyler,

> snip
> > This was the problem I think... On the one hand.. we are speaking
> > greyscale.. you have been speaking RGB,
> No, I'm not. Again, four channels, four. Printed through a four channel
> driver, to four inks.
> Sorry Keith, you're still not grasping what's happenning in a partioned
> quad ink four channel file. But really, none of us actually need to.

It doesn't matter how many inks, a grayscale file is ONE channel, period.
The file that is sent to the Piezo driver is ONE channel when using the
traditional Piezo software.  That isn't questionable.

Out of that 8 bit data, you can ONLY achieve 256 maximum steps, period.
That, also, is not debatable.  IF (and I doubt it) the driver decides to
MAKE UP more tones, they are NOT real tones.

> > Remember that we are starting with a file with only 256 levels anyway..
> Not really, Austin was quoting Jon's statement about Piezo from a 16
> bit file, far more than 256 levels.

No, I was quoting from the 1000 comment in this case, which is the
"traditional" Piezo claim, and that is only 8 bits, and therefore is only
256 levels.

> Note that any 16-bit image saved out of Photoshop will have, at a
> maximum, 32769 unique levels per channel, not 65536 as one might
> expect.  This is a
> limitation of Photoshop's internal architecture.  A true 16-bit image
> may therefore lose levels and number of unique colors simply by opening
> and saving
> with Photoshop.  The limited Photoshop style 16-bit encoding is
> detected and reported by Levels.

This is simply silly.  If this is the case, then simply save it as TIFF, and
you should have no loss problems.  Anyway, even if this does happen, it is
irrelevant to this discussion.  A 16 bit grayscale file has the ability to
have 64k possible values per pixel, period.  If Photoshop clips the file to
15 bits, then it isn't a 16 bit file.

It also appears that Bruce is talking about RGB files.  People who use
Piezo, don't use RGB files...

Austin