Digital BW, The Print

Peter,

> > > Creating the right transfer function
> >
> > "transfer function"?  I've never heard this called "transfer
> > function"...where did you get that?
>
> That's the general term.  Professionally I'm an engineer
> specializing in image processing.  I say transfer function because
> it's more correct.

I disagree that it's "more correct".  "Transfer function" is far less
precise term than LUT, or any more descriptive term for this...even tonal
curve adjustment is more precise, as that IS what is happening, no matter
how it's implemented.

> Same reason I distinguish PPI from DPI.

But these are two distinct things, and they should be distinguished.

> And I really should say "functionS" because there's actually a
> pipeline of transfer functions between the original image file and
> the dots of ink on the paper and they all need to be characterized.

I believe you're being overly pedantic calling it a "transfer function".
It's too general a term, as it doesn't describe what is happening, and it's
also not commonly used by imaging engineers when discussing simple tonal
curve adjustment..we certainly don't say "well, we'll just use a transfer
function here", we describe what is to happen, not that something is to
happen.  At least no one in my 25 years in the imaging industry has ever
used that term for simple tonal curve adjustments.  What you were describing
is merely addition, typically implemented as a LUT.  Yes, more happens after
the tonal curve adjustment before ink gets to the paper, but we weren't
talking about that.

Regards,

Austin