Archived posting to the Leica Users Group, 2001/07/24

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Subject: RE: [Leica] Re: Digital Leica and reality
From: "Austin Franklin" <darkroom@ix.netcom.com>
Date: Tue, 24 Jul 2001 10:55:55 -0400

> [your claimed that]the Piezo driver
> "invents" data.  It simply does not.  It is a deterministic transformation
> of pixels to printer dots.
>
> I specifically call this "invented".  There is no capture pixel duplicated
> precisely in the output dot. The dots would get huge quickly,  which would
> give blocky hard copy outputs.  The output dot is made to approximate the
> input pixel using multiple dots of ink, determioned by the
> driver.  In that
> deterministic algorithm, the decision is made to enhance the edges of the
> dot,

You are missing some understanding.  NO edge of any "dot" is enhanced at
all.  A printer dot is only a printer dot, and it can only print ONE dot of
one color in one position with one density.  It can vary it's size, it can
vary it's color with the given set of inks it has to work with, and it can
vary it's position.  That's it.

You are confusing halftone cells with printer dots.  The driver can also use
what is called a "random" dither pattern, which is not fixed cell
based...and random is not entirely random in the sense you think it may be.

> add pigment to the center of the pixel, change color to the
> surrounding
> dots, subtract density to the edges, use 4 color to approximate one color,
> etc.  I can clearly see the difference in what this driver does and a 1:1
> pixel by pixel representation to the output of the input data.

That does NOT mean the Piezo driver is "inventing" data.  It certainly is
transforming or processing data.  Entirely different.

In fact, the chemical process actually DOES invent data.  Your film
"invents" data when it records the image.  The enlarger lense, and paper,
"invent" image data, as well as your developer!

The fact is, the data sent to your printer  can be converted directly back
to the original scanned image...perfectly with no difference...  You can not
do that with a chemically printed image.

Frank, I think you're out of "data" here ;-) Suffice to say I really believe
you are missing some understanding on how the process of digital acquisition
and output works.  I believe I understand what you are trying to say, but it
just isn't so.