Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Peter Nelson 
<peter@s...>" <peter@s...> wrote:

> In this thread people talk about "The Epson Driver" but my
> guess, as a former inkjet driver writer, is that different
> Epsons have different drivers, or at least different 
> algorithms in different situations.   The tests I've run
> on black-only printing on the 2200 show that source 
> resolution holds up pretty well but the images are contrasty,
> which suggests to me that they are using something close to
> a fixed cell size and trading away tonal range to keep 
> spatial resolution.   However, the cell size may have nothing
> to do with incoming image resolution - the driver probably
> RESAMPLES the incoming image.   If this is the case there
> may be, if not an "optimal" resolution, then at least a 
> maximum one.

On my website I have hi-res scans of a series of tests 
I ran on my Epson 870 showing that it could reliably 
distingush lines 1 original-image-pixel apart at 300 
PPI, and even 600 PPI in some cases.   This suggests to
me that they are NOT interpolating between original 
image pixels when dithering.  They may be upsampling 
to something higher, and THEN interpolating between the
resampled pixels.  I hope to run such tests on the 2200
soon.

One interesting test would be to have two image pixels
next to each other with complementary colors, so that 
if it resamples first, using an interpolative algorithm
it will be forced to generate a new pixel of a different
color that would show up on the print that way.