Since we've been through this only 6 or so months ago, last time
speaking about grey scale (black and white) laser printers, that time,
and I wasted my time trying to explain it then, I will just repeat the
posting again. (in a rude top posting, no less)... perception of number
of colors represented in a non-continuous tone printing process is
directly related to the dot resolution of the printer, particularly in a
laser printer which uses relatively opaque colorants.
Certainly, sloppy drivers, poor distribution of the dots due to a bad
the screening formula, smearing, banding or poor dot accuracy, can muddy
an image, but all things being equal, and even some things not being
equal, gradient levels and color accuracy are related to dot size and
resolution.
Although not accurate that this is "only in one bit machines", in a
basic sense, each toner color a laser printer prints is nearly one bit
color depth, in that the color application isn't given a great deal of
variation, although dot size and shape and to some extend density, can
be varied. Laser printers just aren't continuous tone devices and as
such, higher resolution of the dots will continue to determine ability
to make effective gradients.
To repeat the explanation from 6 months ago:
Although your message appears to have gotten scrambled, even if I try to
translate it, it still doesn't seem to make sense relative to what I am
speaking of.
The number of greyscale levels perceivable on a black and white laser
printer image are DIRECTLY related to the resolution of the printer.
Laser printers use screens or error diffusion of other dot patterns to
create a greyscale level in a "cell". Since a laser printer, in theory,
can only produce one binary condition per dot position (either on
(black) or off (white)), the perceived greyscale is directly determined
by the number of combinations or percentage of on or off dots within an
area that can be produced. Since humans are the viewers, viewing
distance and visual acuity determine at what point we blur an area into
a continuous tone, whether it is or not in fact. Very few printing
techniques are true continuous tone. Photographic images and dye sub are
probably the closest.
Inkjet, laser, etc are not, as they can only lay down one density of
color per dot based upon their inks or toners. Some can make larger or
smaller dots, but very few other than dye sub actually have varying
density of ink per location.
Getting back to B&W lasers, if a cell were 2 dots by two dots, as an
example, the options would be:
4 black
3 black one white
2 black 2 white
1 black 3 white
4 white
or five steps from pure black to white.
If the cell were made up of smaller dots and it was 3 dots by 3 dots,
that same area could represent several more levels from black to white.
If that same area were able to have 16 dot in each direction, or a total
of 256 dots which could either be black or white, the number of
perceived greyscale patterns would increase still further.
Therefore, in black and white laser printing, the resolution directly
determines the perceived number of greyscale levels the printer can
represent.
Art
