User Guide

CHAPTER 13. FILTERS 153
settings of the image. This enables you to get an idea of how the image will print out as
you adjust settings.
Below that there are eight sliders:
Brightness (0-2.0, default 1.0) adjust the brightness of the image.
Contrast (0-4.0, default 1.0) adjust the output contrast.
Cyan, Magenta, Yellow (0-4.0, default 1.0) adjust the cyan, magenta, and yellow in
the output. These should not normally need to be adjusted very much; even very
small adjustments can go quite a long way to restoring color balance..
Saturation (0-9.0, default 1.0) adjust the color brilliance (saturation) of the output.
Saturation of 0 means pure gray scale, with no color. Saturation of 9.0 will make
just about anything but pure grays brilliantly colored.
Density (0.1-2.0, default 1.0) adjust the density (amount of ink) in the print. The den-
sity is automatically corrected for the particular printer, resolution, and, in some
cases, paper choices. If solid black in the input is not solid in the print, the density
needs to be increased; if there is excessive ink bleed-through and muddy dark
colors, the density should be decreased.
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The density will not increase beyond a certain amount no matter what
the slider is set to.
Gamma (0.1-4.0, default 1.0) adjust the output gamma. The gamma value is auto-
matically corrected for the choice of printer; this is used if you believe the auto-
matic setting is incorrect.
Dither Algorithm There is also a selection box for the dither algorithm to be used.
There are currently seven choices:
• Adaptive Hybrid usually yields the best output quality. It chooses a modi-
fied Floyd-Steinberg error diffusion algorithm or ordered dithering depend-
ing upon the image characteristics.
• Ordered uses a pure ordered dither. It generally yields excellent quality for
simple black and white or four color printers without variable drop size or
drop modulation. It is not recommended if high quality is desired on six
color printers. It is considerably faster than Adaptive Hybrid.
• Fast also uses a pure ordered dither, but uses a very simple black model
and makes no attempt to handle multi-level (6-color, variable drop size, or
drop modulation) at all cleanly. It is substantially faster than Ordered dither.
The quality tends to be quite poor except on simple four color printers. On
three color printers, quality is probably competitive with anything else.
• Very Fast is similar to Fast, except that it uses a very simple dither matrix
that can be looked up much more quickly than the matrix used in the Fast
dither. For simple pure black and white images dominated by horizontal