Xerox Document WorkCentre 480cx, Онлайн руководство пользователя

Страница: 237 / 359

Book
TOC
Chapter
TOC
Search
Quit
6-37
Conversely, all pixels in the original that are brighter than the
current highlight point are now completely white in the processed
image.
Setting the highlight point to 200 renders all pixels greater than or
equal to 200, on the original, completely white in the processed
image. Similarly setting the Shadow point to 200 renders all
points less than or equal to 200, on the original, completely black
in the enhanced image. Photographers often refer to these effects
as "high-key" or "low-key". High-key is an image pushed to the
white end, and low-key is an image pushed to the black end of the
tone curve.
The Midtone is a relative measure of the gamma of your monitor.
The scale for Midtone ranges from 0 to 255. The gamma curve is
on a geometric series. This means that at a value of 255 it tends to
infinity.
The Midtone is bound by the Shadow and Highlight terms and
cannot exceed them at any time. So, if the Highlight is set to 255
and the Shadow is set to 0, a gamma of 1 is equal to a Midtone of
128. Similarly, if the Shadow is set at 200 (lower boundary) and
the Highlight is set at 220 (upper boundary), a gamma of 1 is equal
to a Midtone of 210.
Previous Page Next Page