Technical data

38 Manipulating Images
Click on the View Original button above each illustration to view the
image as it appeared before the filter was applied. Click on the Apply
Effect button to see the after state.
Here’s a quick summary of the PhotoPlus image adjustments.
♦ Brightness/Contrast: Brightness refers to overall lightness or
darkness, while contrast describes the tonal range, or spread
between lightest and darkest values.
♦ Hue/Saturation/Lightness: Hue refers to the color's tint—what
most of us think of as rainbow or spectrum colors with name
associations, like "blue" or "magenta." Saturation describes the
color's purity—a totally unsaturated image has only grays.
Lightness is what we intuitively understand as relative darkness or
lightness—ranging from full black at one end to full white at the
other.
♦ Replace Color lets you “tag” one or more ranges of the full color
spectrum that require adjustment in the image, then apply
variations in hue, saturation, and/or brightness to just those color
regions.
♦ Gamma adjusts the red, green and blue in an image to compensate
for the way the monitor displays colors.
♦ Threshold creates a monochromatic (black and white) rendering.
You can set the threshold, that is the lightness or gray value above
which colors are inverted.
♦ Equalization evenly distributes the lightness levels between
existing bottom (darkest) and top (lightest) values.
♦ Stretch establishes new bottom and top values and spreads out the
existing lightness levels between them.