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Advanced image processing
Drag the hue, saturation, or lightness slider, or enter spe-
cific values in the corresponding text box to make correc-
tions; changes will be reflected in the display image.
Dragging each slider to the right or inputting a positive
number in the text box increases the saturation, and
lightness. The hue slider rotates the colors in the image
through the color space; the maximum position to the
right (180°) is the same as the maximum position to the
left (–180°). Click the reset button to cancel any changes.
Hue, saturation, and lightness palette
This palette adjusts the image in reference to the HSB color model. These controls can be used to
manipulate the color image rather than producing a realistic representation.
The HSB color model defines color based upon human perception rather than photographic
processes. Hue refers to each separate color in the model. Saturation is how vivid each colors is.
Lightness describes how bright or dark a color is in the color space.
The hue control is not a color balancing tool. It is a creative tool. When changing hue in the
palette, each color is assigned a new hue depending on the degree of rotation through the color
space. For example, a very simple color space could have three colors: red, green, and blue. I
have a red barn next to a green tree with a blue sky. Now I rotate the image in the color space;
the colors are reassigned a new hue based on the position - the barn is green, the tree is blue,
and the sky is red. The HSB color space is similar, but with many more hues; see the color exam-
ple on page 75.
Unlike the brightness control in the brightness, contrast, color balance palette, the lightness con-
trol does not change the apparent density of the colors equally. For example, with an extreme
increase in lightness, blue will not appear as light as yellow.
Click the hue, saturation, and lightness button to open
the palette.
Original color space
New color space
Two color samples are displayed at the bottom of the palette. The top bar indicates the color
space of the original image. The bottom bar displays the relative changes to the color space.
Clicking the auto-setting button adjusts the saturation automatically without affecting the hue or
lightness. Click the reset button to cancel any changes.
