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 process- es. 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 my 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 example on page 91.
Unlike the brightness control in the brightness, contrast, color balance palette, the lightness control 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.
Drag the hue, saturation, or lightness slider, or enter specific values in the corresponding text box to make corrections.
Dragging each slider to the right or inputting a positive number in the text box increases the satura- tion, and lightness. The hue slider rotates the colors in the image through the color space; the maxi- mum position to the right (180°) is the same as the maximum position to the left
Two color spaces 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.
Changes will be reflected in the displayed image. Click the reset button to cancel any changes.
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ADVANCED IMAGE PROCESSING
