Thursday, 5 April 2012

Alters color saturation, or contrast in Grayscale mode

The Sponge tool is a retouching tool used to alter the saturation of a portion of an image. It is reminiscent of the sponges used by watercolor artists to soften (or even remove) a color that has already been lain on the canvas.

The Sponge tool works in two modes:
Color values are brought towards a neutral gray of similar lightness.
Color values are made more vibrant.
RGB and CMYK color values are compared to their closest HSL equivalent. Lab color values are simply manipulated along their a and b axes.
Newer versions of Photoshop have the "Vibrance" option, which reduces clipping to primary colors (red, yellow, green, cyan, blue, magenta) or grays. The effect of the tool is lessened for color values already close to these colors.