The filters in the Pixelate submenu sharply define a selection by clumping pixels of similar color values in cells.

Color Halftone

Simulates the effect of using an enlarged halftone screen on each channel of the image. For each channel, the filter divides the image into rectangles and replaces each rectangle with a circle. The circle size is proportional to the brightness of the rectangle. See Apply the Color Halftone filter.

Crystallize

Clumps pixels into a solid color in a polygon shape.

Facet

Clumps pixels of solid or similar colors into blocks of like-colored pixels. You can use this filter to make a scanned image look hand-painted or to make a realistic image resemble an abstract painting.

Fragment

Creates four copies of the pixels in the selection, averages them, and offsets them from each other.

Mezzotint

Converts an image to a random pattern of black-and-white areas or of fully saturated colors in a color image. To use the filter, choose a dot pattern from the Type menu in the Mezzotint dialog box.

Mosaic

Clumps pixels into square blocks. The pixels in a given block are the same color, and the colors of the blocks represent the colors in the selection.

Pointillize

Breaks up the color in an image into randomly placed dots, as in a pointillist painting, and uses the background color as a canvas area between the dots.