Blur filters blur images, or parts of them, in various ways. If there is a selection, only the selected parts of an image will be blurred. There may, however, be some leakage of colors from the unblurred area into the blurred area. To help you pick the one you want, we will illustrate what each does when applied to the image shown at right. These are, of course, only examples: most of the filters have parameter settings that allow you to vary the magnitude or type of blurring.

This category describes the following filters:

The most broadly useful of these is the Gaussian blur. (Don't let the word "Gaussian" throw you: this filter makes an image blurry in the most basic way.) It has an efficient implementation that allows it to create a very blurry blur in a relatively short time.

The Selective Blur filter allows you to set a threshold so that only pixels that are similar to each other are blurred together. It is often useful as a tool for reducing graininess in photos without blurring sharp edges. (In the example, note that the graininess of the background has been reduced.) The implementation is much slower than a Gaussian blur, though, so you should not use it unless you really need the selectivity.

The Pixelize filter produces the well-known "Abraham Lincoln" effect by turning the image into a set of large square pixels. (The Oilify filter, in the Artistic Filters group, has a similar effect, but with irregular blobs instead of perfectly square pixels.)

The Motion Blur filter is divided in Circular, Linear, and Zoom.

The Circular Motion Blur filter blurs in a rotational direction around a center that you can set.

The Linear Motion Blur filter blurs in a direction that you can set.

The Zoom Motion Blur filter blurs in a radial direction around a center that you can set.

Finally, the Tileable Blur filter is really the same thing as a Gaussian blur, except that it wraps around the edges of an image to help you reduce edge effects when you create a pattern by tiling multiple copies of the image side by side.