Smoothing with the Facet and Median Filters

One application for blurring an image is to reduce dust and scratches, or to smooth away sharp edges. I show you how to use the versatile Facet and Median filters to soften an image. Although the Facet and Median filters smooth images by eliminating some detail, you can compensate for the blurring effect by applying Unsharp Mask with a low radius setting to sharpen things up a little.

The Facet filter
Facet breaks up an image using a posterizing effect. It gathers up blocks of pixels that are similar in brightness and converts them to a single value using geometric shapes. (When you posterize an image, you reduce it to a very small number of tones.) The geometric shapes make the image look more randomly produced, while eliminating much of the banding effect you get with conventional posterizing filters. The effects of the Facet filter are subtle, and best viewed close-up. The original image contains some dust, scratches, and a few other defects. Instead of retouching them one by one, I used Facet.

Facet is a single-step filter, so you don’t need to adjust any controls. Just choose Filter-->Pixelate-->Facet and evaluate your results. You can apply the filter multiple times. However, even one application smoothes out the picture and eliminates the worst of the artifacts. If you apply the Facet filter multiple times, your image will take on a pointillist, stroked look that becomes obvious. Maybe you wouldn’t frame your image but using the filter again and again can yield quite interesting special effects.

The Median filter
The Median filter (look for it in the Filter-->Noise menu) operates similarly to the Facet filter in that it reduces the difference between adjacent pixels by changing the values of some of them. In this case, it assigns the median values of a group of pixels to the center pixel in the group. Unlike the Facet filter, the Median filter gives you a bit of control. You can choose the radius of the group that Photoshop will use to calculate the median value. Median tends to make an image look a bit blurrier because it reduces the contrast of adjacent pixels. However, it does a good job of smoothing the image and removing artifacts.