Teach Yourself Adobe Photoshop CS2.pdf - Online Public Access ...

This document was created by an unregistered ChmMagic, please go to http://www.bisenter.com to register it. ThanksYou can apply the Blur filter several times to get the effect you want, or you can move on to Gaussian Blur (Filter BlurGaussian Blur), which is a more controllable filter. It uses a mathematical formula (the Gaussian distribution equation, which results in abell curve) to calculate the precise transition between each pair of pixels. The result of this is that most of the blurred pixels end up in themiddle of the two colors or values, rather than at either end of the spectrum. This produces a generalized blur that neither darkens norlightens the image.The Gaussian Blur dialog box, shown in Figure 14.9, lets you determine exactly how much blur to apply by setting a Radius value from0.1250. You can also use it to anti-alias the edges of an object, and to blur shadow areas when you want to create a drop shadow effect.Even at fairly low settings, it has quite a dramatic effect. In Figure 14.9, notice how the subject's eye and cheek wrinkles, obvious in theprevious picture, are almost gone in the Blur preview area.Figure 14.9. Smaller numbers give you less blur.Gaussian Blur is a useful retouching tool when applied to an area within the picture that you want to de-emphasize. In Figure 14.10,there's a small lizard sunning herself on the rocks, but her protective coloration makes her kind of hard to see in the image on the left. If Iselect the lizard and apply a mask to hide her, I can blur the rest of the scene and call attention to the critter (see the image on the right).Figure 14.10. Selective blurring is a helpful tool.