According to author Roger Pring, you may find yourself getting into the Photoshop Filters menu out of curiousity or on a rescue mission. Either way, most people feel daunted by the 109 filters from which to choose. Some are used for effect while others are used for dealing with perceived flaws in the original image. In Photoshop Filter Effects Encyclopedia, Pring ties them into groups to make them more understandable.
To do this, he breaks them down into thirteen groups of regular filters. He then takes an image and uses that image to explore the differences between the filters. He also uses other images to help reveal other points about the filter. This book truly lives up to its name of being an encyclopedia of filters.
Pring begins with "The Artistic Filters." These 15 filters are what are called the painterly techniques that include colored pencil, sponge, dry brush, film grain, pastels, and watercolor, among others. In "Blur filters," there are 10 filters that will help you improve some photos taken under difficult situations, or when you want to draw attention to a specific area and downplay another.
"Brush Stroke Filters" will show you how to use the eight brush filters. These include Dark strokes, Crosshatch, Ink outlines and Spatter. "Distort Filters" will explore the thirteen filters such as Ocean Ripple, Glass, Ripple, ZigZag, Shear and Twirl.
The "Noise Filters" will explain the use of Despeckle, Add Noise, Reduce Noise, Median, as well as Dust and Scratches. These are as useful in restoring photos as well as being able to give them a more natural film look. "Pixelate Filters" are generally used for effect rather than improvement of an image. These include Mosaic, Fragment, Facet and Pointillize.
The "Render Filters" include Fibers, Clouds and Lens Flare. They can be used to add effects for background as well as some texturing. "Sharpen Filters" will help you fix some of the problem images that could be improved by a little sharpening. The "Sketch Filters" use the foreground and background colors to produce marks or strokes. These effects include Chalk, Charcoal, Chrome, Note Paper, Photocopy and Plaster.