Basics of filtering display objects

Flash Player 9 and later, Adobe AIR 1.0 and later

One of the ways to add polish to an application is to add simple graphic effects. You can add a drop shadow behind a photo to create the illusion of 3-d, or a glow around a button to show that it is active. ActionScript 3.0 includes ten filters that you can apply to any display object or to a BitmapData instance. The built-in filters range from basic, such as the drop shadow and glow filters, to complex, such as the displacement map filter and the convolution filter.

Note: In addition to the built-in filters, you can also program custom filters and effects using Pixel Bender. See Working with Pixel Bender shaders .

Important concepts and terms

The following reference list contains important terms that you might encounter when creating filters:

Bevel: An edge created by lightening pixels on two sides and darkening pixels on the opposite two sides. This effect creates the appearance of a three-dimensional border. The effect is commonly used for raised or indented buttons and similar graphics.
Convolution: Distorting pixels in an image by combining each pixel’s value with the values of some or all of its neighboring pixels, using various ratios.
Displacement: Shifting or moving pixels in an image to a new position.
Matrix: A grid of numbers used to perform certain mathematical calculations by applying the numbers in the grid to various values, then combining the results.