Introduction to Filters in IE 5.5 and Up

One of Internet Explorer 5.5's main features is its support for a rich set of filters and transitions. Filters and transitions allow you to create visual effects that are very difficult to create otherwise. They also enhance and extend your arsenal for developing interactive Web pages. The difference between filters and transitions is that filters are static while transitions are dynamic. Filters affect the way content is displayed. They let you modify the original content in many different ways. You see only the final result, after the filter application. Mirroring an image is a simple example for a static filter. What you see on the Web page is the image after it has been mirrored. You can imagine what the original image is, but you don't see it explicitly on the page. The supported filters are Alpha, BasicImage, Blur, Chroma, Compositor, DropShadow, Emboss, Engrave, Glow, Light, MaskFilter, Matrix, MotionBlur, Pixelate, Shadow, and Wave.

Transitions, on the other hand, affect how content changes along a time interval. Content changes between an initial image and a final image. You specify with transitions how you want the image to change from its initial specification to its final specification. The CheckerBoard transition is one of the supported transitions. The starting image is divided into several rectangles, and then each rectangle rolls to the right, revealing the appropriate rectangles in the final image. The transition takes time and supposed to be noticeable. The supported filters are Barn, Blinds, CheckerBoard, Fade, GradientWipe, Inset, Iris, Pixelate, RadialWipe, RandomBars, RandomDissolve, Slide, Spiral, Stretch, Strips, Wheel, and Zigzag.

In this column we introduce the world of filters. We'll teach you the basics of filters: how to define them, use them, and manipulate them. We'll teach you several rules to remember when working with filters, and to which objects filters cannot apply. We'll also show you how to add additional filters on the fly, and how to script filters through their properties and methods.

In this column you will learn:

• How to define a single filter
• How to define multiple filters
• How to script filters
• How to use the filter property

Next: How to define a single filter