
Visual filters modify the appearance of a control. In fact, they can totally take over the visual output of a control when applying their effect. A good example of a visual filter is the alpha filter. It blends its target into the background. The author controls the amount of blend (or opacity). Opacity is expressed as a percentage. For example, the following HTML causes the image to be 20 percent opaque:
<img id=sample src=sample.jpg style="filter:alpha(opacity=20)">
Internet Explorer 4.0 supports a range of visual filters, shown in the following table, from the aforementioned alpha blend to a light filter that simulates colored lights shining on the control.
| Filter effect | Description |
| Alpha | Sets a transparency level. |
| Blur | Creates the impression of moving at high speed. |
| Chroma | Makes a specific color transparent. |
| Drop Shadow | Creates an offset solid silhouette. |
| FlipH | Creates a horizontal mirror image. |
| FlipV | Creates a vertical mirror image. |
| Glow | Adds radiance around the outside edges of the object. |
| Grayscale | Drops color information from the image. |
| Invert | Reverses the hue, saturation, and brightness values. |
| Light | Projects light sources onto an object. |
| Mask | Creates a transparent mask from an object. |
| Shadow | Creates a solid silhouette of the object. |
| Wave | Creates a sine wave distortion along the x-axis and y-axis. |
| XRay | Shows just the edges of the object. |
To experiment with filters use the following samples provided with the Internet Client SDK.
Filters Wizard
Wave Filter Wizard
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