preserveAlpha (ConvolutionFilter.preserveAlpha property)

Indicates what the convolution applies to. A value of false indicates that the convolution applies to all channels, including the alpha channel. A value of true indicates that the convolution applies only to the color channels. The default value is true.

Example

The following example changes the preserveAlpha property of filter from its default value of true to false.

import flash.filters.ConvolutionFilter;
import flash.display.BitmapData;
    
var preserveAlpha:Boolean = false;
var filter:ConvolutionFilter = new ConvolutionFilter(3, 3, [1, 1, 1, 1, 1, 1, 1, 1, 1], 9, 0, preserveAlpha);

var myBitmapData:BitmapData = new BitmapData(100, 80, true, 0xCCFF0000);

var mc:MovieClip = this.createEmptyMovieClip("mc", this.getNextHighestDepth());
mc.attachBitmap(myBitmapData, this.getNextHighestDepth());
myBitmapData.noise(128, 0, 255, 1 | 2 | 4 | 8, false);

mc.onPress = function() {
    myBitmapData.applyFilter(myBitmapData, myBitmapData.rectangle, new Point(0, 0), filter);
}