The ConvolutionFilter class applies a matrix convolution filter effect. A convolution combines pixels
in the input image with neighboring pixels to produce an image. A wide variety of image
effects can be achieved through convolutions, including blurring, edge detection, sharpening,
embossing, and beveling. You can apply the filter to any display object (that is, objects that
inherit from the DisplayObject class),
such as MovieClip, SimpleButton, TextField, and Video objects, as well as to BitmapData objects.
To create a convolution filter, use the syntax new ConvolutionFilter().
The use of filters depends on the object to which you apply the filter:
To apply filters to movie clips, text fields, buttons, and video, use the
filters property (inherited from DisplayObject). Setting the filters
property of an object does not modify the object, and you can remove the filter by clearing the
filters property.
To apply filters to BitmapData objects, use the BitmapData.applyFilter() method.
Calling applyFilter() on a BitmapData object takes the source BitmapData object
and the filter object and generates a filtered image as a result.
If you apply a filter to a display object, the value of the cacheAsBitmap property of the
object is set to true. If you clear all filters, the original value of
cacheAsBitmap is restored.
A filter is not applied if the resulting image exceeds the maximum dimensions.
In AIR 1.5 and Flash Player 10, the maximum is 8,191 pixels in width or height,
and the total number of pixels cannot exceed 16,777,215 pixels. (So, if an image is 8,191 pixels
wide, it can only be 2,048 pixels high.)
For example, if you zoom in on a large movie clip with a filter applied, the filter is
turned off if the resulting image exceeds maximum dimensions.
Indicates if the alpha channel is preserved without the filter effect or
if the convolution filter is applied to the alpha channel as well as the
color channels.
The alpha transparency value for the color. Valid values are 0 to 1.
For example, .25 sets a transparency value of 25%.
The default value is 1.
Implementation public function get alpha():Number public function set alpha(value:Number):void
bias
property
bias:Number
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The amount of bias to add to the result of the matrix transformation.
The bias increases the color value of each channel, so that dark colors
appear brighter.
The default value is 0.
Implementation public function get bias():Number public function set bias(value:Number):void
clamp
property
clamp:Boolean
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
Indicates whether the image should be clamped. For pixels off the source image,
a value of true indicates that the input image is extended along each of its
borders as necessary by duplicating the color values at each respective edge of
the input image. A value of false indicates that another color should be used,
as specified in the color and alpha properties.
The default value is true.
Implementation public function get clamp():Boolean public function set clamp(value:Boolean):void
color
property
color:uint
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The color of the glow. Valid values are in the hexadecimal format
0xRRGGBB.
The default value is 0xFF0000.
Implementation public function get color():uint public function set color(value:uint):void
divisor
property
divisor:Number
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The divisor used during matrix transformation. The default value is 1.
A divisor that is the sum of all the matrix values smooths out the overall
color intensity of the result. A value of 0 is ignored and the default is
used instead.
The default value is 1.0.
Implementation public function get divisor():Number public function set divisor(value:Number):void
matrix
property
matrix:Array
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The amount of horizontal blur. Valid values are 0 to 255. A blur of 1
or less means that the original image is copied as is. The default
value is 4. Values that are a power of 2 (such as 2, 4, 8, 16, and 32)
are optimized to render more quickly than other values.
The default value is [].
Implementation public function get matrix():Array public function set matrix(value:Array):void
matrixX
property
matrixX:Number
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The x dimension of the matrix (the number of rows in the matrix).
The default value is 0.
Implementation public function get matrixX():Number public function set matrixX(value:Number):void
matrixY
property
matrixY:Number
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
The y dimension of the matrix (the number of columns in the matrix).
The default value is 0.
Implementation public function get matrixY():Number public function set matrixY(value:Number):void
preserveAlpha
property
preserveAlpha:Boolean
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
Indicates if the alpha channel is preserved without the filter effect or
if the convolution filter is applied to the alpha channel as well as the
color channels. 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.
Implementation public function get preserveAlpha():Boolean public function set preserveAlpha(value:Boolean):void
matrixX:Number (default = 0) — The x dimension of the matrix (the number of columns in the matrix). The
default value is 0.
matrixY:Number (default = 0) — The y dimension of the matrix (the number of rows in the matrix). The
default value is 0.
matrix:Array (default = null) — The array of values used for matrix transformation. The number of
items in the array must equal matrixX * matrixY.
divisor:Number (default = 1.0) — The divisor used during matrix transformation. The default value is 1.
A divisor that is the sum of all the matrix values evens out the overall color intensity of the
result. A value of 0 is ignored and the default is used instead.
bias:Number (default = 0.0) — The bias to add to the result of the matrix transformation. The default value is 0.
preserveAlpha:Boolean (default = true) — A value of false indicates that the alpha value is not
preserved and 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.
clamp:Boolean (default = true) — For pixels that are off the source image, a value of true indicates that the
input image is extended along each of its borders as necessary by duplicating the color values
at the given edge of the input image. A value of false indicates that another
color should be used, as specified in the color and alpha properties.
The default is true.
color:uint (default = 0) — The hexadecimal color to substitute for pixels that are off the source image.
alpha:Number (default = 0.0) — The alpha of the substitute color.
Method Detail
clone
()
method
public function clone():BitmapFilter
Language Version :
ActionScript 3.0
Product Version :
Flex 4
Runtime Versions :
Flash Player 10, AIR 1.5
Returns a copy of this filter object.
Returns
BitmapFilter — BitmapFilter A new ConvolutionFilter instance with all the same properties as the original
ConvolutionMatrixFilter instance.
Examples
ConvolutionFilterExample.mxml
<?xml version="1.0"?>
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- filters/examples/ConvolutionGlowFilterExample .mxml -->
<s:Application
xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:mx="library://ns.adobe.com/flex/mx"
xmlns:s="library://ns.adobe.com/flex/spark"
creationComplete="createFilters()">
<fx:Script><![CDATA[
import spark.filters.*;
import flash.filters.BitmapFilterQuality;
import flash.filters.BitmapFilterType;
private var myOutlineConvolutionFilter:ConvolutionFilter;
private var mySharpnessConvolutionFilter:ConvolutionFilter;
private var myBrightnessConvolutionFilter:ConvolutionFilter;
private var outlineMatrix:Array = [ -30, 30, 0,
-30, 30, 0,
-30, 30, 0 ];
private var sharpnessMatrix:Array = [0, -1, 0,
-1, 20, -1,
0, -1, 0];
private var brightnessMatrix:Array = [2, 2, 2,
2, 0, 2,
2, 2, 2];
public function createFilters():void {
myOutlineConvolutionFilter = new ConvolutionFilter(3, 3, outlineMatrix, 9, 0, true, true, 0x00CC99, 0);
mySharpnessConvolutionFilter = new ConvolutionFilter(3, 3, sharpnessMatrix, 9, 0, true, true, 0x00CC99, 0);
myBrightnessConvolutionFilter = new ConvolutionFilter(3, 3, brightnessMatrix, 3, 0, true, true, 0x00CC99, 0);
outlineImage.filters = [myOutlineConvolutionFilter];
sharpnessImage.filters = [mySharpnessConvolutionFilter];
brightnessImage.filters = [myBrightnessConvolutionFilter];
}
]]></fx:Script>
<s:VGroup>
<s:VGroup>
<s:Label text="Original Image"/>
<mx:Image id="originalImage" source="@Embed(source='assets/c2.png')"/>
</s:VGroup>
<s:VGroup>
<s:Label text="Outline Matrix Image"/>
<mx:Image id="outlineImage" source="@Embed(source='assets/c2.png')"/>
</s:VGroup>
<s:VGroup>
<s:Label text="Sharpness Matrix Image"/>
<mx:Image id="sharpnessImage" source="@Embed(source='assets/c2.png')"/>
</s:VGroup>
<s:VGroup>
<s:Label text="Brightness Matrix Image"/>
<mx:Image id="brightnessImage" source="@Embed(source='assets/c2.png')"/>
</s:VGroup>
</s:VGroup>
</s:Application>
BaseFilter 
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