Package | flash.filters |
Class | public class ConvolutionFilter |
Inheritance | ConvolutionFilter BitmapFilter Object |
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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 thefilters
property of an object does not modify the object, and you can remove the filter by clearing thefilters
property. - To apply filters to BitmapData objects, use the
BitmapData.applyFilter()
method. CallingapplyFilter()
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.) In Flash Player 9 and earlier and AIR 1.1 and earlier, the limitation is 2,880 pixels in height and 2,880 pixels in width. 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.
See also
flash.display.DisplayObject.filters
flash.display.DisplayObject.cacheAsBitmap
matrix
Property | Defined By | ||
---|---|---|---|
alpha : Number
The alpha transparency value of the substitute color. | ConvolutionFilter | ||
bias : Number
The amount of bias to add to the result of the matrix transformation. | ConvolutionFilter | ||
clamp : Boolean
Indicates whether the image should be clamped. | ConvolutionFilter | ||
color : uint
The hexadecimal color to substitute for pixels that are off the source image. | ConvolutionFilter | ||
constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | ||
divisor : Number
The divisor used during matrix transformation. | ConvolutionFilter | ||
matrix : Array
An array of values used for matrix transformation. | ConvolutionFilter | ||
matrixX : Number
The x dimension of the matrix (the number of columns in the matrix). | ConvolutionFilter | ||
matrixY : Number
The y dimension of the matrix (the number of rows in the matrix). | ConvolutionFilter | ||
preserveAlpha : Boolean
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. | ConvolutionFilter | ||
prototype : Object [static]
A reference to the prototype object of a class or function object. | Object |
Method | Defined By | ||
---|---|---|---|
ConvolutionFilter(matrixX:Number = 0, matrixY:Number = 0, matrix:Array = null, divisor:Number = 1.0, bias:Number = 0.0, preserveAlpha:Boolean = true, clamp:Boolean = true, color:uint = 0, alpha:Number = 0.0)
Initializes a ConvolutionFilter instance with the specified parameters. | ConvolutionFilter | ||
[override]
Returns a copy of this filter object. | ConvolutionFilter | ||
Indicates whether an object has a specified property defined. | Object | ||
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | ||
Indicates whether the specified property exists and is enumerable. | Object | ||
Sets the availability of a dynamic property for loop operations. | Object | ||
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | ||
Returns the string representation of the specified object. | Object | ||
Returns the primitive value of the specified object. | Object |
alpha | property |
alpha:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The alpha transparency value of the substitute color. Valid values are 0 to 1.0. The default is 0. For example, .25 sets a transparency value of 25%.
Implementation
public function get alpha():Number
public function set alpha(value:Number):void
bias | property |
bias:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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 is true
.
Implementation
public function get clamp():Boolean
public function set clamp(value:Boolean):void
Example ( How to use this example )
BitmapData
class, one of which is half the size of the other.
When the example first loads, the larger box is drawn inside mc
using the attachBitmap()
.
When mc
is clicked and the applyFilter()
method is called, the largeBox
instance of BitmapData
is redrawn with smallBox
as a source bitmap.
Since applyFilter()
draws smallBox
over a Rectangle
whose width and height is specified as those of largeBox
, the source bitmap is smaller than the drawing area.
The clamp
property of ConvolutionFilter
in this case is set to false
and the area which is not covered by the source bitmap, smallBox
, is a solid red as determined by the clampColor
and clampAlpha
variables.
package { import flash.display.Sprite; import flash.display.BitmapData; import flash.filters.ConvolutionFilter; import flash.text.TextField; import flash.geom.Rectangle; import flash.geom.Point; public class ConvolutionClampExample extends Sprite { // Variables that affect clamping: var clamp:Boolean = false; var clampColor:Number = 0xFF0000; var clampAlpha:Number = 1; // For illustration, keep other ConvolutionFilter variables neutral: var bias:Number = 0; var preserveAlpha:Boolean = false; // Also, construct a neutral matrix var matrixCols:Number = 3; var matrixRows:Number = 3; var matrix:Array = [ 1,1,1, 1,1,1, 1,1,1 ]; var filter:ConvolutionFilter = new ConvolutionFilter(matrixCols, matrixRows, matrix, matrix.length, bias, preserveAlpha, clamp, clampColor, clampAlpha); var largeBoxWidth:Number = 100; var largeBoxHeight:Number = 100; var largeBox:BitmapData = new BitmapData(largeBoxWidth, largeBoxWidth, true, 0xCC00FF00); var smallBoxWidth:Number = largeBoxWidth / 2; var smallBoxHeight:Number = largeBoxHeight / 2; var smallBox:BitmapData = new BitmapData(smallBoxWidth, smallBoxWidth, true, 0xCC0000FF); var mc:MovieClip = this.createEmptyMovieClip("mc", this.getNextHighestDepth()); mc.attachBitmap(largeBox, this.getNextHighestDepth()); mc.onPress = function() { largeBox.applyFilter(smallBox, new Rectangle(0,0, largeBoxWidth, largeBoxHeight), new Point(0,0), filter); } } }
color | property |
color:uint
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The hexadecimal color to substitute for pixels that are off the source image. It is an RGB value with no alpha component. The default is 0.
Implementation
public function get color():uint
public function set color(value:uint):void
divisor | property |
divisor:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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.
Implementation
public function get divisor():Number
public function set divisor(value:Number):void
matrix | property |
matrix:Array
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
An array of values used for matrix transformation. The number of items
in the array must equal matrixX * matrixY
.
A matrix convolution is based on an n x m matrix, which describes how a given pixel value in the input image is combined with its neighboring pixel values to produce a resulting pixel value. Each result pixel is determined by applying the matrix to the corresponding source pixel and its neighboring pixels.
For a 3 x 3 matrix convolution, the following formula is used for each independent color channel:
dst (x, y) = ((src (x-1, y-1) * a0 + src(x, y-1) * a1....
src(x, y+1) * a7 + src (x+1,y+1) * a8) / divisor) + bias
Certain filter specifications perform faster when run by a processor that offers SSE (Streaming SIMD Extensions). The following are criteria for faster convolution operations:
- The filter must be a 3x3 filter.
- All the filter terms must be integers between -127 and +127.
- The sum of all the filter terms must not have an absolute value greater than 127.
- If any filter term is negative, the divisor must be between 2.00001 and 256.
- If all filter terms are positive, the divisor must be between 1.1 and 256.
- The bias must be an integer.
Note: If you create a ConvolutionFilter instance using the
constructor without parameters, the order you assign values to matrix properties affects
the behavior of the filter. In the following case, the matrix array is assigned while the
matrixX
and matrixY
properties are still set to 0
(the default value):
public var myfilter:ConvolutionFilter = new ConvolutionFilter(); myfilter.matrix = [0, 0, 0, 0, 1, 0, 0, 0, 0]; myfilter.matrixX = 3; myfilter.matrixY = 3;
In the following case, the matrix array is assigned while the matrixX
and matrixY
properties are set to 3
:
public var myfilter:ConvolutionFilter = new ConvolutionFilter(); myfilter.matrixX = 3; myfilter.matrixY = 3; myfilter.matrix = [0, 0, 0, 0, 1, 0, 0, 0, 0];
Implementation
public function get matrix():Array
public function set matrix(value:Array):void
Throws
TypeError — The Array is null when being set
|
matrixX | property |
matrixX:Number
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The x dimension of the matrix (the number of columns 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 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
The y dimension of the matrix (the number of rows 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 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
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
ConvolutionFilter | () | Constructor |
public function ConvolutionFilter(matrixX:Number = 0, matrixY:Number = 0, matrix:Array = null, divisor:Number = 1.0, bias:Number = 0.0, preserveAlpha:Boolean = true, clamp:Boolean = true, color:uint = 0, alpha:Number = 0.0)
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
Initializes a ConvolutionFilter instance with the specified parameters.
ParametersmatrixX: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.
|
clone | () | method |
override public function clone():BitmapFilter
Language Version: | ActionScript 3.0 |
Runtime Versions: | Flash Player 9, AIR 1.0 |
Returns a copy of this filter object.
ReturnsBitmapFilter — BitmapFilter A new ConvolutionFilter instance with all the same properties as the original
ConvolutionMatrixFilter instance.
|
buildChild()
four times to load and display four instances of the image.
Each call to buildChild()
takes as an argument a function that applies
no filter to the first instance and a different convolution filter to each
subsequent instance.
The buildChild()
function creates a new Loader object named
loader
. For each call to buildChild()
,
attach an event listener to the Loader object to listen for complete
events,
which are handled by the function passed to buildChild()
.
The applyBrightness()
, applySharpness()
, and applyOutline()
functions use different values for the matrix
array to achieve different
ConvolutionFilter effects.
Note: For best results, use an image approximately 80 pixels in width.
The name and location of the image file should match the value you pass to the
url
property. For example, the value passed to url
in the example
points to an image file named "Image.jpg" that is in the same directory as your SWF file.
package { import flash.display.DisplayObject; import flash.display.Loader; import flash.display.Sprite; import flash.events.*; import flash.filters.BitmapFilter; import flash.filters.ConvolutionFilter; import flash.net.URLRequest; import flash.text.TextField; import flash.text.TextFieldAutoSize; public class ConvolutionFilterExample extends Sprite { private var size:uint = 140; private var url:String = "Image.jpg"; public function ConvolutionFilterExample() { buildChild(applyNothing); buildChild(applyBrightness); buildChild(applySharpness); buildChild(applyOutline); } private function buildChild(loadHandler:Function):void { var loader:Loader = new Loader(); loader.x = numChildren * size; loader.y = size; loader.contentLoaderInfo.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler); if(loadHandler != null) { loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loadHandler); } var request:URLRequest = new URLRequest(url); loader.load(request); addChild(loader); } private function applyNothing(event:Event):void { var child:DisplayObject = DisplayObject(event.target.loader); applyLabel(child, "no filter"); } private function applyBrightness(event:Event):void { var child:DisplayObject = DisplayObject(event.target.loader); var matrix:Array = [5, 5, 5, 5, 0, 5, 5, 5, 5]; applyFilter(child, matrix); applyLabel(child, "brightness"); } private function applySharpness(event:Event):void { var child:DisplayObject = DisplayObject(event.target.loader); var matrix:Array = [0, -1, 0, -1, 20, -1, 0, -1, 0]; applyFilter(child, matrix); applyLabel(child, "sharpness"); } private function applyOutline(event:Event):void { var child:DisplayObject = DisplayObject(event.target.loader); var matrix:Array = [-30, 30, 0, -30, 30, 0, -30, 30, 0]; applyFilter(child, matrix); applyLabel(child, "outline"); } private function applyFilter(child:DisplayObject, matrix:Array):void { var matrixX:Number = 3; var matrixY:Number = 3; var divisor:Number = 9; var filter:BitmapFilter = new ConvolutionFilter(matrixX, matrixY, matrix, divisor); var filters:Array = new Array(); filters.push(filter); child.filters = filters; } private function applyLabel(child:DisplayObject, label:String):void { var tf:TextField = new TextField(); tf.x = child.x; tf.y = child.height; tf.autoSize = TextFieldAutoSize.LEFT; tf.text = label; addChild(tf); } private function ioErrorHandler(event:IOErrorEvent):void { trace("Unable to load image: " + url); } } }
Fri Mar 19 2010, 02:45 AM -07:00