ActionScript® 3.0 Reference for the Adobe® Flash® Platform
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flash.filters 

ColorMatrixFilter  - AS3

Packageflash.filters
Classpublic final class ColorMatrixFilter
InheritanceColorMatrixFilter Inheritance BitmapFilter Inheritance Object

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9

The ColorMatrixFilter class lets you apply a 4 x 5 matrix transformation on the RGBA color and alpha values of every pixel in the input image to produce a result with a new set of RGBA color and alpha values. It allows saturation changes, hue rotation, luminance to alpha, and various other effects. 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.

Note: For RGBA values, the most significant byte represents the red channel value, followed by green, blue, and then alpha.

To create a new color matrix filter, use the syntax new ColorMatrixFilter(). 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 cacheAsBitmap property of the display object is set to true. If you remove 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 reaches the maximum dimensions.

View the examples

Related API Elements



Public Properties
 PropertyDefined By
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  matrix : Array
An array of 20 items for 4 x 5 color transform.
ColorMatrixFilter
Public Methods
 MethodDefined By
  
ColorMatrixFilter(matrix:Array = null)
Initializes a new ColorMatrixFilter instance with the specified parameters.
ColorMatrixFilter
  
[override] Returns a copy of this filter object.
ColorMatrixFilter
 Inherited
Indicates whether an object has a specified property defined.
Object
 Inherited
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
 Inherited
Indicates whether the specified property exists and is enumerable.
Object
 Inherited
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Returns the string representation of this object, formatted according to locale-specific conventions.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
Returns the primitive value of the specified object.
Object
Property Detail

matrix

property
matrix:Array

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9

An array of 20 items for 4 x 5 color transform. The matrix property cannot be changed by directly modifying its value (for example, myFilter.matrix[2] = 1;). Instead, you must get a reference to the array, make the change to the reference, and reset the value.

The color matrix filter separates each source pixel into its red, green, blue, and alpha components as srcR, srcG, srcB, srcA. To calculate the result of each of the four channels, the value of each pixel in the image is multiplied by the values in the transformation matrix. An offset, between -255 and 255, can optionally be added to each result (the fifth item in each row of the matrix). The filter combines each color component back into a single pixel and writes out the result. In the following formula, a[0] through a[19] correspond to entries 0 through 19 in the 20-item array that is passed to the matrix property:

	redResult   = (a[0]  * srcR) + (a[1]  * srcG) + (a[2]  * srcB) + (a[3]  * srcA) + a[4]
	greenResult = (a[5]  * srcR) + (a[6]  * srcG) + (a[7]  * srcB) + (a[8]  * srcA) + a[9]
	blueResult  = (a[10] * srcR) + (a[11] * srcG) + (a[12] * srcB) + (a[13] * srcA) + a[14]
	alphaResult = (a[15] * srcR) + (a[16] * srcG) + (a[17] * srcB) + (a[18] * srcA) + a[19]
	

For each color value in the array, a value of 1 is equal to 100% of that channel being sent to the output, preserving the value of the color channel.

The calculations are performed on unmultiplied color values. If the input graphic consists of premultiplied color values, those values are automatically converted into unmultiplied color values for this operation.

Two optimized modes are available:

Alpha only. When you pass to the filter a matrix that adjusts only the alpha component, as shown here, the filter optimizes its performance:

	    1 0 0 0 0
	    0 1 0 0 0
	    0 0 1 0 0
	    0 0 0 N 0  (where N is between 0.0 and 1.0)
	

Faster version. Available only with SSE/AltiVec accelerator-enabled processors, such as Intel® Pentium® 3 and later and Apple® G4 and later. The accelerator is used when the multiplier terms are in the range -15.99 to 15.99 and the adder terms a[4], a[9], a[14], and a[19] are in the range -8000 to 8000.



Implementation
    public function get matrix():Array
    public function set matrix(value:Array):void

Throws
TypeError — The Array is null when being set
Constructor Detail

ColorMatrixFilter

()Constructor
public function ColorMatrixFilter(matrix:Array = null)

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9

Initializes a new ColorMatrixFilter instance with the specified parameters.

Parameters
matrix:Array (default = null) — An array of 20 items arranged as a 4 x 5 matrix.
Method Detail

clone

()method
override public function clone():BitmapFilter

Language Version: ActionScript 3.0
Runtime Versions: AIR 1.0, Flash Player 9

Returns a copy of this filter object.

Returns
BitmapFilter — A new ColorMatrixFilter instance with all of the same properties as the original one.
ColorMatrixFilterExample.as

The following example applies different color matrix filters to an image file. The filter constructor calls buildChild() four times to load and display four instances of the image. The first call to buildChild() takes null as an argument, applying no filter to the first instance. Each subsequent call to buildChild() takes as an argument a function that applies a different color matrix filter to each subsequent instance of the image.

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 applyRed(), applyGreen(), and applyBlue() functions use different values for the matrix array to achieve different 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.Event;
    import flash.events.IOErrorEvent;
    import flash.filters.ColorMatrixFilter;
    import flash.net.URLRequest;

    public class ColorMatrixFilterExample extends Sprite {
        private var size:uint  = 140;
        private var url:String = "Image.jpg";

        public function ColorMatrixFilterExample() {
            buildChild(null);
            buildChild(applyRed);
            buildChild(applyGreen);
            buildChild(applyBlue);
        }

        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 applyRed(event:Event):void {
            var child:DisplayObject = DisplayObject(event.target.loader);
            var matrix:Array = new Array();
            matrix = matrix.concat([1, 0, 0, 0, 0]); // red
            matrix = matrix.concat([0, 0, 0, 0, 0]); // green
            matrix = matrix.concat([0, 0, 0, 0, 0]); // blue
            matrix = matrix.concat([0, 0, 0, 1, 0]); // alpha

            applyFilter(child, matrix);
        }

        private function applyGreen(event:Event):void {
            var child:DisplayObject = DisplayObject(event.target.loader);
            var matrix:Array = new Array();
            matrix = matrix.concat([0, 0, 0, 0, 0]); // red
            matrix = matrix.concat([0, 1, 0, 0, 0]); // green
            matrix = matrix.concat([0, 0, 0, 0, 0]); // blue
            matrix = matrix.concat([0, 0, 0, 1, 0]); // alpha

            applyFilter(child, matrix);
        }

        private function applyBlue(event:Event):void {
            var child:DisplayObject = DisplayObject(event.target.loader);
            var matrix:Array = new Array();
            matrix = matrix.concat([0, 0, 0, 0, 0]); // red
            matrix = matrix.concat([0, 0, 0, 0, 0]); // green
            matrix = matrix.concat([0, 0, 1, 0, 0]); // blue
            matrix = matrix.concat([0, 0, 0, 1, 0]); // alpha

            applyFilter(child, matrix);
        }

        private function applyFilter(child:DisplayObject, matrix:Array):void {
            var filter:ColorMatrixFilter = new ColorMatrixFilter(matrix);
            var filters:Array = new Array();
            filters.push(filter);
            child.filters = filters;
        }
        
        private function ioErrorHandler(event:IOErrorEvent):void {
            trace("Unable to load image: " + url);
        }
    }
}