window.runtime propertywindow.runtime.flash.display.BitmapData
InheritanceBitmapData Inheritance Object
Runtime Versions: AIR 1.0, Flash Player 9

The BitmapData class lets you work with the data (pixels) of a bitmap image. You can use the methods of the BitmapData class to create arbitrarily sized transparent or opaque bitmap images and manipulate them in various ways at runtime.

A BitmapData object contains an array of pixel data. This data can represent either a fully opaque bitmap or a transparent bitmap that contains alpha channel data. Either type of BitmapData object is stored as a buffer of 32-bit integers. Each 32-bit integer determines the properties of a single pixel in the bitmap.

Each 32-bit integer is a combination of four 8-bit channel values (from 0 to 255) that describe the alpha transparency and the red, green, and blue (ARGB) values of the pixel. (For ARGB values, the most significant byte represents the alpha channel value, followed by red, green, and blue.)

The four channels (alpha, red, green, and blue) are represented as numbers when you use them with the BitmapData.copyChannel() method or the DisplacementMapFilter.componentX and DisplacementMapFilter.componentY properties, and these numbers are represented by the following constants in the BitmapDataChannel class:

In the AIR runtime, the DockIcon, Icon, InteractiveIcon, and SystemTrayIcon classes each include a bitmaps property that is an array of BitmapData objects that define the bitmap images for an icon.

The maximum width and maximum height of a BitmapData object is 2880 pixels.

Calls to any method or property of a BitmapData object throw an ArgumentError error if the BitmapData object is invalid (for example, if it has height == 0 and width == 0) or it has been disposed of via dispose().

View the examples

See also

DockIcon.bitmaps
Icon.bitmaps
InteractiveIcon.bitmaps
SystemTrayIcon.bitmaps


Properties
 PropertyDefined By
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  height : int
[read-only] The height of the bitmap image in pixels.
BitmapData
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
  rect : Rectangle
[read-only] The rectangle that defines the size and location of the bitmap image.
BitmapData
  transparent : Boolean
[read-only] Defines whether the bitmap image supports per-pixel transparency.
BitmapData
  width : int
[read-only] The width of the bitmap image in pixels.
BitmapData
Public Methods
 MethodDefined By
  
BitmapData(width:int, height:int, transparent:Boolean = true, fillColor:uint = 0xFFFFFFFF)
Creates a BitmapData object with a specified width and height.
BitmapData
  
applyFilter(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, filter:BitmapFilter):void
Takes a source image and a filter object and generates the filtered image.
BitmapData
  
Returns a new BitmapData object that is a clone of the original instance with an exact copy of the contained bitmap.
BitmapData
  
colorTransform(rect:Rectangle, colorTransform:ColorTransform):void
Adjusts the color values in a specified area of a bitmap image by using a ColorTransform object.
BitmapData
  
compare(otherBitmapData:BitmapData):Object
Compares two BitmapData objects.
BitmapData
  
copyChannel(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, sourceChannel:uint, destChannel:uint):void
Transfers data from one channel of another BitmapData object or the current BitmapData object into a channel of the current BitmapData object.
BitmapData
  
copyPixels(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, alphaBitmapData:BitmapData = null, alphaPoint:Point = null, mergeAlpha:Boolean = false):void
Provides a fast routine to perform pixel manipulation between images with no stretching, rotation, or color effects.
BitmapData
  
Frees memory that is used to store the BitmapData object.
BitmapData
  
draw(source:IBitmapDrawable, matrix:Matrix = null, colorTransform:ColorTransform = null, blendMode:String = null, clipRect:Rectangle = null, smoothing:Boolean = false):void
Draws the source display object onto the bitmap image, using the Flash Player or AIR vector renderer.
BitmapData
  
fillRect(rect:Rectangle, color:uint):void
Fills a rectangular area of pixels with a specified ARGB color.
BitmapData
  
floodFill(x:int, y:int, color:uint):void
Performs a flood fill operation on an image starting at an (x, y) coordinate and filling with a certain color.
BitmapData
  
generateFilterRect(sourceRect:Rectangle, filter:BitmapFilter):Rectangle
Determines the destination rectangle that the applyFilter() method call affects, given a BitmapData object, a source rectangle, and a filter object.
BitmapData
  
getColorBoundsRect(mask:uint, color:uint, findColor:Boolean = true):Rectangle
Determines a rectangular region that either fully encloses all pixels of a specified color within the bitmap image (if the findColor parameter is set to true) or fully encloses all pixels that do not include the specified color (if the findColor parameter is set to false).
BitmapData
  
getPixel(x:int, y:int):uint
Returns an integer that represents an RGB pixel value from a BitmapData object at a specific point (x, y).
BitmapData
  
getPixel32(x:int, y:int):uint
Returns an ARGB color value that contains alpha channel data and RGB data.
BitmapData
  
Generates a byte array from a rectangular region of pixel data.
BitmapData
 Inherited
hasOwnProperty(name:String):Boolean
Indicates whether an object has a specified property defined.
Object
  
hitTest(firstPoint:Point, firstAlphaThreshold:uint, secondObject:Object, secondBitmapDataPoint:Point = null, secondAlphaThreshold:uint = 1):Boolean
Performs pixel-level hit detection between one bitmap image and a point, rectangle, or other bitmap image.
BitmapData
 Inherited
isPrototypeOf(theClass:Object):Boolean
Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.
Object
  
Locks an image so that any objects that reference the BitmapData object, such as Bitmap objects, are not updated when this BitmapData object changes.
BitmapData
  
merge(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, redMultiplier:uint, greenMultiplier:uint, blueMultiplier:uint, alphaMultiplier:uint):void
Performs per-channel blending from a source image to a destination image.
BitmapData
  
noise(randomSeed:int, low:uint = 0, high:uint = 255, channelOptions:uint = 7, grayScale:Boolean = false):void
Fills an image with pixels representing random noise.
BitmapData
  
paletteMap(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, redArray:Array = null, greenArray:Array = null, blueArray:Array = null, alphaArray:Array = null):void
Remaps the color channel values in an image that has up to four arrays of color palette data, one for each channel.
BitmapData
  
perlinNoise(baseX:Number, baseY:Number, numOctaves:uint, randomSeed:int, stitch:Boolean, fractalNoise:Boolean, channelOptions:uint = 7, grayScale:Boolean = false, offsets:Array = null):void
Generates a Perlin noise image.
BitmapData
  
pixelDissolve(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, randomSeed:int = 0, numPixels:int = 0, fillColor:uint = 0):int
Performs a pixel dissolve either from a source image to a destination image or by using the same image.
BitmapData
 Inherited
propertyIsEnumerable(name:String):Boolean
Indicates whether the specified property exists and is enumerable.
Object
  
scroll(x:int, y:int):void
Scrolls an image by a certain (x, y) pixel amount.
BitmapData
  
setPixel(x:int, y:int, color:uint):void
Sets a single pixel of a BitmapData object.
BitmapData
  
setPixel32(x:int, y:int, color:uint):void
Sets the color and alpha transparency values of a single pixel of a BitmapData object.
BitmapData
  
setPixels(rect:Rectangle, inputByteArray:ByteArray):void
Converts a byte array into a rectangular region of pixel data.
BitmapData
 Inherited
setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void
Sets the availability of a dynamic property for loop operations.
Object
  
threshold(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, operation:String, threshold:uint, color:uint = 0, mask:uint = 0xFFFFFFFF, copySource:Boolean = false):uint
Tests pixel values in an image against a specified threshold and sets pixels that pass the test to new color values.
BitmapData
 Inherited
toString():String
Returns the string representation of the specified object.
Object
  
unlock(changeRect:Rectangle = null):void
Unlocks an image so that any objects that reference the BitmapData object, such as Bitmap objects, are updated when this BitmapData object changes.
BitmapData
 Inherited
valueOf():Object
Returns the primitive value of the specified object.
Object
Property Detail
heightproperty
height:int  [read-only]
Runtime Versions: AIR 1.0, Flash Player 9

The height of the bitmap image in pixels.

rectproperty 
rect:Rectangle  [read-only]
Runtime Versions: AIR 1.0, Flash Player 9

The rectangle that defines the size and location of the bitmap image. The top and left of the rectangle are 0; the width and height are equal to the width and height in pixels of the BitmapData object.

transparentproperty 
transparent:Boolean  [read-only]
Runtime Versions: AIR 1.0, Flash Player 9

Defines whether the bitmap image supports per-pixel transparency. You can set this value only when you construct a BitmapData object by passing in true for the transparent parameter of the constructor. Then, after you create a BitmapData object, you can check whether it supports per-pixel transparency by determining if the value of the transparent property is true.

widthproperty 
width:int  [read-only]
Runtime Versions: AIR 1.0, Flash Player 9

The width of the bitmap image in pixels.

Constructor Detail
BitmapData()Constructor
function BitmapData(width:int, height:int, transparent:Boolean = true, fillColor:uint = 0xFFFFFFFF)
Runtime Versions: AIR 1.0, Flash Player 9

Creates a BitmapData object with a specified width and height. If you specify a value for the fillColor parameter, every pixel in the bitmap is set to that color.

By default, the bitmap is created as transparent, unless you pass the value false for the transparent parameter. After you create an opaque bitmap, you cannot change it to a transparent bitmap. Every pixel in an opaque bitmap uses only 24 bits of color channel information. If you define the bitmap as transparent, every pixel uses 32 bits of color channel information, including an alpha transparency channel.

The maximum width and maximum height of a BitmapData object is 2880 pixels. If you specify a width or height value that is greater than 2880, a new instance is not created.

Parameters
width:int — The width of the bitmap image in pixels.
 
height:int — The height of the bitmap image in pixels.
 
transparent:Boolean (default = true) — Specifies whether the bitmap image supports per-pixel transparency. The default value is true (transparent). To create a fully transparent bitmap, set the value of the transparent parameter to true and the value of the fillColor parameter to 0x00000000 (or to 0). Setting the transparent property to false can result in minor improvements in rendering performance.
 
fillColor:uint (default = 0xFFFFFFFF) — A 32-bit ARGB color value that you use to fill the bitmap image area. The default value is 0xFFFFFFFF (solid white).

Throws
ArgumentError — width and/or height are invalid (less than or equal to zero, greater than 2880)
Method Detail
applyFilter()method
function applyFilter(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, filter:BitmapFilter):void
Runtime Versions: AIR 1.0, Flash Player 9

Takes a source image and a filter object and generates the filtered image.

This method relies on the behavior of built-in filter objects, which determine the destination rectangle that is affected by an input source rectangle.

After a filter is applied, the resulting image can be larger than the input image. For example, if you use a BlurFilter class to blur a source rectangle of (50,50,100,100) and a destination point of (10,10), the area that changes in the destination image is larger than (10,10,60,60) because of the blurring. This happens internally during the applyFilter() call.

If the sourceRect parameter of the sourceBitmapData parameter is an interior region, such as (50,50,100,100) in a 200 x 200 image, the filter uses the source pixels outside the sourceRect parameter to generate the destination rectangle.

If the BitmapData object and the object specified as the sourceBitmapData parameter are the same object, the application uses a temporary copy of the object to perform the filter. For best performance, avoid this situation.

Parameters

sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different BitmapData object or it can refer to the current BitmapData instance.
 
sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
 
destPoint:Point — The point within the destination image (the current BitmapData instance) that corresponds to the upper-left corner of the source rectangle.
 
filter:BitmapFilter — The filter object that you use to perform the filtering operation. Each type of filter has certain requirements, as follows:
  • BlurFilter — This filter can use source and destination images that are either opaque or transparent. If the formats of the images do not match, the copy of the source image that is made during the filtering matches the format of the destination image.
  • BevelFilter, DropShadowFilter, GlowFilter, ChromeFilter — The destination image of these filters must be a transparent image. Calling DropShadowFilter or GlowFilter creates an image that contains the alpha channel data of the drop shadow or glow. It does not create the drop shadow onto the destination image. If you use any of these filters with an opaque destination image, an exception is thrown.
  • ConvolutionFilter — This filter can use source and destination images that are either opaque or transparent.
  • ColorMatrixFilter — This filter can use source and destination images that are either opaque or transparent.
  • DisplacementMapFilter — This filter can use source and destination images that are either opaque or transparent, but the source and destination image formats must be the same.


Throws
TypeError — The sourceBitmapData, sourceRect, destPoint or filter are null.
 
IllegalOperationError — The transparency of the BitmapData objects are not compatible with the filter operation.
clone()method 
function clone():BitmapData
Runtime Versions: AIR 1.0, Flash Player 9

Returns a new BitmapData object that is a clone of the original instance with an exact copy of the contained bitmap.

Returns
BitmapData — A new BitmapData object that is identical to the original.
colorTransform()method 
function colorTransform(rect:Rectangle, colorTransform:ColorTransform):void
Runtime Versions: AIR 1.0, Flash Player 9

Adjusts the color values in a specified area of a bitmap image by using a ColorTransform object. If the rectangle matches the boundaries of the bitmap image, this method transforms the color values of the entire image.

Parameters

rect:Rectangle — A Rectangle object that defines the area of the image in which the ColorTransform object is applied.
 
colorTransform:ColorTransform — A ColorTransform object that describes the color transformation values to apply.


Throws
TypeError — The rect or colorTransform are null.

See also

compare()method 
function compare(otherBitmapData:BitmapData):Object
Runtime Versions: AIR 1.0, Flash Player 9

Compares two BitmapData objects. If the two BitmapData objects have the same dimensions (width and height), the method returns a new BitmapData object, in which each pixel is the "difference" between the pixels in the two source objects:

For example, consider the following two BitmapData objects:

  var bmd1 = new air.BitmapData(50, 50, true, 0xFFFF0000);
  var bmd2 = new air.BitmapData(50, 50, true, 0xCCFFAA00);
  var diffBmpData = bmd1.compare(bmd2);
     

Note: The colors used to fill the two BitmapData objects have slightly different RGB values (0xFF0000 and 0xFFAA00). The result of the compare() method is a new BitmapData object with each pixel showing the difference in the RGB values between the two bitmaps.

Consider the following two BitmapData objects, in which the RGB colors are the same, but the alpha values are different:

  var bmd1 = new air.BitmapData(50, 50, true, 0xFFFFAA00);
  var bmd2 = new air.BitmapData(50, 50, true, 0xCCFFAA00);
  var diffBmpData = bmd1.compare(bmd2);
  

The result of the compare() method is a new BitmapData object with each pixel showing the difference in the alpha values between the two bitmaps.

If the BitmapData objects are equivalent (with the same width, height, and identical pixel values), the method returns the number 0.

If the widths of the BitmapData objects are not equal, the method returns the number -3.

If the heights of the BitmapData objects are not equal, but the widths are the same, the method returns the number -4.

The following example compares two Bitmap objects with different widths (50 and 60):

  var bmd1 = new air.BitmapData(100, 50, false, 0xFFFF0000);
  var bmd2 = new air.BitmapData(100, 60, false, 0xFFFFAA00);
  trace(bmd1.compare(bmd2)); // -4
  

Parameters

otherBitmapData:BitmapData — The BitmapData object to compare with the source BitmapData object.

Returns
Object — If the two BitmapData objects have the same dimensions (width and height), the method returns a new BitmapData object that has the difference between the two objects (see the main discussion). If the BitmapData objects are equivalent, the method returns the number 0. If the widths of the BitmapData objects are not equal, the method returns the number -3. If the heights of the BitmapData objects are not equal, the method returns the number -4.

Throws
TypeError — The otherBitmapData is null.
copyChannel()method 
function copyChannel(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, sourceChannel:uint, destChannel:uint):void
Runtime Versions: AIR 1.0, Flash Player 9

Transfers data from one channel of another BitmapData object or the current BitmapData object into a channel of the current BitmapData object. All of the data in the other channels in the destination BitmapData object are preserved.

The source channel value and destination channel value can be one of following values:

Parameters

sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different BitmapData object or it can refer to the current BitmapData object.
 
sourceRect:Rectangle — The source Rectangle object. To copy only channel data from a smaller area within the bitmap, specify a source rectangle that is smaller than the overall size of the BitmapData object.
 
destPoint:Point — The destination Point object that represents the upper-left corner of the rectangular area where the new channel data is placed. To copy only channel data from one area to a different area in the destination image, specify a point other than (0,0).
 
sourceChannel:uint — The source channel. Use a value from the BitmapDataChannel class (BitmapDataChannel.RED, BitmapDataChannel.BLUE, BitmapDataChannel.GREEN, BitmapDataChannel.ALPHA).
 
destChannel:uint — The destination channel. Use a value from the BitmapDataChannel class (BitmapDataChannel.RED, BitmapDataChannel.BLUE, BitmapDataChannel.GREEN, BitmapDataChannel.ALPHA).


Throws
TypeError — The sourceBitmapData, sourceRect or destPoint are null.

See also

copyPixels()method 
function copyPixels(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, alphaBitmapData:BitmapData = null, alphaPoint:Point = null, mergeAlpha:Boolean = false):void
Runtime Versions: AIR 1.0, Flash Player 9

Provides a fast routine to perform pixel manipulation between images with no stretching, rotation, or color effects. This method copies a rectangular area of a source image to a rectangular area of the same size at the destination point of the destination BitmapData object.

If you include the alphaBitmap and alphaPoint parameters, you can use a secondary image as an alpha source for the source image. If the source image has alpha data, both sets of alpha data are used to composite pixels from the source image to the destination image. The alphaPoint parameter is the point in the alpha image that corresponds to the upper-left corner of the source rectangle. Any pixels outside the intersection of the source image and alpha image are not copied to the destination image.

The mergeAlpha property controls whether or not the alpha channel is used when a transparent image is copied onto another transparent image. To copy pixels with the alpha channel data, set the mergeAlpha property to true. By default, the mergeAlpha property is false.

Parameters

sourceBitmapData:BitmapData — The input bitmap image from which to copy pixels. The source image can be a different BitmapData instance, or it can refer to the current BitmapData instance.
 
sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
 
destPoint:Point — The destination point that represents the upper-left corner of the rectangular area where the new pixels are placed.
 
alphaBitmapData:BitmapData (default = null) — A secondary, alpha BitmapData object source.
 
alphaPoint:Point (default = null) — The point in the alpha BitmapData object source that corresponds to the upper-left corner of the sourceRect parameter.
 
mergeAlpha:Boolean (default = false) — To use the alpha channel, set the value to true. To copy pixels with no alpha channel, set the value to false.


Throws
TypeError — The sourceBitmapData, sourceRect, destPoint are null.
dispose()method 
function dispose():void
Runtime Versions: AIR 1.0, Flash Player 9

Frees memory that is used to store the BitmapData object.

When the dispose() method is called on an image, the width and height of the image are set to 0. All subsequent calls to methods or properties of this BitmapData instance fail, and an exception is thrown.

draw()method 
function draw(source:IBitmapDrawable, matrix:Matrix = null, colorTransform:ColorTransform = null, blendMode:String = null, clipRect:Rectangle = null, smoothing:Boolean = false):void
Runtime Versions: AIR 1.0, Flash Player 9

Draws the source display object onto the bitmap image, using the AIR vector renderer. AIR vector renderer. You can specify matrix, colorTransform, blendMode, and a destination clipRect parameter to control how the rendering performs. Optionally, you can specify whether the bitmap should be smoothed when scaled (this works only if the source object is a BitmapData object).

This method directly corresponds to how objects are drawn with the standard vector renderer for objects in the authoring tool interface.

The source display object does not use any of its applied transformations for this call. It is treated as it exists in the library or file, with no matrix transform, no color transform, and no blend mode. To draw a display object (such as a movie clip) by using its own transform properties, you can copy its transform property object to the transform property of the Bitmap object that uses the BitmapData object.

This method is supported over RTMP in Adobe AIR. You can control access to streams on Flash Media Server in a server-side script. For more information, see the Client.audioSampleAccess and Client.videoSampleAccess properties in Server-Side ActionScript Language Reference for Adobe Flash Media Server.

On Windows, the draw() method cannot capture SWF content embedded in an HTML page.

The draw() method cannot capture PDF content. Nor can it capture or SWF content embedded in HTML in which the wmode attribute is set to "window".

Parameters

source:IBitmapDrawable — The display object or BitmapData object to draw to the BitmapData object. (The DisplayObject and BitmapData classes implement the IBitmapDrawable interface.)
 
matrix:Matrix (default = null) — A Matrix object used to scale, rotate, or translate the coordinates of the bitmap. If you do not want to apply a matrix transformation to the image, set this parameter to an identity matrix, created with the default new Matrix() constructor, or pass a null value.
 
colorTransform:ColorTransform (default = null) — A ColorTransform object that you use to adjust the color values of the bitmap. If no object is supplied, the bitmap image's colors are not transformed. If you must pass this parameter but you do not want to transform the image, set this parameter to a ColorTransform object created with the default new ColorTransform() constructor.
 
blendMode:String (default = null) — A string value, from the flash.display.BlendMode class, specifying the blend mode to be applied to the resulting bitmap.
 
clipRect:Rectangle (default = null) — A Rectangle object that defines the area of the source object to draw. If you do not supply this value, no clipping occurs and the entire source object is drawn.
 
smoothing:Boolean (default = false) — A Boolean value that determines whether a BitmapData object is smoothed when scaled or rotated, due to a scaling or rotation in the matrix parameter. The smoothing parameter only applies if the source parameter is a BitmapData object. With smoothing set to false, the rotated or scaled BitmapData image can appear pixelated or jagged. For example, the following two images use the same BitmapData object for the source parameter, but the smoothing parameter is set to true on the left and false on the right:

Two images: the left one with smoothing and the right one without smoothing.

Drawing a bitmap with smoothing set to true takes longer than doing so with smoothing set to false.


Throws
ArgumentError — The source parameter is not a BitmapData or DisplayObject object.
 
SecurityError — The source object and (in the case of a Sprite or MovieClip object) all of its child objects do not come from the same domain as the caller, or are not in a content that is accessible to the caller by having called the Security.allowDomain() method. This restriction does not apply to AIR content in the application security sandbox.
 
ArgumentError — The source is null or not a valid IBitmapDrawable object.

See also

fillRect()method 
function fillRect(rect:Rectangle, color:uint):void
Runtime Versions: AIR 1.0, Flash Player 9

Fills a rectangular area of pixels with a specified ARGB color.

Parameters

rect:Rectangle — The rectangular area to fill.
 
color:uint — The ARGB color value that fills the area. ARGB colors are often specified in hexadecimal format; for example, 0xFF336699.


Throws
TypeError — The rect is null.

See also

floodFill()method 
function floodFill(x:int, y:int, color:uint):void
Runtime Versions: AIR 1.0, Flash Player 9

Performs a flood fill operation on an image starting at an (x, y) coordinate and filling with a certain color. The floodFill() method is similar to the paint bucket tool in various paint programs. The color is an ARGB color that contains alpha information and color information.

Parameters

x:int — The x coordinate of the image.
 
y:int — The y coordinate of the image.
 
color:uint — The ARGB color to use as a fill.

generateFilterRect()method 
function generateFilterRect(sourceRect:Rectangle, filter:BitmapFilter):Rectangle
Runtime Versions: AIR 1.0, Flash Player 9

Determines the destination rectangle that the applyFilter() method call affects, given a BitmapData object, a source rectangle, and a filter object.

For example, a blur filter normally affects an area larger than the size of the original image. A 100 x 200 pixel image that is being filtered by a default BlurFilter instance, where blurX = blurY = 4 generates a destination rectangle of (-2,-2,104,204). The generateFilterRect() method lets you find out the size of this destination rectangle in advance so that you can size the destination image appropriately before you perform a filter operation.

Some filters clip their destination rectangle based on the source image size. For example, an inner DropShadow does not generate a larger result than its source image. In this API, the BitmapData object is used as the source bounds and not the source rect parameter.

Parameters

sourceRect:Rectangle — A rectangle defining the area of the source image to use as input.
 
filter:BitmapFilter — A filter object that you use to calculate the destination rectangle.

Returns
Rectangle — A destination rectangle computed by using an image, the sourceRect parameter, and a filter.

Throws
TypeError — The sourceRect or filter are null.
getColorBoundsRect()method 
function getColorBoundsRect(mask:uint, color:uint, findColor:Boolean = true):Rectangle
Runtime Versions: AIR 1.0, Flash Player 9

Determines a rectangular region that either fully encloses all pixels of a specified color within the bitmap image (if the findColor parameter is set to true) or fully encloses all pixels that do not include the specified color (if the findColor parameter is set to false).

For example, if you have a source image and you want to determine the rectangle of the image that contains a nonzero alpha channel, pass {mask: 0xFF000000, color: 0x00000000} as parameters. If the findColor parameter is set to true, the entire image is searched for the bounds of pixels for which (value & mask) == color (where value is the color value of the pixel). If the findColor parameter is set to false, the entire image is searched for the bounds of pixels for which (value & mask) != color (where value is the color value of the pixel). To determine white space around an image, pass {mask: 0xFFFFFFFF, color: 0xFFFFFFFF} to find the bounds of nonwhite pixels.

Parameters

mask:uint — A hexadecimal value, specifying the bits of the ARGB color to consider. The color value is combined with this hexadecimal value, by using the & (bitwise AND) operator.
 
color:uint — A hexadecimal value, specifying the ARGB color to match (if findColor is set to true) or not to match (if findColor is set to false).
 
findColor:Boolean (default = true) — If the value is set to true, returns the bounds of a color value in an image. If the value is set to false, returns the bounds of where this color doesn't exist in an image.

Returns
Rectangle — The region of the image that is the specified color.
getPixel()method 
function getPixel(x:int, y:int):uint
Runtime Versions: AIR 1.0, Flash Player 9

Returns an integer that represents an RGB pixel value from a BitmapData object at a specific point (x, y). The getPixel() method returns an unmultiplied pixel value. No alpha information is returned.

All pixels in a BitmapData object are stored as premultiplied color values. A premultiplied image pixel has the red, green, and blue color channel values already multiplied by the alpha data. For example, if the alpha value is 0, the values for the RGB channels are also 0, independent of their unmultiplied values. This loss of data can cause some problems when you perform operations. All BitmapData methods take and return unmultiplied values. The internal pixel representation is converted from premultiplied to unmultiplied before it is returned as a value. During a set operation, the pixel value is premultiplied before the raw image pixel is set.

Parameters

x:int — The x position of the pixel.
 
y:int — The y position of the pixel.

Returns
uint — A number that represents an RGB pixel value. If the (x, y) coordinates are outside the bounds of the image, the method returns 0.

See also

getPixel32()method 
function getPixel32(x:int, y:int):uint
Runtime Versions: AIR 1.0, Flash Player 9

Returns an ARGB color value that contains alpha channel data and RGB data. This method is similar to the getPixel() method, which returns an RGB color without alpha channel data.

All pixels in a BitmapData object are stored as premultiplied color values. A premultiplied image pixel has the red, green, and blue color channel values already multiplied by the alpha data. For example, if the alpha value is 0, the values for the RGB channels are also 0, independent of their unmultiplied values. This loss of data can cause some problems when you perform operations. All BitmapData methods take and return unmultiplied values. The internal pixel representation is converted from premultiplied to unmultiplied before it is returned as a value. During a set operation, the pixel value is premultiplied before the raw image pixel is set.

Parameters

x:int — The x position of the pixel.
 
y:int — The y position of the pixel.

Returns
uint — A number representing an ARGB pixel value. If the (x, y) coordinates are outside the bounds of the image, 0 is returned.

See also

getPixels()method 
function getPixels(rect:Rectangle):ByteArray
Runtime Versions: AIR 1.0, Flash Player 9

Generates a byte array from a rectangular region of pixel data. Writes an unsigned integer (a 32-bit unmultiplied pixel value) for each pixel into the byte array.

Parameters

rect:Rectangle — A rectangular area in the current BitmapData object.

Returns
ByteArray — A ByteArray representing the pixels in the given Rectangle.

Throws
TypeError — The rect is null.

See also

hitTest()method 
function hitTest(firstPoint:Point, firstAlphaThreshold:uint, secondObject:Object, secondBitmapDataPoint:Point = null, secondAlphaThreshold:uint = 1):Boolean
Runtime Versions: AIR 1.0, Flash Player 9

Performs pixel-level hit detection between one bitmap image and a point, rectangle, or other bitmap image. No stretching, rotation, or other transformation of either object is considered when the hit test is performed.

If an image is an opaque image, it is considered a fully opaque rectangle for this method. Both images must be transparent images to perform pixel-level hit testing that considers transparency. When you are testing two transparent images, the alpha threshold parameters control what alpha channel values, from 0 to 255, are considered opaque.

Parameters

firstPoint:Point — A position of the upper-left corner of the BitmapData image in an arbitrary coordinate space. The same coordinate space is used in defining the secondBitmapPoint parameter.
 
firstAlphaThreshold:uint — The highest alpha channel value that is considered opaque for this hit test.
 
secondObject:Object — A Rectangle, Point, Bitmap, or BitmapData object.
 
secondBitmapDataPoint:Point (default = null) — A point that defines a pixel location in the second BitmapData object. Use this parameter only when the value of secondObject is a BitmapData object.
 
secondAlphaThreshold:uint (default = 1) — The highest alpha channel value that is considered opaque in the second BitmapData object. Use this parameter only when the value of secondObject is a BitmapData object and both BitmapData objects are transparent.

Returns
Boolean — A value of true if a hit occurs; otherwise, false.

Throws
ArgumentError — The secondObject parameter is not a Point, Rectangle, Bitmap, or BitmapData object.
 
TypeError — The firstPoint is null.
lock()method 
function lock():void
Runtime Versions: AIR 1.0, Flash Player 9

Locks an image so that any objects that reference the BitmapData object, such as Bitmap objects, are not updated when this BitmapData object changes. To improve performance, use this method along with the unlock() method before and after numerous calls to the setPixel() or setPixel32() method.

See also

merge()method 
function merge(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, redMultiplier:uint, greenMultiplier:uint, blueMultiplier:uint, alphaMultiplier:uint):void
Runtime Versions: AIR 1.0, Flash Player 9

Performs per-channel blending from a source image to a destination image. For each channel and each pixel, a new value is computed based on the channel values of the source and destination pixels. For example, in the red channel, the new value is computed as follows (where redSrc is the red channel value for a pixel in the source image and redDest is the red channel value at the corresponding pixel of the destination image):

new redDest = [(redSrc * redMultiplier) + (redDest * (256 - redMultiplier))] / 256;

The redMultiplier, greenMultiplier, blueMultiplier, and alphaMultiplier values are the multipliers used for each color channel. Use a hexadecimal value ranging from 0 to 0x100 (256) where 0 specifies the full value from the destination is used in the result, 0x100 specifies the full value from the source is used, and numbers in between specify a blend is used (such as 0x80 for 50%).

Parameters

sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different BitmapData object, or it can refer to the current BitmapData object.
 
sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
 
destPoint:Point — The point within the destination image (the current BitmapData instance) that corresponds to the upper-left corner of the source rectangle.
 
redMultiplier:uint — A hexadecimal uint value by which to multiply the red channel value.
 
greenMultiplier:uint — A hexadecimal uint value by which to multiply the green channel value.
 
blueMultiplier:uint — A hexadecimal uint value by which to multiply the blue channel value.
 
alphaMultiplier:uint — A hexadecimal uint value by which to multiply the alpha transparency value.


Throws
TypeError — The sourceBitmapData, sourceRect or destPoint are null.
noise()method 
function noise(randomSeed:int, low:uint = 0, high:uint = 255, channelOptions:uint = 7, grayScale:Boolean = false):void
Runtime Versions: AIR 1.0, Flash Player 9

Fills an image with pixels representing random noise.

Parameters

randomSeed:int — The random seed number to use. If you keep all other parameters the same, you can generate different pseudo-random results by varying the random seed value. The noise function is a mapping function, not a true random-number generation function, so it creates the same results each time from the same random seed.
 
low:uint (default = 0) — The lowest value to generate for each channel (0 to 255).
 
high:uint (default = 255) — The highest value to generate for each channel (0 to 255).
 
channelOptions:uint (default = 7) — A number that can be a combination of any of the four color channel values (BitmapDataChannel.RED, BitmapDataChannel.BLUE, BitmapDataChannel.GREEN, and BitmapDataChannel.ALPHA). You can use the logical OR operator (|) to combine channel values.
 
grayScale:Boolean (default = false) — A Boolean value. If the value is true, a grayscale image is created by setting all of the color channels to the same value. The alpha channel selection is not affected by setting this parameter to true.

paletteMap()method 
function paletteMap(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, redArray:Array = null, greenArray:Array = null, blueArray:Array = null, alphaArray:Array = null):void
Runtime Versions: AIR 1.0, Flash Player 9

Remaps the color channel values in an image that has up to four arrays of color palette data, one for each channel.

AIR uses the following steps to generate the resulting image:

  1. After the red, green, blue, and alpha values are computed, they are added together using standard 32-bit-integer arithmetic.
  2. The red, green, blue, and alpha channel values of each pixel are extracted into separate 0 to 255 values. These values are used to look up new color values in the appropriate array: redArray, greenArray, blueArray, and alphaArray. Each of these four arrays should contain 256 values.
  3. After all four of the new channel values are retrieved, they are combined into a standard ARGB value that is applied to the pixel.

Cross-channel effects can be supported with this method. Each input array can contain full 32-bit values, and no shifting occurs when the values are added together. This routine does not support per-channel clamping.

If no array is specified for a channel, the color channel is copied from the source image to the destination image.

You can use this method for a variety of effects such as general palette mapping (taking one channel and converting it to a false color image). You can also use this method for a variety of advanced color manipulation algorithms, such as gamma, curves, levels, and quantizing.

Parameters

sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different BitmapData object, or it can refer to the current BitmapData instance.
 
sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
 
destPoint:Point — The point within the destination image (the current BitmapData object) that corresponds to the upper-left corner of the source rectangle.
 
redArray:Array (default = null) — If redArray is not null, red = redArray[source red value] else red = source rect value.
 
greenArray:Array (default = null) — If greenArray is not null, green = greenArray[source green value] else green = source green value.
 
blueArray:Array (default = null) — If blueArray is not null, blue = blueArray[source blue value] else blue = source blue value.
 
alphaArray:Array (default = null) — If alphaArray is not null, alpha = alphaArray[source alpha value] else alpha = source alpha value.


Throws
TypeError — The sourceBitmapData, sourceRect or destPoint are null.
perlinNoise()method 
function perlinNoise(baseX:Number, baseY:Number, numOctaves:uint, randomSeed:int, stitch:Boolean, fractalNoise:Boolean, channelOptions:uint = 7, grayScale:Boolean = false, offsets:Array = null):void
Runtime Versions: AIR 1.0, Flash Player 9

Generates a Perlin noise image.

The Perlin noise generation algorithm interpolates and combines individual random noise functions (called octaves) into a single function that generates more natural-seeming random noise. Like musical octaves, each octave function is twice the frequency of the one before it. Perlin noise has been described as a "fractal sum of noise" because it combines multiple sets of noise data with different levels of detail.

You can use Perlin noise functions to simulate natural phenomena and landscapes, such as wood grain, clouds, and mountain ranges. In most cases, the output of a Perlin noise function is not displayed directly but is used to enhance other images and give them pseudo-random variations.

Simple digital random noise functions often produce images with harsh, contrasting points. This kind of harsh contrast is not often found in nature. The Perlin noise algorithm blends multiple noise functions that operate at different levels of detail. This algorithm results in smaller variations among neighboring pixel values.

Note: The Perlin noise algorithm is named for Ken Perlin, who developed it after generating computer graphics for the 1982 film Tron. Perlin received an Academy Award for Technical Achievement for the Perlin noise function in 1997.

Parameters

baseX:Number — Frequency to use in the x direction. For example, to generate a noise that is sized for a 64 x 128 image, pass 64 for the baseX value.
 
baseY:Number — Frequency to use in the y direction. For example, to generate a noise that is sized for a 64 x 128 image, pass 128 for the baseY value.
 
numOctaves:uint — Number of octaves or individual noise functions to combine to create this noise. Larger numbers of octaves create images with greater detail. Larger numbers of octaves also require more processing time.
 
randomSeed:int — The random seed number to use. If you keep all other parameters the same, you can generate different pseudo-random results by varying the random seed value. The Perlin noise function is a mapping function, not a true random-number generation function, so it creates the same results each time from the same random seed.
 
stitch:Boolean — A Boolean value. If the value is true, the method attempts to smooth the transition edges of the image to create seamless textures for tiling as a bitmap fill.
 
fractalNoise:Boolean — A Boolean value. If the value is true, the method generates fractal noise; otherwise, it generates turbulence. An image with turbulence has visible discontinuities in the gradient that can make it better approximate sharper visual effects like flames and ocean waves.
 
channelOptions:uint (default = 7) — A number that can be a combination of any of the four color channel values (BitmapDataChannel.RED, BitmapDataChannel.BLUE, BitmapDataChannel.GREEN, and BitmapDataChannel.ALPHA). You can use the logical OR operator (|) to combine channel values.
 
grayScale:Boolean (default = false) — A Boolean value. If the value is true, a grayscale image is created by setting each of the red, green, and blue color channels to identical values. The alpha channel value is not affected if this value is set to true.
 
offsets:Array (default = null) — An array of points that correspond to x and y offsets for each octave. By manipulating the offset values you can smoothly scroll the layers of a perlinNoise image. Each point in the offset array affects a specific octave noise function.

pixelDissolve()method 
function pixelDissolve(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, randomSeed:int = 0, numPixels:int = 0, fillColor:uint = 0):int
Runtime Versions: AIR 1.0, Flash Player 9

Performs a pixel dissolve either from a source image to a destination image or by using the same image. AIR uses a randomSeed value to generate a random pixel dissolve. The return value of the function must be passed in on subsequent calls to continue the pixel dissolve until it is finished.

If the source image does not equal the destination image, pixels are copied from the source to the destination by using all of the properties. This process allows dissolving from a blank image into a fully populated image.

If the source and destination images are equal, pixels are filled with the color parameter. This process allows dissolving away from a fully populated image. In this mode, the destination point parameter is ignored.

Parameters

sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different BitmapData object, or it can refer to the current BitmapData instance.
 
sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
 
destPoint:Point — The point within the destination image (the current BitmapData instance) that corresponds to the upper-left corner of the source rectangle.
 
randomSeed:int (default = 0) — The random seed to use to start the pixel dissolve.
 
numPixels:int (default = 0) — The default is 1/30 of the source area (width x height).
 
fillColor:uint (default = 0) — An ARGB color value that you use to fill pixels whose source value equals its destination value.

Returns
int — The new random seed value to use for subsequent calls.

Throws
TypeError — The sourceBitmapData, sourceRect or destPoint are null.
 
TypeError — The numPixels value is negative
scroll()method 
function scroll(x:int, y:int):void
Runtime Versions: AIR 1.0, Flash Player 9

Scrolls an image by a certain (x, y) pixel amount. Edge regions outside the scrolling area are left unchanged.

Parameters

x:int — The amount by which to scroll horizontally.
 
y:int — The amount by which to scroll vertically.

setPixel()method 
function setPixel(x:int, y:int, color:uint):void
Runtime Versions: AIR 1.0, Flash Player 9

Sets a single pixel of a BitmapData object. The current alpha channel value of the image pixel is preserved during this operation. The value of the RGB color parameter is treated as an unmultiplied color value.

Note: To increase performance, when you use the setPixel() or setPixel32() method repeatedly, call the lock() method before you call the setPixel() or setPixel32() method, and then call the unlock() method when you have made all pixel changes. This process prevents objects that reference this BitmapData instance from updating until you finish making the pixel changes.

Parameters

x:int — The x position of the pixel whose value changes.
 
y:int — The y position of the pixel whose value changes.
 
color:uint — The resulting RGB color for the pixel.

See also

setPixel32()method 
function setPixel32(x:int, y:int, color:uint):void
Runtime Versions: AIR 1.0, Flash Player 9

Sets the color and alpha transparency values of a single pixel of a BitmapData object. This method is similar to the setPixel() method; the main difference is that the setPixel32() method takes an ARGB color value that contains alpha channel information.

All pixels in a BitmapData object are stored as premultiplied color values. A premultiplied image pixel has the red, green, and blue color channel values already multiplied by the alpha data. For example, if the alpha value is 0, the values for the RGB channels are also 0, independent of their unmultiplied values. This loss of data can cause some problems when you perform operations. All BitmapData methods take and return unmultiplied values. The internal pixel representation is converted from premultiplied to unmultiplied before it is returned as a value. During a set operation, the pixel value is premultiplied before the raw image pixel is set.

Note: To increase performance, when you use the setPixel() or setPixel32() method repeatedly, call the lock() method before you call the setPixel() or setPixel32() method, and then call the unlock() method when you have made all pixel changes. This process prevents objects that reference this BitmapData instance from updating until you finish making the pixel changes.

Parameters

x:int — The x position of the pixel whose value changes.
 
y:int — The y position of the pixel whose value changes.
 
color:uint — The resulting ARGB color for the pixel. If the bitmap is opaque (not transparent), the alpha transparency portion of this color value is ignored.

See also

setPixels()method 
function setPixels(rect:Rectangle, inputByteArray:ByteArray):void
Runtime Versions: AIR 1.0, Flash Player 9

Converts a byte array into a rectangular region of pixel data. For each pixel, the ByteArray.readUnsignedInt() method is called and the return value is written into the pixel. If the byte array ends before the full rectangle is written, the function returns. The data in the byte array is expected to be 32-bit ARGB pixel values. No seeking is performed on the byte array before or after the pixels are read.

Parameters

rect:Rectangle — Specifies the rectangular region of the BitmapData object.
 
inputByteArray:ByteArray — A ByteArray object that consists of 32-bit unmultiplied pixel values to be used in the rectangular region.


Throws
EOFError — The inputByteArray object does not include enough data to fill the area of the rect rectangle. The method fills as many pixels as possible before throwing the exception.
 
TypeError — The rect or inputByteArray are null.

See also

threshold()method 
function threshold(sourceBitmapData:BitmapData, sourceRect:Rectangle, destPoint:Point, operation:String, threshold:uint, color:uint = 0, mask:uint = 0xFFFFFFFF, copySource:Boolean = false):uint
Runtime Versions: AIR 1.0, Flash Player 9

Tests pixel values in an image against a specified threshold and sets pixels that pass the test to new color values. Using the threshold() method, you can isolate and replace color ranges in an image and perform other logical operations on image pixels.

The threshold() method's test logic is as follows:

  1. If ((pixelValue & mask) operation (threshold & mask)), then set the pixel to color;
  2. Otherwise, if copySource == true, then set the pixel to corresponding pixel value from sourceBitmap.

The operation parameter specifies the comparison operator to use for the threshold test. For example, by using "==" as the operation parameter, you can isolate a specific color value in an image. Or by using {operation: "<", mask: 0xFF000000, threshold: 0x7F000000, color: 0x00000000}, you can set all destination pixels to be fully transparent when the source image pixel's alpha is less than 0x7F. You can use this technique for animated transitions and other effects.

Parameters

sourceBitmapData:BitmapData — The input bitmap image to use. The source image can be a different BitmapData object or it can refer to the current BitmapData instance.
 
sourceRect:Rectangle — A rectangle that defines the area of the source image to use as input.
 
destPoint:Point — The point within the destination image (the current BitmapData instance) that corresponds to the upper-left corner of the source rectangle.
 
operation:String — One of the following comparison operators, passed as a String: "<", "<=", ">", ">=", "==", "!="
 
threshold:uint — The value that each pixel is tested against to see if it meets or exceeds the threshhold.
 
color:uint (default = 0) — The color value that a pixel is set to if the threshold test succeeds. The default value is 0x00000000.
 
mask:uint (default = 0xFFFFFFFF) — The mask to use to isolate a color component.
 
copySource:Boolean (default = false) — If the value is true, pixel values from the source image are copied to the destination when the threshold test fails. If the value is false, the source image is not copied when the threshold test fails.

Returns
uint — The number of pixels that were changed.

Throws
TypeError — The sourceBitmapData, sourceRect destPoint or operation are null.
 
ArgumentError — The operation string is not a valid operation
unlock()method 
function unlock(changeRect:Rectangle = null):void
Runtime Versions: AIR 1.0, Flash Player 9

Unlocks an image so that any objects that reference the BitmapData object, such as Bitmap objects, are updated when this BitmapData object changes. To improve performance, use this method along with the lock() method before and after numerous calls to the setPixel() or setPixel32() method.

Parameters

changeRect:Rectangle (default = null) — The area of the BitmapData object that has changed. If you do not specify a value for this parameter, the entire area of the BitmapData object is considered changed. This parameter requires Flash Player version 9.0.115.0 or later.

See also

Examples
BitmapDataExample.as

BitmapDataExample2.as

The following example uses the Loader class to load a PNG file and use the image in the application's system icon.

Note: To test this example, do the following:

  1. Add the AIRAliases.js file to the project directory.
  2. Add an 128x128 pixel PNG image file named AIRApp_128.png file to an icons subdirectory of the project directory.
  3. Create an application descriptor file for the project, and test the project using ADL.



<html>
    <head>
      <script src="AIRAliases.js" />
      <script>
        function init() {
            var loader = new air.Loader(); // new runtime.flash.display.Loader();
            loader.contentLoaderInfo.addEventListener(air.Event.COMPLETE, imgLoaded)
            
            var request = new air.URLRequest("icons/AIRApp_128.png");
            loader.load(request);
        }

        
        function imgLoaded(event)
        {
            var image = air.Bitmap(loader.content);
            air.NativeApplication.nativeApplication.icon.bitmaps = [image.bitmapData];
        }
    </script>
    </head>
    <body onload='init()'>
    </body>
</html>