mx.graphics.codec.JPEGEncoder - Adobe® Flex® 4 Language Reference (Flex 4)

Package	mx.graphics.codec
Class	public class JPEGEncoder
Inheritance	JPEGEncoder Object
Implements	IImageEncoder

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The JPEGEncoder class converts raw bitmap images into encoded images using Joint Photographic Experts Group (JPEG) compression. For information about the JPEG algorithm, see the document http://www.opennet.ru/docs/formats/jpeg.txt by Cristi Cuturicu.

Public Properties

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	Property		Defined By
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		contentType : String [read-only] The MIME type for the JPEG encoded image.	JPEGEncoder
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object

Public Methods

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	Method		Defined By
		JPEGEncoder(quality:Number = 50.0) Constructor.	JPEGEncoder
		encode(bitmapData:BitmapData):ByteArray Converts the pixels of BitmapData object to a JPEG-encoded ByteArray object.	JPEGEncoder
		encodeByteArray(byteArray:ByteArray, width:int, height:int, transparent:Boolean = true):ByteArray Converts a ByteArray object containing raw pixels in 32-bit ARGB (Alpha, Red, Green, Blue) format to a new JPEG-encoded ByteArray object.	JPEGEncoder
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		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
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String Returns the string representation of the specified object.	Object
		valueOf():Object Returns the primitive value of the specified object.	Object

Property Detail

contentType

property

contentType:String [read-only]

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

The MIME type for the JPEG encoded image. The value is "image/jpeg".

Implementation
public function get contentType():String

Constructor Detail

JPEGEncoder

()

Constructor

public function JPEGEncoder(quality:Number = 50.0)

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Constructor.

Parameters

quality:Number (default = 50.0) — A value between 0.0 and 100.0. The smaller the quality value, the smaller the file size of the resultant image. The value does not affect the encoding speed. Note that even though this value is a number between 0.0 and 100.0, it does not represent a percentage. The default value is 50.0.

Method Detail

encode

()

method

public function encode(bitmapData:BitmapData):ByteArray

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Converts the pixels of BitmapData object to a JPEG-encoded ByteArray object.

Parameters

bitmapData:BitmapData — The input BitmapData object.

Returns

ByteArray — Returns a ByteArray object containing JPEG-encoded image data.

encodeByteArray

()

method

public function encodeByteArray(byteArray:ByteArray, width:int, height:int, transparent:Boolean = true):ByteArray

Language Version:

ActionScript 3.0

Product Version:

Flex 3

Runtime Versions:

Flash Player 9, AIR 1.1

Converts a ByteArray object containing raw pixels in 32-bit ARGB (Alpha, Red, Green, Blue) format to a new JPEG-encoded ByteArray object. The original ByteArray is left unchanged. Transparency is not supported; however you still must represent each pixel as four bytes in ARGB format.

Parameters

	`byteArray:ByteArray` — The input ByteArray object containing raw pixels. This ByteArray should contain `4 width height` bytes. Each pixel is represented by 4 bytes, in the order ARGB. The first four bytes represent the top-left pixel of the image. The next four bytes represent the pixel to its right, etc. Each row follows the previous one without any padding.

	`width:int` — The width of the input image, in pixels.

	`height:int` — The height of the input image, in pixels.

	`transparent:Boolean` (default = `true`) — If `false`, alpha channel information is ignored.

Returns

ByteArray — Returns a ByteArray object containing JPEG-encoded image data.