getPixel (BitmapData.getPixel method)

public getPixel(x:Number, y:Number) : Number

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 are performing operations. All Flash Lite player methods take and return unmultiplied values. The internal pixel representation is unmultiplied before it is returned as a value. During a set operation, the pixel value is premultiplied before setting the raw image pixel.

Availability

Flash Lite 3.1

Parameters

x:Number - The x position of the pixel.

y:Number - The y position of the pixel.

Returns

Number - A number that represents an RGB pixel value. If the (x, y) coordinates are outside the bounds of the image, 0 is returned.

Example

The following example uses the getPixel() method to retrieve the RGB value of a pixel at a specific x and y position.

import flash.display.BitmapData; 
 
var myBitmapData:BitmapData = new BitmapData(100, 80, false, 0x00CCCCCC); 
 
var mc:MovieClip = this.createEmptyMovieClip("mc", this.getNextHighestDepth()); 
mc.attachBitmap(myBitmapData, this.getNextHighestDepth()); 
trace("0x" + myBitmapData.getPixel(0, 0).toString(16)); // 0xcccccc