Actionscript convert background to Transparent - actionscript-3

Question

The purpose of the function is to covert the background to transparent and then return the bitmapdata, but it seems it do not work. The code is following:
private function transparentConverter( source:BitmapData, threshold:Number = 0.1 ):BitmapData
{
var bitmapData:BitmapData = new BitmapData( source.width, source.height, true, 0x00000000 );
bitmapData.lock();
var color:uint = source.getPixel( 0, 0 );
var x:uint, y:uint;
for ( y = 0; y < source.height; y++ )
{
for ( x = 0; x < source.width; x++ )
{
var c1:uint = source.getPixel( x, y );
var c2:uint = color;
var rx:uint = Math.abs((( c1 & 0xff0000 ) >> 16 ) - (( c2 & 0xff0000 ) >> 16 ));
var gx:uint = Math.abs((( c1 & 0xff00) >> 8 ) - (( c2 & 0xff00 ) >> 8 ));
var bx:uint = Math.abs(( c1 & 0xff ) - ( c2 & 0xff ));
var dist:uint = Math.sqrt( rx*rx + gx*gx + bx*bx );
if ( dist <= threshold )
{
bitmapData.setPixel32( x, y, 0x00000000 );
}else
{
bitmapData.setPixel32( x, y, c1 );
}
}
}
bitmapData.unlock();
return bitmapData;
}
Please advice.

Answer 1

Can you try this :
// This bitmapData should be defined for real, wherever you get that from ...
var source:BitmapData;
if(source == null)
trace("The source cannot be empty");
// Here you get the transformed BitmapData
var destination:bitmapData = transparentConverter( source );
// You apply it to a Bitmap in order to visualize it
var viewBitmap:Bitmap = new Bitmap(destination);
// You add the Bitmap to the stage so you can see it
addChild(viewBitmap);

Answer 2

Theo, thanks for your effort. I think the problem is the functions takes too long to run. After I try your script, a warning messages come out. It said the program takes more than 15 seconds to run and told me to stop running.
I think the function should be OK, but, maybe, not quite practical.
Theo, thank for your time and advice again.
I think the question can be closed.

Answer 3

Theo, the function seems can run, but take some time, however no bitmapdata return.
I receive the bitmpadata by the following code:
bitmapData = transparentConverter( bitmapData );
var bitmap:Bitmap = new Bitmap( bitmapData );
image1.source = bitmap;
The image do not appear.
And also, I can trace( c1 ), and I get a long list of data.
Thanks for your response.