bitmapdata.draw failing silently - actionscript-3

Question

I am trying to read an image using Loader (variable name is faceimage) and trying to pass the bitmapdata of that image to a function called detect. However, it is failing in the line where I am trying to get the Bitmap.
bmpTarget = new Bitmap( new BitmapData( faceImage.width, faceImage.height, false ) )
bmpTarget.bitmapData.draw( faceImage ); // Fails, no errors shown
detector.detect( bmpTarget.bitmapData );
I narrowed down to this line by putting trace statements above and below the failing line. The faceImage contains valid data which I verified by displaying contents on screen. I also tried
bmpTarget = Bitmap(BitmapData(faceImage.content))
but in vain. Am I doing something wrong here?

Answer 1

It could be a sandbox/crossdomain issue. Certain crossdomain settings prohibit drawing the content of a loaded image to a bitmapData. You can get around it by loading the raw image data with URLLoader and then using loadBytes on Loader.

Answer 2

As noted from:
Why do Loader objects kill bitmapdata draw();?
You likely need a LoaderContext.
loader.load("http://www.example.com/myimage.jpg", new LoaderContext(true));
Otherwise, you can load images from other sites but not access the actual bitmapData, which a draw() requires.

Answer 3

I wonder if you're trying to access the bitmapdata before it's been loaded?
Perhaps try using a complete listener...
var _urlRequest:URLRequest = new URLRequest("urlToImage");
var faceImage:Loader = new Loader;
faceImage.load(_urlRequest);
faceImage.addEventListener(IOErrorEvent.IO_ERROR, function(e:IOErrorEvent):void{ trace(e) });
faceImage.contentLoaderInfo.addEventListener(Event.COMPLETE, imageLoaded, false, 0, true);
function imageLoaded(e:Event):void {
faceImage.contentLoaderInfo.removeEventListener(Event.COMPLETE, imageLoaded);
var bmpTarget:Bitmap = e.target.content;
detector.detect( bmpTarget.bitmapData );
}