Displaying an image from a base64 string

[Gunderak]

Hey, I'm trying to display an image in a GuiBitmapCtrl.
The image is encoded with base64.
So far I have this.

PHP Code:

    temp.img = "the base64 string.";  //Too long to post here lol.
    new GuiBitmapCtrl("TeamViewer_Display"){
      bitmap = "block.png";
      profile = GuiDefaultProfile;
      height = 359;
      width = 520;
      bitmap = base64decode(img);
    } 


But so far it's displaying nothing.