I tested this code in order to create dialog with image.
final int xSize = 400;
final int ySize = 280;
final Color backgroundColor = Color.WHITE;
final Strin
Try this:
img = new Image("/logo.png");
If no protocol part indicating a URL (as http: or file:) is given, the file is supposed to reside in the default package. If you want it to put in a different package say com.my.images you add this information in a path like manner:
img = new Image("/com/my/images/logo.png");