In addition to @Elltz answer, we can use both fill and image for background:
someNode.setBackground(
new Background(
Collections.singletonList(new BackgroundFill(
Color.WHITE,
new CornerRadii(500),
new Insets(10))),
Collections.singletonList(new BackgroundImage(
new Image("image/logo.png", 100, 100, false, true),
BackgroundRepeat.NO_REPEAT,
BackgroundRepeat.NO_REPEAT,
BackgroundPosition.CENTER,
BackgroundSize.DEFAULT))));
Use
setBackground(
new Background(
Collections.singletonList(new BackgroundFill(
Color.WHITE,
new CornerRadii(0),
new Insets(0))),
Collections.singletonList(new BackgroundImage(
new Image("file:clouds.jpg", 100, 100, false, true),
BackgroundRepeat.NO_REPEAT,
BackgroundRepeat.NO_REPEAT,
BackgroundPosition.DEFAULT,
new BackgroundSize(1.0, 1.0, true, true, false, false)
))));
(different last argument) to make the image full-window size.