I place ImageView inside BorderPane. When Stage is show a image was sharp. but then i resize stage a image was blur (some size blue,some size not blur)

code is simple as below

public class ImageBrowser extends Application {

    @Override
    public void start(Stage primaryStage) {
        StackPane root = new StackPane();
        BorderPane borderPane = new BorderPane();
        root.getChildren().add(borderPane);
        ImageView imageView = new ImageView(getClass().getResource("test.png").toExternalForm());
        imageView.setPreserveRatio(true);
        borderPane.setCenter(imageView);
        Scene scene = new Scene(root, 300, 250);

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}