Compare rendering of an image, http://www.bbc.co.uk/vision/productisation/images/f/accordion_content.gif, in a browser and the program below. ImageView renders a black line at the bottom.

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.stage.Stage;

public class ImageTest extends Application {

    public static void main(String[] args) {
        launch(ImageTest.class, args);
    }

    @Override public void start(Stage stage) {
        Image img = new Image("http://www.bbc.co.uk/vision/productisation/images/f/accordion_content.gif");
        ImageView view = new ImageView(img);
        Scene sc = new Scene(new Group(view));
        stage.setScene(sc);
        stage.sizeToScene();
        stage.show();
    }
}