Animated GIF: retain transparency without ghosting

Question

In trying to make an animated GIF from an image with transparency this code is producing a ghosting effect from the earlier image frames.

_{Image of 3rd frame, which shows the first two frames beneath the final frame}

How can the code be altered to produce a 'clean' animated image for all frames?

Note: The code uses two methods, written by GeoffTitmus & Maxideon, that were formerly on the Oracle forums site. The links I first saw referenced in the code (in the JavaDocs section) have long since disappeared, so were removed. Other than that, only a few JavaDoc warnings were corrected, otherwise they are exactly as found from around the internet or as used in my older code projects.

import java.awt.*;
import java.awt.image.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
import java.io.*;
import javax.imageio.*;
import javax.imageio.metadata.IIOInvalidTreeException;
import javax.imageio.stream.*;
import javax.imageio.metadata.*;
import org.w3c.dom.Node;
import java.net.URL;

public class AnimatedGifWithTransparency {

    private JComponent ui = null;
    public final String PATH = "https://i.stack.imgur.com/P59NF.png";
    private BufferedImage image;

    AnimatedGifWithTransparency() {
        try {
            initUI();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    /**
     * @author GeoffTitmus
     * @param out OutputStream A stream in which to store the animation.
     * @param frames BufferedImage[] Array of BufferedImages, the frames of the
     * animation.
     * @param delayTimes String[] Array of Strings, representing the frame delay
     * times.
     * @throws Exception
     */
    public static void saveAnimate(OutputStream out, BufferedImage[] frames, String[] delayTimes) throws Exception {

        ImageWriter iw = ImageIO.getImageWritersByFormatName("gif").next();

        ImageOutputStream ios = ImageIO.createImageOutputStream(out);
        iw.setOutput(ios);
        iw.prepareWriteSequence(null);

        for (int i = 0; i < frames.length; i++) {
            BufferedImage src = frames[i];
            ImageWriteParam iwp = iw.getDefaultWriteParam();
            IIOMetadata metadata = iw.getDefaultImageMetadata(new ImageTypeSpecifier(src), iwp);

            configure(metadata, delayTimes[i], i);

            IIOImage ii = new IIOImage(src, null, metadata);
            iw.writeToSequence(ii, null);
        }

        iw.endWriteSequence();
        ios.close();
    }

    /**
     * @author Maxideon
     * @param meta
     * @param delayTime String Frame delay for this frame.
     * @param imageIndex
     */
    public static void configure(IIOMetadata meta,
            String delayTime,
            int imageIndex) {

        String metaFormat = meta.getNativeMetadataFormatName();

        if (!"javax_imageio_gif_image_1.0".equals(metaFormat)) {
            throw new IllegalArgumentException(
                    "Unfamiliar gif metadata format: " + metaFormat);
        }

        Node root = meta.getAsTree(metaFormat);

        //find the GraphicControlExtension node
        Node child = root.getFirstChild();
        while (child != null) {
            if ("GraphicControlExtension".equals(child.getNodeName())) {
                break;
            }
            child = child.getNextSibling();
        }

        IIOMetadataNode gce = (IIOMetadataNode) child;
        gce.setAttribute("userDelay", "FALSE");
        gce.setAttribute("delayTime", delayTime);

        //only the first node needs the ApplicationExtensions node
        if (imageIndex == 0) {
            IIOMetadataNode aes
                    = new IIOMetadataNode("ApplicationExtensions");
            IIOMetadataNode ae
                    = new IIOMetadataNode("ApplicationExtension");
            ae.setAttribute("applicationID", "NETSCAPE");
            ae.setAttribute("authenticationCode", "2.0");
            byte[] uo = new byte[]{
                //last two bytes is an unsigned short (little endian) that
                //indicates the the number of times to loop.
                //0 means loop forever.
                0x1, 0x0, 0x0
            };
            ae.setUserObject(uo);
            aes.appendChild(ae);
            root.appendChild(aes);
        }

        try {
            meta.setFromTree(metaFormat, root);
        } catch (IIOInvalidTreeException e) {
            //shouldn't happen
            throw new Error(e);
        }
    }

    private BufferedImage getShiftedImage(int frame) {
        int w = image.getWidth();
        int h = image.getHeight();
        BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
        Graphics g = bi.getGraphics();

        int xOffPos = frame*w/3;
        int xOffNeg = xOffPos-w;
        g.drawImage(image, xOffNeg, 0, ui);
        g.drawImage(image, xOffPos, 0, ui);

        g.dispose();
        return bi;
    }

    public final void initUI() throws IOException {
        if (ui != null) {
            return;
        }
        image = ImageIO.read(new URL(PATH));

        ui = new JPanel(new BorderLayout(4, 4));
        ui.setBorder(new EmptyBorder(4, 4, 4, 4));

        BufferedImage[] frames = {
            getShiftedImage(0),
            getShiftedImage(1),
            getShiftedImage(2)
        };

        String[] delayTimes = {
            "50","50","50"
        };
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            saveAnimate(baos, frames, delayTimes);
        } catch (Exception ex) {
            ex.printStackTrace();
            return;
        }
        byte[] bytes = baos.toByteArray();
        ui.add(new JLabel(new ImageIcon(bytes)));
    }

    public JComponent getUI() {
        return ui;
    }

    public static void main(String[] args) {
        Runnable r = () -> {
            AnimatedGifWithTransparency o = new AnimatedGifWithTransparency();

            JFrame f = new JFrame(o.getClass().getSimpleName());
            f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            f.setLocationByPlatform(true);

            f.setContentPane(o.getUI());
            f.pack();
            f.setMinimumSize(f.getSize());

            f.setVisible(true);
        };
        SwingUtilities.invokeLater(r);
    }
}