Java2D: get coordinates from rotated image

Question

I made a methode to rotate a image (most code found in stackoverflow's nice answers). Now I need to cut the image: (1) by the outline and (2) inline the image (no border shown). But I don't know how to do that and I found no sample in all answers here. Is it possible to get the coordinates (all four edge points) from the rotated image somehow? Thanks for help.

public static BufferedImage rotateTest(BufferedImage image, double degrees) {
    // --- get image size
    int w = image.getWidth();
    int h = image.getHeight();
    // --- need longest side
    int m = w;
    if (h > w) {
        m = h;
    }
    // --- double length for rotating
    m = m * 2;
    // --- rotate component
    BufferedImage result = new BufferedImage(m, m, image.getType());
    Graphics2D g = (Graphics2D) result.getGraphics();
    // --- create transform
    AffineTransform transformer = new AffineTransform();
    // --- translate it to the center of the component
    transformer.translate(result.getWidth() / 2, result.getHeight() / 2);
    // --- do the actual rotation
    transformer.rotate(Math.toRadians(degrees));
    // --- translate the object so that you rotate it around the center
    transformer.translate(-image.getWidth() / 2, -image.getHeight() / 2);
    // --- anti aliasing
    g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
        RenderingHints.VALUE_INTERPOLATION_BILINEAR);
    g.setRenderingHint(RenderingHints.KEY_RENDERING,
        RenderingHints.VALUE_RENDER_QUALITY);
    g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
        RenderingHints.VALUE_ANTIALIAS_ON);
    // --- drawing
    g.drawImage(image, transformer, null);
    // --- done
    g.dispose();
    // --- cut to outline

    // --- run out
    return result;
}