FileLocator.find(
    FrameworkUtil.getBundle(this.getClass()),
    new Path("icon/someimage.png"),
    null)

Canvas canvas = new Canvas(composite, SWT.NO_REDRAW_RESIZE);
canvas.setBounds(0, 0, IMG_WIDTH, IMG_HEIGHT);
canvas.addPaintListener(new PaintListener() {
    public void paintControl(PaintEvent e) {
        e.gc.drawImage(
            ImageDescriptor
            .createFromURL(
                FileLocator.find(
                    FrameworkUtil.getBundle(this.getClass()),
                    new Path("icon/someimage.png"),
                    null)
             ).createImage(), 0, 0);
    }
});