private BufferedImage canvasToImage(Canvas cnvs) {
        int w = cnvs.getWidth();
        int h = cnvs.getHeight();
        int type = BufferedImage.TYPE_INT_RGB;
        BufferedImage image = new BufferedImage(w,h,type);
        Graphics2D g2 = image.createGraphics();
        cnvs.paint(g2);
        g2.dispose();
        return image;
    }