public static BufferedImage sclae2(BufferedImage img, int w2, int h2){
        int w1 = img.getWidth();
        int h1 = img.getHeight();
        BufferedImage output = new BufferedImage(w2, h2, BufferedImage.TYPE_INT_RGB);
        double x_ratio = (double)w1/w2;
        double y_ratio = (double)h1/h2;
        for(int i=0; i<w2; i++){
            for (int j = 0; j < h2; j++) {
                int rgb = img.getRGB((int)Math.floor(i*x_ratio), (int)Math.floor(j*y_ratio));
                output.setRGB(i, j, rgb);
            }
        }
        return output;
    }