static void paintTiledBackground_centered(Component c, Graphics g, BufferedImage image) {
  int w = c.getWidth();  
  int h = c.getHeight();  
  int tw = image.getWidth(), th = image.getHeight();
  
  // center of tile should be in center of image
  int shiftX = (w-tw)/2, shiftY = (h-th)/2;
  
  int y1 = mod(shiftY-1, th)-th+1;
  for (int x = mod(shiftX-1, tw)-tw+1; x < w; x += tw)
    for (int y = y1; y < h; y += th)
      g.drawImage(image, x, y, c);
}