// this copies to RGBA
static BufferedImage copyImage(Image img) {
  if (img == null) null;
  if (img cast BufferedImage)
    ret copyImage(img);
  int w = img.getWidth(null), h = img.getHeight(null);
  BufferedImage bi = newBufferedImage(w, h);
  drawImage(bi, img);
  ret bi;
}

// this one stays in color model. inconsistent i guess
static BufferedImage copyImage(BufferedImage bi) {
  if (bi == null) null;
  ColorModel cm = bi.getColorModel();
  boolean isAlphaPremultiplied = cm.isAlphaPremultiplied();
  WritableRaster raster = bi.copyData(bi.getRaster().createCompatibleWritableRaster());
  return new BufferedImage(cm, raster, isAlphaPremultiplied, null);
}