static S uploadToImageServer_new_jpg(BufferedImage img, S name) {
  ret uploadToImageServer_new_jpg(toJPEG(img), name);
}

static S uploadToImageServer_new_jpg(byte[] imgData, S name) {
  S page = postPage(imageServerURL() + "upload", "data", bytesToHex(imgData), "name", name);
  print(page);
  Matcher m = Pattern.compile("/images/([0-9]+)").matcher(page);
  if (!m.find()) fail("Image server said: " + page);
  ret imageServerURL() + m.group(1);
}