static int from332(byte x) {
  /*int r = ((x >> 5) & 7) << 5;
  int g = ((x >> 2) & 7) << 5;
  int b = (x & 3) << 6;*/
  int r = iround(((x >> 5) & 7)*255.0/7);
  int g = iround(((x >> 2) & 7)*255.0/7);
  int b = iround((x & 3)*255.0/3);
  ret (r << 16) | (g << 8) | b;
}