// similarity = e.g. 0.99f
static Rect rgbFindMostSimilarClip(RGBImage big, RGBImage pat, L<Rect> clips, float similarity) {
  Rect found;
  int wp = pat.getWidth(), hp = pat.getHeight();
  int w = big.getWidth(), h = big.getHeight();
  float maxError = (1f-similarity)*wp*hp;
  for (Rect r : clips) {
    float diff = rgbImageSectionsSimilarity(big, pat, r.x, r.y, maxError);
    if (diff <= maxError) {
      float sim = 1-diff/(wp*hp);
      found = new Rect(x, y, wp, hp);
      maxError = diff;
    }
  }
  ret found;
}