// similarity = e.g. 0.99f
static FoundImg rgbRawImageSearch_searchHereOnly(RGBImage big, RGBImage pat, float similarity, Pt searchHereOnly) {
  int wp = pat.getWidth(), hp = pat.getHeight();
  int w = big.getWidth(), h = big.getHeight();
  float maxError = (1f-similarity)*wp*hp;
  float diff = rgbImageSectionsSimilarity(big, pat, searchHereOnly.x, searchHereOnly.y, maxError);
  if (diff <= maxError) {
    float sim = 1-diff/(wp*hp);
    ret new FoundImg(new Rect(searchHereOnly.x, searchHereOnly.y, wp, hp), sim);
  }
  null;
}

Began life as a copy of #1006913