static MinimalRecognizer edgeDetectorConfig1() {
  new MinimalRecognizer rec;
  rec.childLivelinessFactor = 4/*2*//*1.5*/;
  rec.featureSize = 0.06;
  rec.maxSteps = 1000;
  rec.maxDescentLevel = 5;
  rec.finalMinLiveliness = .3;
  rec.fixFeatureSize();
  ret rec;
}