code: protected void detectFeatures( int scaleIndex ) {
  		extractor.process(dogTarget);
  		FastQueue<NonMaxLimiter.LocalExtreme> found = extractor.getLocalExtreme();
  
  		derivXX.setImage(dogTarget);
  		derivXY.setImage(dogTarget);
  		derivYY.setImage(dogTarget);
  
  		for (int i = 0; i < found.size; i++) {
  			NonMaxLimiter.LocalExtreme e = found.get(i);
  
  			if( e.max ) {
  				if( isScaleSpaceExtremum(e.location.x, e.location.y, e.getValue(), 1f)) {
  					processFeatureCandidate(e.location.x,e.location.y,e.getValue(),e.max);
  				}
  			} else if( isScaleSpaceExtremum(e.location.x, e.location.y, e.getValue(), -1f)) {
  				processFeatureCandidate(e.location.x,e.location.y,e.getValue(),e.max);
  			}
  		}
  	}
docs: Detect features inside the Difference-of-Gaussian image at the current scale
  
  @param scaleIndex Which scale in the octave is it detecting features inside up.
  Primarily provided here for use in child classes.