code: protected double computeErrors(Se3_F64 fiducialToCamera ) {
  		if( fiducialToCamera.T.z < 0 ) {
  			// the low level algorithm should already filter this code, but just incase
  			return Double.MAX_VALUE;
  		}
  
  		double maxError = 0;
  
  		for( int i = 0; i < 4; i++ ) {
  			maxError = Math.max(maxError,computePixelError(fiducialToCamera, points.get(i).location, listObs.get(i)));
  		}
  
  		return maxError;
  	}
docs: Compute the sum of reprojection errors for all four points
  @param fiducialToCamera Transform being evaluated
  @return sum of Euclidean-squared errors