code: protected void adjustHomographSign( AssociatedPair p , DMatrixRMaj H ) {
  		double val = GeometryMath_F64.innerProd(p.p2, H, p.p1);
  
  		if( val < 0 )
  			CommonOps_DDRM.scale(-1, H);
  	}
docs: Since the sign of the homography is ambiguous a point is required to make sure the correct
  one was selected.
  
  @param p test point, used to determine the sign of the matrix.