/* ctor */ SURFFeatureDetextractor(cv::Ptr<cv::xfeatures2d::SURF> surf = cv::xfeatures2d::SURF::create())
     :
     m_hessianThreshold(surf->getHessianThreshold()),
     m_levels          (surf->getNOctaves()        ),
     m_octaveLayers    (surf->getNOctaveLayers()   ),
     m_extended        (surf->getExtended()        ),
     m_upright         (surf->getUpright()         ),
     CvSuperDetextractorAdaptor(surf) {}
 /* ctor */ KAZEFeatureDetextractor(cv::Ptr<cv::KAZE> kaze = cv::KAZE::create())
     :
     m_extended       (kaze->getExtended()     ),
     m_upright        (kaze->getUpright()      ),
     m_threshold      (kaze->getThreshold()    ),
     m_levels         (kaze->getNOctaves()     ),
     m_octaveLayers   (kaze->getNOctaveLayers()),
     m_diffusivityType(DiffuseType2String(kaze->getDiffusivity())),
     CvSuperDetextractorAdaptor(kaze) {}