CV_TYPE_NAME_SPARSE_MAT 3724 modules/core/src/persistence.cpp     cvStartWriteStruct( fs, name, CV_NODE_MAP, CV_TYPE_NAME_SPARSE_MAT );
CV_TYPE_NAME_SPARSE_MAT 4797 modules/core/src/persistence.cpp CvType sparse_mat_type( CV_TYPE_NAME_SPARSE_MAT, icvIsSparseMat,