The insigtface face recognition project in mxnet training with scikit-learn Umeyama similir transform algorithm to esimate the affine transfrom matrix for aligning face. The available replacement function in opencv "estimateRigidTransform" is a little different from the scikit-learn one.this is a opencv implementation of Umeyama transform algorithm.
Least-squares estimation of transformation parameters between two point patterns", Shinji Umeyama, PAMI 1991, DOI: 10.1109/34.88573