Hyperspectral super-resolution via coupled tensor ring factorization

•Based on TR factorization, we developed a degradation model from the HR-HSI to the MSI and HSI. We proposed a CTRF model for HSR tasks. The nuclear norm regularization of the third TR core with mode-2 unfolding was introduced to further exploit the global spectral low-rank property of the HR-HSI.•We analyzed the superiority of the CTRF model for HSR and developed an efficient alternating iteration method for the proposed model. The experiments demonstrated the advantage of the CTRF model compared to the previous matrix/tensor and deep learning methods.