“…Recent concepts that utilize both spatial and spectral information have shown improved classification performance over the spectral centric of BS schemes [ 53 , 54 , 55 ]. There are various different methodologies for implementing these concepts in BS: Clustering based [ 13 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 ], deep learning methods [ 65 , 66 , 67 , 68 , 69 , 70 ], machine learning methods [ 71 , 72 , 73 , 74 ], and a hierarchy of several methodologies combined together [ 75 , 76 ], have been widely reported. Furthermore, some of these require supervision in which training data are needed to optimize the model [ 77 , 78 ], while others are unsupervised without the need of prior information.…”