1.将numpy矩阵转换为Tensor张量
sub_ts = torch.from_numpy(sub_img) #sub_img为numpy类型
2.将Tensor张量转化为numpy矩阵
sub_np1 = sub_ts.numpy() #sub_ts为tensor张量
3.将numpy转换为Variable
sub_va = Variable(torch.from_numpy(sub_img))
4.将Variable张量转化为numpy
sub_np2 = sub_va.data.numpy()