code: def normalize(x:TensorImage, mean:FloatTensor,std:FloatTensor)->TensorImage:
      "Normalize `x` with `mean` and `std`."
      return (x-mean[...,None,None]) / std[...,None,Nonef normalize(x:TensorImage, mean:FloatTensor,std:FloatTensor)->TensorImage:
      "Normalize `x` with `mean` and `std`."
      return (x-mean[...,None,None]) / std[...,None,None]
docs: Normalize `x` with `mean` and `std`.