What is the normalization method so that there is no negative value?
Without more information about your source code and the packages you're using, this is really more of a data science question than a python question.
To answer your question, a more than satisfactory method in most circumstances it min-max scaling. Simply normalize each coordinate of your images between 0 and 1. Whether or not that is appropriate for your circumstance depends on what you intend to do next with that data.
I am trying to normalize MR image.
There is a negative value in the MR image.
So the MR image was normalized using the Gaussian method, resulting in a negative area. 
But i don't want to get negative area.
My question:
     What is the normalization method so that there is no negative value?
Thanks in advance