Matrix comparation

Hello,
I have an object that contains a matrix 16x16 of numbers between 0-65535.
I would need somehow, to be able to compere this matrix with another and get the difference result in percent.

What would be the best approach to it?

Well i was comparing each corresponding element of the 2 matrix, if they dont match im getting the difference between them in percentage, then on all difference i'm getting the arithmetic median between the differences!