I want to compute the following 2D Fourier transform for the following matrix \begin{equation}u=\left[\begin{array}{lll} 10 & 0 & 0 \\ 10 & 0 & 0 \end{array}\right]\end{equation}
And I don't know which are the coefficients N and M from the formula of Fourier. Since:
\begin{equation}c_{k, p}=\sum_{n=0}^{N-1} \sum_{m=0}^{M-1} x(n, m) e^{-2 \pi i\left(\frac{k n}{N}+\frac{p m}{M}\right)}, \quad k=0,1, \ldots, N-1 \cdot p=0,1, \ldots, M-1\end{equation}