This is the 2-D Fast DOST Decomposition and reconstruction. The computational complexity is O(NlnN)
This code only take the input of size 2^m x 2^n due to the using of the FFT and the blocking strategy. For the input not at dyadic size, if can be padded first.
The full code has been added to this version instead of only the decomposition in the first version. Enjoy!