First Level (2)
The choice of this particular division of the image is motivated by two factors:
- Particular magic numbers (divisors of power of 2,3,5,7) make faster the FFT algorithm used in the method (we used the FFTW libray by Matteo Frigo, MIT).
- Obligatory overlapping of the parts.
As the dimensions of the parts are not equal, we have a different charge at the first level.