This is the brute force method of computing correlation by moving the kernel over the input image and find the sum of products of the overlapping pixels
This method performs correlation by transforming the image and kernel using Fourier Transform and performing element-wise multiplication and finally performing inverse fourier transform. This method performs fourier and inverse fourier transform using a recursive approach.
In this method, an iterative apprpoach of corr_fft_v1 is implemented. This is so that it becomes easy to implement in hardware.
In this method, the iterative approach of corr_fft_v2 is optimized by precomputing the w (omega) terms and storing them in a hash table.