To be fair you can implement any function over a finite domain using a sufficiently large lookup table.
The OP seems weird - it's clearly a beginner asking, but the answers assume an understanding of spatial frequency and Fourier transforms. I think it would be more intuitive to explain in terms of convolutions with small kernels.
The OP seems weird - it's clearly a beginner asking, but the answers assume an understanding of spatial frequency and Fourier transforms. I think it would be more intuitive to explain in terms of convolutions with small kernels.