Table 2 Separable kernels used in the TFD selection process

$0.54+0.5\text{cos}\left(\frac{2\mathrm{\pi n}}{N}\right)$

$0.54+0.46\text{cos}\left(\frac{2\mathrm{\pi m}}{M}\right)$

(N, M)

$0.54+0.5\text{cos}\left(\frac{2\mathrm{\pi n}}{N}\right)$

$\text{exp}\left(\frac{-m^2}{2{\sigma }^2}\right)$

(N, σ

$\frac{|\mathrm{\Gamma }\left(\beta +\text{j}n\right){|}^2}{\mathrm{\Gamma }\left(\beta \right)}$

$0.54+0.46\text{cos}\left(\frac{2\mathrm{\pi m}}{M}\right)$

(β ,M)