sinc_filter#

class deepinv.physics.blur.sinc_filter(factor=2, length=11, windowed=True)[source]#

Bases:

Anti-aliasing sinc filter multiplied by a Kaiser window.

The kaiser window parameter is computed as follows:

\[A = 2.285 \cdot (L - 1) \cdot 3.14 \cdot \Delta f + 7.95\]

where \(\Delta f = 1 / \text{factor}\). Then, the beta parameter is computed as:

\[\begin{split}\begin{equation*} \beta = \begin{cases} 0 & \text{if } A \leq 21 \\ 0.5842 \cdot (A - 21)^{0.4} + 0.07886 \cdot (A - 21) & \text{if } 21 < A \leq 50 \\ 0.1102 \cdot (A - 8.7) & \text{otherwise} \end{cases} \end{equation*}\end{split}\]
Parameters:
  • factor (float) – Downsampling factor.

  • length (int) – Length of the filter.