Bartlett Window

A Bartlett Window is simply a tent function, i.e.

$$\textrm{Bartlett}(x,\tau)=\left \{ \begin{array}{cl} 1 - \fr... ...\vert x\vert < \tau$}\\ 0 & \textrm{else} \end{array} \right.$$ (6)

The frequency response approaches zero more smoothly but does not approximate the ideal frequency response below $\pi$ as good as the truncated cosc function. This rather simple windowing function, although said to be sufficient in the Numerical Recipes in C (used in another context) [17], performs quite poor when used for gradient reconstruction.