As an example, the oriented first derivative of a 2D Gaussian is a steerable filter, for which the basis filters are the partial derivatives of a 2D Gaussian with respect to x and y.
The oriented first derivative of a 2D Gaussian is a steerable filter. This is as an example. The basis filters are the partial derivatives of a 2D Gaussian with respect to x. The basis filters are the partial derivatives of a 2D Gaussian with respect to y for a steerable filter.