smpy.filters.starlet.b3spline_filter

smpy.filters.starlet.b3spline_filter(step=1)

Create a B3-spline filter for the starlet transform.

Generate the 1D B3-spline filter kernel used in the starlet wavelet transform with appropriate dilation for the à trous algorithm.

Parameters:

step (int, optional) – The dilation step for the à trous algorithm.

Returns:

kernel – The 1D B3-spline filter with appropriate spacing.

Return type:

numpy.ndarray

Notes

The B3-spline filter coefficients are [1/16, 1/4, 3/8, 1/4, 1/16]. For step > 1, zeros are inserted between coefficients according to the à trous algorithm.