prtools.gauss_kernel#

gauss_kernel(shape, sigma, oversample=1, fftshift=True)[source]#

2D Gaussian filter kernel

This function returns the transfer function of a normalized 2D Gaussian function.

Parameters:

  • shape (int or tuple of int) – Shape of the kernel

  • sigma (float) – Standard deviation of Gaussian. Providing two values allows for non-symmetric Gaussian interpreted as (sigma_row, sigma_col)

  • oversample (float, optional) – Oversampling factor to represent in the kernel. Default is 1.

  • fftshift (bool, optional) – If True (default), the kernel is FFT-shifted before it is returned.

Return type:

ndarray

See also

fftconv(), gauss_blur(), gauss()

Examples

>>> blur_kernel = prtools.gauss_kernel((256,256), 1)
>>> plt.imshow(blur_kernel, cmap='gray')
../_images/prtools-gauss_kernel-1.png

Note this is functionally equivalent to

>>> r = np.fft.fftfreq(256)
>>> c = np.fft.fftfreq(256)
>>> sigma = 1
>>> blur_kernel = np.fft.fftshift(prtools.gauss(r, c, 1/(2*np.pi*sigma)))
>>> plt.imshow(blur_kernel, cmap='gray')
../_images/prtools-gauss_kernel-2.png