hyperspy.misc.holography.tools module

hyperspy.misc.holography.tools.calculate_carrier_frequency(holo_data, sb_position, scale)

Calculates fringe carrier frequency of a hologram

Parameters

• holo_data (ndarray) – The data of the hologram.

• sb_position (tuple) – Position of the sideband with the reference to non-shifted FFT

• scale (tuple) – Scale of the axes that will be used for the calculation.

Returns

Return type

Carrier frequency

hyperspy.misc.holography.tools.estimate_fringe_contrast_fourier(holo_data, sb_position, apodization='hanning')

Estimates average fringe contrast of a hologram by dividing amplitude of maximum pixel of sideband by amplitude of FFT’s origin.

Parameters

• holo_data (ndarray) – The data of the hologram.

• sb_position (tuple) – Position of the sideband with the reference to non-shifted FFT

• apodization (string, None) – Use ‘hanning’, ‘hamming’ or None to apply apodization window in real space before FFT Apodization is typically needed to suppress the striking due to sharp edges of the which often results in underestimation of the fringe contrast. (Default: ‘hanning’)

Returns

Return type

Fringe contrast as a float