get_image_variance

VarianceGenerator.get_image_variance(dqe)

[Deprecated] Calculates the variance in scattered intensity as a function of scattering vector. The calculated variance is normalised by the mean squared, as is appropriate for the distribution of intensities. This causes a problem if Poisson noise is significant in the data, resulting in a divergence of the Poisson noise term. To in turn remove this effect, we subtract a dqe/mean_dp term (although it is suggested that dqe=1) from the data, creating a “poisson noise-free” corrected variance pattern. DQE is fitted to make this pattern flat.

Parameters:

dqe (float) – Detective quantum efficiency of the detector for Poisson noise correction.

Returns:

varims – A two dimensional Signal class object containing the mean DP, mean squared DP, and variance DP, and a Poisson noise-corrected variance DP.

Return type:

ImageVariance

Notes

Deprecated since version 0.15: Function get_image_variance() is deprecated and will be removed in version 1.0.0. Use pyxem.signals.diffraction2d.get_variance() instead.