LuptonAsinhStretch

class astropy.visualization.LuptonAsinhStretch(stretch=5, Q=8)

Bases: BaseStretch

A modified asinh stretch, with some changes to the constants relative to AsinhStretch.

The stretch is given by:

\[\begin{split}& y = {\rm asinh}\left(\frac{Q * x}{stretch}\right) * \frac{frac}{{\rm asinh}(frac * Q)} \\ & frac = 0.1\end{split}\]

Parameters:

stretchfloat, optional

Linear stretch of the image. stretch must be greater than 0. Default is 5.

Qfloat, optional

The asinh softening parameter. Q must be greater than 0. Default is 8.

Notes

Based on the asinh stretch presented in Lupton et al. 2004 (https://ui.adsabs.harvard.edu/abs/2004PASP..116..133L).

Methods Summary

__call__(values[, clip, out])

Transform values using this stretch.

Methods Documentation

__call__(values, clip=False, out=None)

Transform values using this stretch.

Parameters:

valuesarray_like

The input values, which should already be normalized to the [0:1] range.

clipbool, optional

If True (default), values outside the [0:1] range are clipped to the [0:1] range.

outndarray, optional

If specified, the output values will be placed in this array (typically used for in-place calculations).

Returns:

resultndarray

The transformed values.