LuptonAsinhZscaleStretch

class astropy.visualization.LuptonAsinhZscaleStretch(image, Q=8, pedestal=None)

Bases: LuptonAsinhStretch

A modified asinh stretch, where the linear stretch is calculated using zscale.

The stretch is given by:

\[\begin{split}& y = {\rm asinh}\left(\frac{Q * x}{stretch}\right) * \frac{frac}{{\rm asinh}(frac * Q)} \\ & frac = 0.1 \\ & stretch = z2 - z1\end{split}\]

Parameters:

image1ndarray or numpy:array_like

The image to analyse, or a list of 3 images to be converted to an intensity image.

Qpython:float, optional

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

pedestalor numpy:array_like, optional

The value, or array of 3 values, to subtract from the images(s) before determining the zscaling. Default is None (nothing subtracted).