scale_image

astropy.visualization.scale_image(*args, **kwargs)

Deprecated since version 1.3: The scale_image function is deprecated and may be removed in a future version. Use simple_norm instead.

Perform scaling/stretching of an image between minimum and maximum cut levels.

Parameters:

image : array-like

The array of values.

scale : {{‘linear’, ‘sqrt’, ‘power’, log’, ‘asinh’}}

The scaling/stretch function to apply to the image. The default is ‘linear’.

power : float, optional

The power index for scale='power' image scaling. The default is 1.0.

asinh_a : float, optional

For scale='asinh' image scaling, the value where the asinh curve transitions from linear to logarithmic behavior, expressed as a fraction of the normalized image. Must be in the range between 0 and 1.

min_cut : float, optional

The pixel value of the minimum cut level. Data values less than min_cut will set to min_cut before scaling the image. The default is the image minimum. min_cut overrides min_percent.

max_cut : float, optional

The pixel value of the maximum cut level. Data values greater than min_cut will set to min_cut before scaling the image. The default is the image maximum. max_cut overrides max_percent.

min_percent : float, optional

The percentile value used to determine the pixel value of minimum cut level. The default is 0.0. min_percent overrides percent.

max_percent : float, optional

The percentile value used to determine the pixel value of maximum cut level. The default is 100.0. max_percent overrides percent.

percent : float, optional

The percentage of the image values used to determine the pixel values of the minimum and maximum cut levels. The lower cut level will set at the (100 - percent) / 2 percentile, while the upper cut level will be set at the (100 + percent) / 2 percentile. The default is 100.0. percent is ignored if either min_percent or max_percent is input.

clip : bool, optional

Whether to clip the result to the range [0:1].

Returns:

image : ndarray

The array of the scaled/stretched image with a minimum of 0.0 and a maximum of 1.0.