scale_image¶
-
astropy.visualization.
scale_image
(image, scale='linear', power=1.0, asinh_a=0.1, min_cut=None, max_cut=None, min_percent=None, max_percent=None, percent=None, clip=True)[source] [edit on github]¶ 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 tomin_cut
before scaling the image. The default is the image minimum.min_cut
overridesmin_percent
.max_cut : float, optional
The pixel value of the maximum cut level. Data values greater than
min_cut
will set tomin_cut
before scaling the image. The default is the image maximum.max_cut
overridesmax_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
overridespercent
.max_percent : float, optional
The percentile value used to determine the pixel value of maximum cut level. The default is 100.0.
max_percent
overridespercent
.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 eithermin_percent
ormax_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.