skimage2.exposure.is_low_contrast#

skimage2.exposure.is_low_contrast(image, fraction_threshold=0.05, lower_percentile=1, upper_percentile=99, method='linear')[source]#

Determine if an image is low contrast.

Parameters:

imagearray-like: The image under test.
fraction_thresholdfloat, optional: The low contrast fraction threshold. An image is considered low- contrast when its range of brightness spans less than this fraction of its data type’s full range. [1]
lower_percentilefloat, optional: Disregard values below this percentile when computing image contrast.
upper_percentilefloat, optional: Disregard values above this percentile when computing image contrast.
methodstr, optional: The contrast determination method. Right now the only available option is “linear”.

Returns:

outbool: True when the image is determined to be low contrast.

Notes

For boolean images, this function returns False only if all values are the same (the method, threshold, and percentile arguments are ignored).

References

[1]

https://scikit-image.org/docs/dev/user_guide/data_types.html

Examples

>>> image = np.linspace(0, 0.04, 100)
>>> is_low_contrast(image)
True
>>> image[-1] = 1
>>> is_low_contrast(image)
True
>>> is_low_contrast(image, upper_percentile=100)
False