skimage2.exposure.adjust_gamma#

skimage2.exposure.adjust_gamma(image, gamma=1, gain=1)[source]#

Perform gamma correction on the input image.

Gamma correction is a power-law transform [1]. This function transforms the input image pixel-wise according to the power law image**gamma after scaling each pixel to the range 0 to 1. Then it is rescaled to its original range and muliplied by gain.

Parameters:
imagendarray

Input image.

gammafloat, optional

Non negative real number. Default value is 1.

gainfloat, optional

The constant multiplier. Default value is 1.

Returns:
outndarray

Gamma corrected output image.

See also

adjust_log

Notes

For gamma greater than 1, the histogram will shift towards left and the output image will be darker than the input image.

For gamma less than 1, the histogram will shift towards right and the output image will be brighter than the input image.

References

Examples

>>> import _skimage2 as ski2
>>> image = ski2.util.img_as_float(ski2.data.moon())
>>> gamma_corrected = ski2.exposure.adjust_gamma(image, 2)
>>> # Output is darker for gamma > 1
>>> image.mean() > gamma_corrected.mean()
True