adjust-gamma

adjust_gamma

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

Performs Gamma Correction on the input image.

Also known as Power Law Transform. This function transforms the input image pixelwise according to the equation O = I**gamma after scaling each pixel to the range 0 to 1.

Parameters:	image : ndarray Input image. gamma : float Non negative real number. Default value is 1. gain : float The constant multiplier. Default value is 1.
Returns:	out : ndarray 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

[R82]

http://en.wikipedia.org/wiki/Gamma_correction

Examples

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