'**DESCRIPTION**
Transforms an image according to Gamma Correction also known as
Power Law Transform.
**PARAMETERS**
* *gamma* - A non-negative real number.
**RETURNS**
A Gamma corrected image.
**EXAMPLE**
>>> img = Image(\'SimpleCV/sampleimages/family_watching_television_1958.jpg\')
>>> img.show()
>>> img.gammaCorrect(1.5).show()
>>> img.gammaCorrect(0.7).show()'

def gammaCorrect(self, gamma=1):

    if (gamma < 0):
        return 'Gamma    should    be    a    non-negative    real    number'
    scale = 255.0
    src = self.getNumpy()
    dst = ((((1.0 / scale) * src) ** gamma) * scale)
    return Image(dst)
