'**SUMMARY**
Return a numpy array of the average color of the area covered by each Feature.
**RETURNS**
Returns an array of RGB triplets the correspond to the mean color of the feature.
**EXAMPLE**
>>> img = Image("lenna")
>>> kp = img.findKeypoints()
>>> c = kp.meanColor()'

def meanColor(self):

    return np.array([f.meanColor() for f in self])
