def exportValue(self, vf, value):
        m = StrStrHashMap(value)
        keysAndValues = []
        for i in m.keys():
            keysAndValues.append(i)
            keysAndValues.append(m[i])
def make_grayscale(img):
    ret = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
    return ret