单项选择题
A.cv2.morphologyEx(image,cv2.MORPH_BLACKHAT,e)B.cv2.morphologyEx(image,cv2.MORPH_CLOSE,e)C.cv2.morphologyEx(image,cv2.MORPH_GRADIENT,e)D.cv2.morphologyEx(image,cv2.MORPH_TOPHAT,e)