@classmethod
def longitudinalSplit(cls, binary_object):
    """ 分割图片，返回所有字符的起始和结束横坐标 """
    length = binary_object.size[0]
    block = length // 4
    letters = [(0, block), (block + 1, block * 2), (block * 2 + 1, block * 
        3), (block * 3, length)]
    return letters
