python openCV2 imread () 方法报错:expected string or Unicode object, bool found

UI自动化中,我使用openCV封装了一个方法用于获取元素坐标,然后使用appium的tap方法进行点击,运行过程中imread的方法出现报错:expected string or Unicode object, bool found,小白尚未找到原因及解决方法,麻烦社区的大大帮忙看下。。。。
话不多说,下面是我的代码:

自定义图片名称,并使用appium的截图方法获取一张截图,返回图片路径
import cv2
import logging
import time
import os

  # 封装appium截图的方法
    def get_screen_shot(self, name=None):
        try:
            if name is None:
                image = self.driver.save_screenshot('/Users/alex.pan/Documents/test/default.png')
                return image
            elif name is not None:
                image = self.driver.save_screenshot(name)
                return image
        except Exception:
            raise

    def get_original_image(self, name):
        """
        获取素材原图,返回图片路径
        :param name:
        :return:
        """
        picture_name = self.picture_name(name)
        image = self.get_screen_shot(picture_name)
        return image

    @staticmethod
# 自定义图片名称
    def picture_name(name):
        data = time.strftime('%Y-%m-%d', time.localtime(time.time()))
        tm = time.strftime('%Y-%m-%d_%H_%M_%S', time.localtime(time.time()))
        pic_type = '.png'
        file_path = '/Users/alex.pan/Documents/test' + '/' + data
        if os.path.exists(file_path):
            filename = file_path + '/' + name + '_' + tm + pic_type
            print filename
            return filename
        else:
            os.makedirs(file_path)
            filename = file_path + '/' + name + '_' + tm + pic_type
            print filename
            return filename

  # open cv 获取元素坐标的方法
@staticmethod
    def get_coordinates_by_open_cv(original_image_name, temple_img, method=cv2.TM_CCOEFF_NORMED):
        # 实时截一张图作为原图
        # 调用APPIUM的方法截图,并返回保存路径
        original_image = self.get_original_image(original_image_name)

        # 输入模板图路径
        target_image = temple_img
        # 读取图片,并将图片转化为灰度
        read_original_image = cv2.imread(original_image, 0)
        read_target_image = cv2.imread(target_image, 0)
        find_height, find_width = read_target_image.shape[::]

        # 进行图像匹配
        result = cv2.matchTemplate(read_original_image, read_target_image, method)
        min_val, max_val, min_loc, max_loc = cv2.minMaxLoc(result)
        logging.info(min_val, max_val, min_loc, max_loc)

        # 计算点坐标
        # point_up_left = max_loc
        # point_low_right = (max_loc[0] + find_width, max_loc[1] + find_height)
        point_centre = (max_loc[0] + (find_width / 2), max_loc[1] + (find_height / 2))

        print point_centre
        return point_centre

运行后报错
File “/Users/alex.pan/Documents/test/demo.py”, line 144, in get_coordinates_by_open_cv
read_original_image = cv2.imread(original_image_name, 0)
TypeError: expected string or Unicode object, bool found

发现问题:我把original_image_name这个参数直接替换成图片路径这个方法是执行成功的,但是使用appium实时截图后返回路径的方法后就报错了

read_original_image = cv2.imread(original_image_name, 0)