使用Python将屏幕截图保存在数组中

我如何使用python、mss和opencv来捕捉我的电脑屏幕，并将其保存为一个图像阵列，形成一部电影？我正在转换为灰度，所以它可以是一个3维数组。我想把每个二维屏幕截图存储在一个三维数组中，以便查看和处理。我很难构建一个数组来保存屏幕截图的序列，并在cv2中播放屏幕截图的序列。

import time
import numpy as np
import cv2
import mss
from PIL import Image
with mss.mss() as sct:
    fps_list=[]
    matrix_list = []
    monitor = {'top':40, 'left':0, 'width':800, 'height':640}
    timer = 0
    while timer <100:
        last_time = time.time()
        #get raw pizels from screen and save to numpy array
        img = np.array(sct.grab(monitor))
        img=cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
        #Save img data as matrix
        matrix_list[timer,:,:] = img
        #Display Image
        cv2.imshow('Normal', img)
        fps = 1/ (time.time()-last_time)
        fps_list.append(fps)
        #press q to quit
        timer += 1
        if cv2.waitKey(25) & 0xFF == ord('q'):
            cv2.destroyAllWindows()
            break
#calculate fps
fps_list = np.asarray(fps_list)
print(np.average(fps_list))
#playback image movie from screencapture
while t < 100:
    cv.imshow('Playback',img_matrix[t])
    t += 1