title: cant save an 4d array int .txt file
body: <p>I am using the sliding window technic to an image and i am extracting the mean values of pixels of each one window. So the results are someting like this [[[[215.015625][123.55036272][111.66057478]]]].now the question is how could i save all these values for every one window into a txt file or at a CSV because  i want to use them for further compare similarities? whatever i tried the error is same..that it is a 4D array and not an 1D or 2D. I ll appreciate any help really.! Thank you in advance </p>
  
  <pre><code>import cv2
  import matplotlib.pyplot as plt
  import numpy as np
  
  
  # read the image and define the stepSize and window size
  # (width,height)
  image2 = cv2.imread("bird.jpg")# your image path
  
  image = cv2.resize(image2, (224, 224))
  tmp = image  # for drawing a rectangle
  stepSize = 10
  (w_width, w_height) = (60, 60 )  # window size
  for x in range(0, image.shape[1] - w_width, stepSize):
      for y in range(0, image.shape[0] - w_height, stepSize):
          window = image[x:x + w_width, y:y + w_height, :]
  
          # classify content of the window with your classifier and
          # determine if the window includes an object (cell) or not
          # draw window on image
          cv2.rectangle(tmp, (x, y), (x + w_width, y + w_height), (255, 0, 0), 2)  # draw rectangle on image
          plt.imshow(np.array(tmp).astype('uint8'))
          # show all windows
          plt.show()
          mean_values=[]
          mean_val, std_dev = cv2.meanStdDev(image)
          mean_val = mean_val[:3]
          mean_values.append([mean_val])
          mean_values = np.asarray(mean_values)
          print(mean_values)
  </code></pre>