title: Issue using patchify library to open image files.,
body: <p>I was trying to stitch smaller patches of images into one large image using the patchify library and the code used by DigitalSreeni on Youtube in episode 208 of multiclass semantic segmentation. However when using the below piece of code, i wasn't able to open the image files from the very beginning. It asked me to take a look at the directory or the file itself, but i knew the directory was correct. Code and error has been attached below.</p>
  <pre><code>from patchify import patchify, unpatchify
  
  large_image = cv2.imread(&quot;Users/anish/largeimages/largeimage.png&quot;, 0)
  #This will split the image into small images of shape [3,3]
  patches = patchify(large_image, (128, 128), step=1)
  </code></pre>
  <p>Error shown on command prompt:</p>
  <pre><code>from patchify import patchify, unpatchify
  
  large_image = cv2.imread(&quot;Users/anish/largeimages/largeimage.png&quot;, 0)
  #This will split the image into small images of shape [3,3]
  patches = patchify(large_image, (128, 128), step=1)
  Traceback (most recent call last):
  
    File &quot;C:\Users\anish\AppData\Local\Temp\ipykernel_23432\463661116.py&quot;, line 5, in &lt;module&gt;
      patches = patchify(large_image, (128, 128), step=1)
  
    File &quot;C:\Users\anish\anaconda3\envs\py37gpu\lib\site-packages\patchify\__init__.py&quot;, line 32, in patchify
      return view_as_windows(image, patch_size, step)
  
    File &quot;C:\Users\anish\anaconda3\envs\py37gpu\lib\site-packages\patchify\view_as_windows.py&quot;, line 21, in view_as_windows
      raise TypeError(&quot;`arr_in` must be a numpy ndarray&quot;)
  
  TypeError: `arr_in` must be a numpy ndarray
  
  
  [ WARN:0@9.588] global D:\a\opencv-python\opencv-python\opencv\modules\imgcodecs\src\loadsave.cpp (239) cv::findDecoder imread_('Users/anish/largeimages/largeimage.png'): can't open/read file: check file path/integrity
  </code></pre>