title: Trying to Generate Random Picture with PIL, but get strange result
body: <p><a href="https://i.stack.imgur.com/lY81n.jpg" rel="nofollow noreferrer">Generated Pictured</a></p>
  
  <p>I used this code to generate a random picture by filling out each pixel, but why I got this strange output (picture at the above link)? There are parallel red, green, blue vertical lines in the picture.</p>
  
  <pre><code>#&lt;Python 3.8&gt;
  from PIL import Image
  import numpy as np
  data=np.random.randint(low=0,high=256,size=128*128*3)
  data=data.reshape(128,128,3)
  Image.fromarray(data,'RGB')
  </code></pre>