title: matplotlib can't open *.jpg file
body: <p>I have *.jpg images in a directory "dogs" and I can access the first one as below:</p>
  
  <pre><code>import os
  os.chdir(os.path.expanduser('~/fastai/data/dogscats'))
  cwd=os.getcwd()
  dog=os.listdir(os.path.join(cwd,'valid/dogs'))[0]
  print (dog)
  
  dog.5535.jpg
  </code></pre>
  
  <p>the problem is when I try to plot the image with matplotlib it can't 
  locate the image:</p>
  
  <pre><code>%matplotlib inline
  import matplotlib.pyplot as plt
  plt.imread(dog)
  
  FileNotFoundError: [Errno 2] No such file or directory: 'dog.5535.jpg'
  </code></pre>
  
  <p>I tried opening the dog with pillow but it gives the same error.</p>
  
  <p>however, I can read 'dog.5535.jpg' if I place the image on my desktop and give that path to <code>plt.imread()</code>.  Am I missing something?</p>
  
  <p>Thanks</p>