title: Can't reshape array with numpy
body: <p>i want to change a image(17x15) to 2d array with code:</p>
  
  <pre><code>from PIL import Image
  import numpy as np
  
  list = []
  im = Image.open('plus1.jpg')
  row,col =  im.size
  print(row,col)
  for i in range (row):
     for j in range (col):
          r, g, b = im.getpixel((i, j))
          list.append([r,g,b]) 
  print(list)
  print(len(list))
  list = np.array(list)
  print(list)
  list.reshape(17,15)
  </code></pre>
  
  <p>It change okay to 1D array but when i using reshape to make 2D array with <code>list.reshape(17,15)</code> got the error:</p>
  
  <pre><code>ValueError: total size of new array must be unchanged
  </code></pre>
  
  <p>The size is 17x15, and change to 1D array have 255 elements, so why the error appear and how to make it run normaly?</p>