title: How to properly use numpy in keras
body: <p><strong>the question is:</strong></p>
  
  <p>In the keras tutorial it use an input x_train = np.random.random((100, 100, 100, 3)), it should means that there's 100 images each has size of [100,100,3] right?</p>
  
  <p>So i thought that x_train[0][0] should represent the first channel of the first img (which should be [100, 100]), but x_train[0][0] in fact has a size of [100,3]... so i'm confused, how can keras take this [100,100,100,3] numpy array as a set of imgs? please help me out, thank in advance.</p>
  
  <p>Another question is:
  how can I construct a input like this ? Cause when I do np.array([[100,100],[100,100]]), it becomes to array of [2,100,100]</p>