title: Why the weight of CNN from keras is only one-dimensional?
body: <p>I built a CNN using <code>keras</code> and saved the weight in a *.hdf file. I used <code>16</code> filters and the size of the kernel is <code>3×3</code>. 
  But the output of <code>save_weight</code> for the first <code>Convolution2D</code> is only <code>1×16</code>. The size of kernel is <code>3×3</code>, so the output should be <code>3×3×16</code>, shouldn't it? Why does the output behave like this?</p>
  
  <p>This is the screenshot of the structure of *.hdf file:</p>
  
  <p><img src="https://i.stack.imgur.com/FDlBw.png" alt=""></p>