title: Resizing an input image in a Keras Lambda layer
body: <p>I would like my <code>keras</code> model to resize the input image using OpenCV or similar.</p>
  <p>I have seen the use of <code>ImageGenerator</code>, but I would prefer to write my own generator and simply resize the image in the first layer with <code>keras.layers.core.Lambda</code>.</p>
  <p>How would I do this?</p>