title: Using patch from larger image as input dim to Keras CNN gives error 'Tensor' object has no attribute '_keras_history'*
body: <p>I am trying to create a CNN with keras to process 20x20 patches from a larger image of 600x600.</p>
  
  <p>When I attempt the run the code below I receive an error <em>AttributeError: 'Tensor' object has no attribute '_keras_history'</em>  </p>
  
  <p>The below code is only intended to look at the first 20 x 20 patch out of an total of 900, I am trying to get this functioning before attempting to loop through the entire input image. </p>
  
  <p>I don't understand why it is returning the error as each layer is generated with an keras layer and I haven't applied any other operations to the tensor?</p>
  
  <p>I am using tensorflow 1.3 and keras 2.0.6.</p>
  
  <pre><code>nb_filters=16
  
  input_image=Input(shape=(600,600,3))
  Input_1R=Reshape((900,20,20,3))(input_image)
  conv1=Convolution2D(nb_filters,(5,5),activation='relu',padding='valid')(Input_1R[:,0])
  conv4=Convolution2D(1,(6,6),activation='hard_sigmoid',padding='same')(conv1)
  dense6=Dense(1)(conv4)
  output_dense=dense6
  model = Model(inputs=input_image, outputs=output_dense)   
  </code></pre>