ing nested, hierarchical representations of data. Deep feed-forward neural networks are the typical example of deeplearning models. Convolutional Neural Networks (CNN) in-clude convolutional operations over the input and are de-signed speciﬁcally for vision tasks. Convolutional ﬁlters areuseful for encoding translation invariance, a key concept fordiscovering useful features in images (Bouvrie 2006).