Python Deep Learning - Second Edition

Limitations of convolutional networks

Let's start with a quote from professor Hinton himself:

"The pooling operation used in convolutional neural networks is a big mistake and the fact that it works so well is a disaster."

What he means is that the CNNs are translation-invariant. To understand this, let's imagine a picture with a face, located in the right half of the picture. Translation invariance means that a CNN is very good at telling us that the picture contains a face, but it cannot tell us whether the face is in the left or right part of the image. The main culprit for this behavior is the pooling layers. Every pooling layer introduces a little translation invariance. For example, the max pooling routes forward the activation of only ...