Pooling

Deep in the network after multiple Convolution layers the number of features quickly grows. To reduce the amount of features we can summarize them with a Pooling Operation.

It works like this:

Notice that the stride is usually bigger than with Convolution.

The example above shows one possible pooling function. But there are other commonly used functions:

  • Maximum
  • Average
  • - Norm → all values squared and summed up.

Combining Convolution and Pooling can lead to a network looking like this: