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Max pooling

As explained in Evolutionary Deep Learning: Genetic algorithms and neural networks

Max pooling is a neural-network operation that downsamples local activation regions by retaining their maximum values.

Max pooling downsamples local activation regions by retaining their largest values. In a convolutional neural network, it summarizes feature maps after convolution, reducing noisy and oversized outputs before later layers process them. section 7.1

A practical Keras configuration uses pooling to progressively shrink spatial dimensions:

  • Apply MaxPooling2D((2, 2)) after convolutional layers. section 7.1
  • Use padding="same" when preserving compatible boundary behavior matters. section 7.1
  • Inspect model.summary() to verify the resulting feature-map shapes and parameter counts. section 7.1

Progressive spatial reduction

A CNN can move from 28×28×64 after its first convolution to 14×14×64 after max pooling, then to 7×7×32 and 2×2×16 through successive pooling layers. In an autoencoder, MaxPool layers are added to the encoder to create the funnel or reduction architecture, while UpSampling layers mirror that reduction in the decoder. section 7.1 section 8.2.1

Figure 7.4 Max pooling operation

Shows how maximum pooling reduces the output produced by a convolutional operation. section 7.1

How Evolutionary Deep Learning: Genetic algorithms and neural networks covers it

How deep it goes
Explains the reduction purpose and Keras placement, then stops short of deriving pooling mathematically or examining its learned behavior.
Examples
Uses Fashion-MNIST CNN layers, model summaries, a max-pooling figure, and automatically generated autoencoder gene sequences.
What it assumes
Assumes familiarity with convolutional layers and teaches pooling through their role in reducing convolution outputs.
What you can do after
Operate/configure Keras MaxPooling2D layers and inspect their effect on convolutional model dimensions.
How it connects
Connects max pooling to convolutional neural networks, convolution, feature maps, autoencoders, encoders, decoders, and upsampling.

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Related concepts

This explainer was generated by Manning's knowledge graph from the text of Evolutionary Deep Learning: Genetic algorithms and neural networks. The section links point to the parts of the book it draws on.