After training the network, we can use it (recalling phase) in a recognition task...

Real-world applications cannot avoid noise. However, neural networks recognize noisy input patterns thanks to generalization of the training patterns. Next figure shows a noisy six clearly recognized.

Neural networks are robust in the presence of noise, but there is always a limit...
This example shows a highly noisy pattern, which can be considered
either as a corrupted 5 or 6;
the network is unable to
correctly classify the input, however, neither can a human observer.

Version 16.I.96