Dynamic Routing Between Capsules

NeurIPS 2017  Â·  Sara Sabour, Nicholas Frosst, Geoffrey E. Hinton ·

A capsule is a group of neurons whose activity vector represents the instantiation parameters of a specific type of entity such as an object or an object part. We use the length of the activity vector to represent the probability that the entity exists and its orientation to represent the instantiation parameters. Active capsules at one level make predictions, via transformation matrices, for the instantiation parameters of higher-level capsules. When multiple predictions agree, a higher level capsule becomes active. We show that a discrimininatively trained, multi-layer capsule system achieves state-of-the-art performance on MNIST and is considerably better than a convolutional net at recognizing highly overlapping digits. To achieve these results we use an iterative routing-by-agreement mechanism: A lower-level capsule prefers to send its output to higher level capsules whose activity vectors have a big scalar product with the prediction coming from the lower-level capsule.

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Datasets


Introduced in the Paper:

MultiMNIST

Used in the Paper:

CIFAR-10 MNIST EMNIST smallNORB

Results from the Paper


Task Dataset Model Metric Name Metric Value Global Rank Result Benchmark
Image Classification CIFAR-10 ensemble of 7 models Percentage correct 89.4 # 191
Image Classification EMNIST-Balanced TextCaps Accuracy 90.46 # 4
Image Classification MNIST CapsNet Percentage error 0.25 # 10
Image Classification MultiMNIST CapsNet Percentage error 5.2 # 1
Image Classification smallNORB CapsNet Classification Error 3.77 # 6

Methods