~ Efficient-CapsNet ~

This repository has been made for two primarly reasons:

• open source the code (most of) developed during our "first-stage" research on capsules, summarized by the forthcoming article "Efficient-CapsNet: Capsule Network with Self-Attention Routing". The repository let you play with Efficient-CapsNet and let you set the base for your own experiments.
• be an hub and a headlight in the cyberspace to spread to the machine learning comunity the intrinsic potential and value of capsule. However, albeit remarkable results achieved by capsule networks, we're fully aware that they're only limited to toy datasets. Nevertheless, there's a lot to make us think that with the right effort and collaboration of the scientific community, capsule based networks could really make a difference in the long run. For now, feel free to dive in our work :))

1.0 Getting Started

1.1 Installation

Python3 and Tensorflow 2.x are required and should be installed on the host machine following the official guide. Good luck with it!

1. Clone this repository

   git clone https://github.com/EscVM/Efficient-CapsNet.git

2. Install the required packages

   pip3 install -r requirements.txt

Peek inside the requirements file if you have everything already installed. Most of the dependencies are common libraries.

2.0 Efficient-CapsNet Notebooks

The repository provides two starting notebooks to make you confortable with our architecture. They all have the information and explanations to let you dive further in new research and experiments. The first one let you test Efficient-CapsNet over three different datasets. The repository is provided with some of the weights derived by our own experiments. On the other hand, the second one let you train the network from scratch. It's a very lightweight network so you don't need "Deep Mind" TPUs arsenal to train it. However, even if a GP-GPU is not compulsory, it's strongly suggested (No GPU, no deep learning, no party).

3.0 Original CapsNet Notebooks

It goes without saying that our work has been inspiered by Geoffrey Hinton and his article "Dynamic Routing Between Capsules". It's really an honor to build on his idea. Nevertheless, when we did our first steps in the capsule world, we were pretty disappointed in finding that all repositories/implementations were ultimately wrong in some aspects. So, we implemented everything from scratch, carefully following the original Sara's repository. However, our implementation, besides beeing written for the new TensorFlow 2 version, is much more easier and practical to use. Sara's one is really overcomplicated and too mazy that you can lost pretty easily.

As for the previous section we provide two notebooks, one for testing (weights have been derived from Sara's repository) and one for training.

Nevertheless, there's a really negative note (at least for us:)); as all other repositories that you can find on the web, also our one is not capable to achieve the scores reported in their paper. We really did our best, but there is no way to make the network achieve a score greater than 99.64% on MNIST. Exactly for this reason, weights provided in this repository are derived from their repository. Anyway, it's Geoffrey so we can excuse him.

4.0 Capsules Dimensions Perturbation Notebook

The network is trained with a reconstruction regularizer that is simply a fully connected network trained in conjuction with the main one. So, we can use it to visualize the inner capsules reppresentations. In particular, we should expect that a dimension of a digit capsule should learn to span the space of variations in the way digits of that class are instantiated. We can see what the individual dimensions represent by making use of the decoder network and injecting some noise to one of the dimensions of the main digit capsule layer that is predicting the class of the input.

So, we coded a practical notebook in which you can dynamically tweak whichever dimension you want of the capsule that is making the prediction (longest one).

Finally, if you don't have the necessary resources (GP-GPU holy grail) you can still try this interesting notebook out on Colab.

Citation

Use this bibtex if you enjoyed this repository and you want to cite it:

@article{mazzia2021efficient,
  title={Efficient-CapsNet: Capsule Network withSelf-Attention Routing},
  author={Mazzia, Vittorio and Salvetti, Francesco and Chiaberge, Marcello},
  year={2021},
  journal={arXiv preprint arXiv:2101.12491},
}