Local distance preserving autoencoders using continuous kNN graphs

In this paper, we introduce several auto-encoder models that preserve local distances in the latent space. We use a local distance preserving loss that is based on the continuous k-nearest neighbour graph which is known to capture topological features at all scales simultaneously. To improve training performance, we formulate learning as a constraint optimisation problem with local distance preservation as the main objective and reconstruction accuracy as a constraint. We generalise this approach to hierarchical variational auto-encoders thus learning generative models with geometrically consistent latent and data spaces. Our method provides state-of-the-art performance across several standard datasets and evaluation metrics.