Adversarial Learning of Disentangled and Generalizable Representations of Visual Attributes

Shunting at Arbitrary Feature Levels via Spatial Disentanglement: Toward Selective Image Translation

The past few years have witnessed considerable efforts devoted to translating images from one domain to another, mainly aiming at editing global style. Here, we focus on a more general case, selective image translation (SLIT), under an unsupervised setting. SLIT essentially operates through a shunt mechanism that involves learning gates to manipulate only the contents of interest (CoIs), which can be either local or global, while leaving the irrelevant parts unchanged. Existing methods typically rely on a flawed implicit assumption that CoIs are separable at arbitrary levels, ignoring the entangled nature of DNN representations. This leads to unwanted changes and learning inefficiency. In this work, we revisit SLIT from an information-theoretical perspective and introduce a novel framework, which equips two opposite forces to disentangle the visual features. One force encourages independence between spatial locations on the features, while the other force unites multiple locations to form a "block" that jointly characterizes an instance or attribute that a single location may not independently characterize. Importantly, this disentanglement paradigm can be applied to visual features of any layer, enabling shunting at arbitrary feature levels, which is a significant advantage not explored in existing works. Our approach has undergone extensive evaluation and analysis, confirming its effectiveness in significantly outperforming the state-of-the-art baselines.

FragNet, a Contrastive Learning-Based Transformer Model for Clustering, Interpreting, Visualizing, and Navigating Chemical Space

The question of molecular similarity is core in cheminformatics and is usually assessed via a pairwise comparison based on vectors of properties or molecular fingerprints. We recently exploited variational autoencoders to embed 6M molecules in a chemical space, such that their (Euclidean) distance within the latent space so formed could be assessed within the framework of the entire molecular set. However, the standard objective function used did not seek to manipulate the latent space so as to cluster the molecules based on any perceived similarity. Using a set of some 160,000 molecules of biological relevance, we here bring together three modern elements of deep learning to create a novel and disentangled latent space, viz transformers, contrastive learning, and an embedded autoencoder. The effective dimensionality of the latent space was varied such that clear separation of individual types of molecules could be observed within individual dimensions of the latent space. The capacity of the network was such that many dimensions were not populated at all. As before, we assessed the utility of the representation by comparing clozapine with its near neighbors, and we also did the same for various antibiotics related to flucloxacillin. Transformers, especially when as here coupled with contrastive learning, effectively provide one-shot learning and lead to a successful and disentangled representation of molecular latent spaces that at once uses the entire training set in their construction while allowing "similar" molecules to cluster together in an effective and interpretable way.