Closed-form sample probing for training generative models in zero-shot learning

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2022-2-10
Çetin, Samet
Generative modeling based approaches have led to significant advances in generalized zero-shot learning over the past few-years. These approaches typically aim to learn a conditional generator that synthesizes training samples of classes conditioned on class embeddings, such as attribute based class definitions. The final zero-shot learning model can then be obtained by training a supervised classification model over the real and/or synthesized training samples of seen and unseen classes, combined. Therefore, naturally, the generative model ideally needs to produce not only relevant samples, but also those that are sufficiently informative for classifier training purposes. However, existing approaches rely on approximations or heuristics to enforce the generator to produce class-specific samples. In this thesis, we propose a principled approach that shows how to directly maximize the value of training examples for zero-shot model training purposes, by inferring and evaluating the closed-form ZSL models at each generative model training step, which we call sample probing. This approach provides a way to validate the quality of generated samples in an end-to-end manner, where the generator receives feedback directly based on the prediction made on the real samples of unseen classes. Our experimental results show that sample probing improves the recognition results when integrated into state-of-the-art baselines.

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Citation Formats
S. Çetin, “Closed-form sample probing for training generative models in zero-shot learning,” M.S. - Master of Science, Middle East Technical University, 2022.