Incremental learning using conditional adversarial networks

Incremental learning using Deep Neural Networks (DNNs) suffers from catastrophic forgetting. Existing methods mitigate it by either storing old image examples or only updating a few fully connected layers of DNNs, which, however, requires large memory footprints or hurts the plasticity of models. In this paper, we propose a new incremental learning strategy based on conditional adversarial networks. Our new strategy allows us to use memory-efficient statistical information to store old knowledge, and fine-tune both convolutional layers and fully connected layers to consolidate new knowledge. Specifically, we propose a model consisting of three parts, i.e., a base sub-net, a generator, and a discriminator. The base sub-net works as a feature extractor which can be pre-trained on large scale datasets and shared across multiple image recognition tasks. The generator conditioned on labeled embeddings aims to construct pseudo-examples with the same distribution as the old data. The discriminator combines real-examples from new data and pseudo-examples generated from the old data distribution to learn representation for both old and new classes. Through adversarial training of the discriminator and generator, we accomplish the multiple continuous incremental learning. Comparison with the state-of-the-arts on public CIFAR-100 and CUB-200 datasets shows that our method achieves the best accuracies on both old and new classes while requiring relatively less memory storage.