Learning to Quantize for Training Vector-Quantized Networks

Deep neural networks incorporating discrete latent variables have shown significant potential in sequence modeling. A notable approach is to leverage vector quantization (VQ) to generate discrete representations within a codebook. However, its discrete nature prevents the use of standard backpropagation, which has led to challenges in efficient codebook training. In this work, we introduce Meta-Quantization (MQ), a novel vector quantization training framework inspired by metalearning. Our method separates the optimization of the codebook and the auto-encoder into two levels. Furthermore, we introduce a hyper-net to replace the embedding-parameterized codebook, enabling the codebook to be dynamically generated based on the feedback from the auto-encoder. Different from previous VQ objectives, our innovation results in a meta-objective that makes the codebook training task-aware. We validate the effectiveness of MQ with VQVAE and VQ-GAN architecture on image reconstruction and generation tasks. Experimental results showcase the superior generative performance of MQ, underscoring its potential as a robust alternative to existing VQ methods.