We propose to replace vector quantization (VQ) in the latent representation
of VQ-VAEs with a simple scheme termed finite scalar quantization (FSQ), where
we project the VAE representation down to a few dimensions (typically less than
10). Each dimension is quantized to a small set of fixed values, leading to an
(implicit) codebook given by the product of these sets. By appropriately
choosing the number of dimensions and values each dimension can take, we obtain
the same codebook size as in VQ. On top of such discrete representations, we
can train the same models that have been trained on VQ-VAE representations. For
example, autoregressive and masked transformer models for image generation,
multimodal generation, and dense prediction computer vision tasks. Concretely,
we employ FSQ with MaskGIT for image generation, and with UViM for depth
estimation, colorization, and panoptic segmentation. Despite the much simpler
design of FSQ, we obtain competitive performance in all these tasks. We
emphasize that FSQ does not suffer from codebook collapse and does not need the
complex machinery employed in VQ (commitment losses, codebook reseeding, code
splitting, entropy penalties, etc.) to learn expressive discrete
representations.

我们提出使用有限数量标量量化（FSQ）替代 VQ-VAEs 中的向量量化（VQ），通过将 VAE 表示投影到少量维度中，并将每个维度量化为固定值的小集合，从而实现离散表示。我们在图像生成中使用 MaskGIT，以及在深度估计、上色和全景分割中使用 UViM，尽管 FSQ 的设计简单，但在这些任务中获得竞争性表现。我们强调 FSQ 不会出现代码本崩溃问题，也不需要复杂的机制来学习表达丰富的离散表示。