COMiT: Learning Structured Visual Tokens through Sequential Communication
Discrete image tokenizers provide a sequential interface for vision and multimodal models, but are typically optimized for reconstruction or compression and therefore tend to encode local appearance rather than object-level structure. We introduce COMiT, a communication-inspired framework for learning structured discrete visual representations. COMiT constructs a fixed-length latent message through sequential visual observations: at each step, a transformer processes a localized image crop and updates, refines, and reorganizes the existing token sequence. After several iterations, the resulting message conditions a flow-matching decoder that reconstructs the complete image. The encoder and decoder are implemented within a single transformer and trained end-to-end using flow-matching reconstruction and semantic representation-alignment objectives. COMiT substantially improves compositional generalization and relational reasoning over prior methods. Our experiments show that, while semantic alignment helps ground the representation, attentive sequential tokenization is critical for inducing more interpretable, object-centric token structures.