  We present SEED, an elaborate image tokenizer that empowers Large Language
Models (LLMs) with the emergent ability to SEE and Draw at the same time.
Research on image tokenizers has previously reached an impasse, as frameworks
employing quantized visual tokens have lost prominence due to subpar
performance and convergence in multimodal comprehension (compared to BLIP-2,
etc.) or generation (compared to Stable Diffusion, etc.). Despite the
limitations, we remain confident in its natural capacity to unify visual and
textual representations, facilitating scalable multimodal training with LLM's
original recipe. In this study, we identify two crucial principles for the
architecture and training of SEED that effectively ease subsequent alignment
with LLMs. (1) Image tokens should be independent of 2D physical patch
positions and instead be produced with a 1D causal dependency, exhibiting
intrinsic interdependence that aligns with the left-to-right autoregressive
prediction mechanism in LLMs. (2) Image tokens should capture high-level
semantics consistent with the degree of semantic abstraction in words, and be
optimized for both discriminativeness and reconstruction during the tokenizer
training phase. As a result, the off-the-shelf LLM is able to perform both
image-to-text and text-to-image generation by incorporating our SEED through
efficient LoRA tuning. Comprehensive multimodal pretraining and instruction
tuning, which may yield improved results, are reserved for future
investigation. This version of SEED was trained in 5.7 days using only 64 V100
GPUs and 5M publicly available image-text pairs. Our preliminary study
emphasizes the great potential of discrete visual tokens in versatile
multimodal LLMs and the importance of proper image tokenizers in broader
research.
