Continuous Speculative Decoding for Autoregressive Image Generation
Continuous autoregressive visual generation models suffer from high inference latency, while existing speculative decoding methods are restricted to discrete token spaces and lack theoretical foundations or practical techniques for continuous-valued outputs. Method: This work pioneers the extension of speculative decoding to continuous visual generation. We propose a diffusion-prior-based continuous acceptance criterion, design a denoising trajectory alignment mechanism and token pre-filling strategy to mitigate distribution mismatch, and establish a continuous accept-reject sampling framework with analytically derived upper bounds on approximation error. Contribution/Results: Our approach achieves a 2.33× inference speedup on standard diffusion-based autoregressive models while provably preserving the exact output distribution of the original model. The implementation is publicly available.