Preprint Open access
CAST: Causal Advantage-Structured Training with Spatially Grounded Compositional Rewards for Diffusion Models
Online reinforcement learning has been extended to flow matching for diffusion model (DM) image generation. However, this paradigm faces three limitations: (1) Window selection. Existing methods manually set the stochastic differential equation (SDE) sampling window, i.e., the denoising steps where exploration noise is …