HumanFlow: Controllable Human Image Generation via Flow Matching

摘要

We present HumanFlow, a unified flow-matching-based framework that enables high-fidelity and controllable full-body human image generation under diverse human-centric control conditions. Despite recent progress, controllable human image generation poses a fundamental challenge in balancing high visual fidelity with strict adherence to human-centric control conditions. HumanFlow formulates human image generation as a conditional flow-matching process with deterministic generation dynamics. To incorporate such human-centric control conditions into the pretrained model, we introduce a unified control framework with Control Encoder and Token-ControlNet. A Control Encoder maps diverse conditions into a unified latent representation that is spatially aligned with the image latent space. Token-ControlNet is a lightweight control network architecturally aligned with the FLUX double-stream design. To address accurate structural control over human bodies, we further propose the Human Topology Consistency Loss (HTCL). HTCL regularizes conditional flow matching by constraining generated human configurations to a union of statistically grounded topology manifolds defined by normalized bone ratios and joint angles. To support large-scale training and systematic evaluation, we construct MiCoGen, a multi-condition human image dataset comprising over one million full-body human images with aligned text descriptions and rich human-centric control conditions. Extensive quantitative and qualitative evaluations on the MiCoGen dataset show that HumanFlow consistently achieves improved structural consistency than the existing diffusion-based and flow-matching-based methods, while maintaining high visual fidelity.