🤖 AI Summary
Conditional diffusion models suffer from conditional mismatch under imprecise supervision—e.g., noisy, blurry, or missing labels—leading to degraded generation quality. This work presents the first systematic study of imprecise supervision in diffusion models and proposes DMIS, a robust training framework. DMIS decouples the generative objective from the classification objective, introduces a diffusion-based classifier to explicitly model class posterior distributions, and designs an optimized timestep sampling strategy to enhance posterior inference efficiency; its objective is formulated via likelihood maximization. Experiments demonstrate that DMIS consistently generates high-fidelity, class-discriminative samples across diverse tasks—including image synthesis, weakly supervised learning, and noisy data distillation—while significantly improving robustness to label noise compared to standard conditional diffusion baselines.
📝 Abstract
Conditional diffusion models have achieved remarkable success in various generative tasks recently, but their training typically relies on large-scale datasets that inevitably contain imprecise information in conditional inputs. Such supervision, often stemming from noisy, ambiguous, or incomplete labels, will cause condition mismatch and degrade generation quality. To address this challenge, we propose DMIS, a unified framework for training robust Diffusion Models from Imprecise Supervision, which is the first systematic study within diffusion models. Our framework is derived from likelihood maximization and decomposes the objective into generative and classification components: the generative component models imprecise-label distributions, while the classification component leverages a diffusion classifier to infer class-posterior probabilities, with its efficiency further improved by an optimized timestep sampling strategy. Extensive experiments on diverse forms of imprecise supervision, covering tasks of image generation, weakly supervised learning, and noisy dataset condensation demonstrate that DMIS consistently produces high-quality and class-discriminative samples.