Beyond Background Bias: Saliency-Driven Prototype Alignment for Dataset Distillation
Existing diffusion-based dataset distillation methods struggle to balance structural consistency and generalization due to weak alignment between latent prototypes and class-discriminative regions, as well as susceptibility to background interference. This work proposes a saliency-driven two-stage prototype alignment framework that operates without fine-tuning the frozen diffusion backbone (e.g., LDM or DiT). By integrating Grad-CAM to generate high-confidence discriminative regions and introducing a hard prototype refinement strategy to enhance prototype diversity and discriminability, the method leverages only a lightweight classifier to achieve significant improvements over strong baselines across multiple benchmarks. The approach effectively boosts the representativeness, training efficacy, and generalization capability of synthesized data.