免蒸馏，只改一个Loss！5行代码实现扩散模型4步生成

TL;DR - Perceptual Flow Matching replaces MSE with a semantic perceptual loss to generate images and videos in 4–8 steps, approaching the quality of conventional 35–50-step flow-matching models without distillation or teacher models.

• Perceptual supervision penalizes off-manifold predictions, reducing the posterior-mean blurring that accumulates during few-step inference.
• The method was evaluated on text-to-image generation, image editing, and video generation.
• Experiments link stronger off-manifold discrimination in feature spaces such as DINO and SigLIP to better few-step generation.
• Huber, pixel-space, and randomly initialized ViT losses did not provide the same gains, indicating that semantically rich supervision spaces are essential.