One-Step Diffusion with Distribution Matching Distillation

Abstract

Diffusion models generate high-quality images but require dozens of forward passes. We introduce Distribution Matching Distillation (DMD) a procedure to transform a diffusion model into a one-step image generator with minimal impact on image quality. We enforce the one-step image generator match the diffusion model at distribution level by minimizing an approximate KL divergence whose gradient can be expressed as the difference between 2 score functions one of the target distribution and the other of the synthetic distribution being produced by our one-step generator. The score functions are parameterized as two diffusion models trained separately on each distribution. Combined with a simple regression loss matching the large-scale structure of the multi-step diffusion outputs our method outperforms all published few-step diffusion approaches reaching 2.62 FID on ImageNet 64x64 and 11.49 FID on zero-shot COCO-30k comparable to Stable Diffusion but orders of magnitude faster. Utilizing FP16 inference our model can generate images at 20 FPS on modern hardware.