Diffusion Model

A generative model family that learns to reverse a noise corruption process through many iterative denoising steps.

What It Is

A diffusion model trains on a forward process that gradually adds noise to data, then learns a network that predicts and removes that noise step by step at inference. Each denoising update refines a latent or pixel tensor until a coherent sample appears. The family name covers score-based, variance-preserving, and flow-matching variants that share the iterative denoising loop rather than a single architecture block recipe.

Why It Matters

Diffusion models power many image, audio, and video generators and sit beside autoregressive decoders as a major generative paradigm. Knowing the family separates denoising-based sampling from token-by-token decoding and connects to latent representations and conditioning signals used at each step. The architecture page places diffusion among other model families; this page is the dedicated reference for iterative denoising generators.

Simple Example

A latent diffusion image model starts from Gaussian noise in a compressed latent grid, runs forty denoising steps with a U-Net or transformer denoiser conditioned on a text embedding, then decodes the final latent through a VAE to pixels.

Common Confusions

Diffusion model is a model family and sampling paradigm, not a synonym for any single checkpoint or U-Net shape. Denoising generation describes the iterative output loop; diffusion models are the most common implementation of that loop but not the only one. Diffusion also differs from autoregressive generation: denoising updates the full spatial or channel tensor each step rather than appending one discrete token.

Tags

References

  1. Ho, Jonathan, Ajay Jain, and Pieter Abbeel. "Denoising Diffusion Probabilistic Models." arXiv, 2020, https://arxiv.org/abs/2006.11239.
  2. Ho, Jonathan, and Tim Salimans. "Classifier-Free Diffusion Guidance." arXiv, 2022, https://arxiv.org/abs/2207.12598.