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MERL · Research Intern · May – Aug 2022

Steered Diffusion

A general framework steers pretrained diffusion models during sampling for image-to-image and label-conditioned generation.

Energy-based diffusion steering

Steered Diffusion turns a pretrained diffusion generator into a conditional generator at inference time. A pretrained inverse model defines a loss for the requested condition, and that loss steers the denoising trajectory toward an image that satisfies it.

For example, an inverse model can estimate a semantic label or a degraded observation from the current image. Comparing that prediction with the desired condition supplies a guidance signal.

Steered Diffusion examples for inpainting and semantic generation

How it works

  1. Choose a pretrained diffusion generator and an auxiliary model that represents the desired task or condition.
  2. Construct a task loss that measures agreement with the input condition during sampling.
  3. Use the guidance signal to steer denoising, adapting the generator to the task without training a separate task-specific generator.

Results

The framework supports image-to-image and label-conditioned synthesis within the same plug-and-play formulation.

The paper demonstrates tasks including inpainting, colorization, super-resolution and semantic generation. The slide shows inpainting and semantic-generation samples.

Contributions

  • Introduced the first plug-and-play framework applicable to both image-to-image translation and label-conditioned synthesis in the studied setting.
  • Used pretrained auxiliary networks and energy-based guidance to express new conditions at inference time.
  • Supported tasks including inpainting, colorization, super-resolution and semantic generation without task-specific generator training.

Steered Diffusion: A Generalized Framework for Plug-and-Play Conditional Image Synthesis. ICCV 2023.