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ControlNet

proper nounAlso: control net, zero convolution, T2I-Adapter, IP-Adapter

In plain wordsAn add-on for image generators that makes them follow a guide image — a sketch, a stick-figure pose or a depth map — so the layout comes out as intended.

  1. A method for steering a pretrained text-to-imagetext-to-image model, n.: An AI system that creates a picture from a written description, such as 'a fox reading a newspaper, in watercolor', usually within seconds. diffusion modeldiffusion model, n.: An AI that learns to create images, sound or video by practicing noise removal: shown pictures buried under static, it learns to clean them up, then builds new ones starting from pure static. with a guide image that fixes the layout, while the original network stays untouched. The base model is frozen; a trainable duplicate of its encoder takes the guide — a human-pose skeleton, a depth or segmentation map, an edge map, a scribble — and adds its features to the frozen network's skip connections and middle block through 1 × 1 convolutions whose weights and biases are initialized to zero ('zero convolutions'). These contribute nothing at first, so the combined model starts out behaving exactly like the original and control is phased in only as training finds useful weights, which keeps early noisy gradients from damaging the pretrained backbone. Training works with under 50,000 conditioning pairs or over a million. Separate ControlNets can be stacked and combined with fine-tunes such as LoRAlow-rank adaptation, n.: A cheap way to customize a big AI model: instead of changing all its billions of numbers, you train a small add-on of a few million numbers that slightly adjusts how it behaves., and they made pose- and layout-faithful generation routine in the Stable DiffusionStable Diffusion, prop. n.: A widely used image-generating AI whose model files were released for anyone to download, so people could run it on their own computers and adapt it. ecosystem. Lighter adapters, such as T2I-Adapter and IP-Adapter for reference images, follow similar ideas.

    Feed the pose skeleton through ControlNet and all four dancers land exactly where you drew them.

Origin

Introduced by Lvmin Zhang, Anyi Rao and Maneesh Agrawala of Stanford University in 'Adding Conditional Control to Text-to-Image Diffusion Models' (posted February 2023; ICCV 2023, where it was one of two papers awarded the Marr Prize for best paper), with open-source models for Stable Diffusion 1.5 that spread rapidly.

Related

See also
  • Stable DiffusionStable Diffusion, prop. n.: A widely used image-generating AI whose model files were released for anyone to download, so people could run it on their own computers and adapt it.
  • diffusion modeldiffusion model, n.: An AI that learns to create images, sound or video by practicing noise removal: shown pictures buried under static, it learns to clean them up, then builds new ones starting from pure static.
  • image-to-image translationimage-to-image translation, n.: Turning one picture into another version of itself — a sketch into a photo, a day scene into night, a horse into a zebra — while keeping its layout.
  • pose estimationpose estimation, n.: Working out the position and orientation of something from images: where a person's joints are and how their body is posed, or exactly how an object or camera is placed and turned in space.
  • depth estimationdepth estimation, n.: Working out how far away each point in a scene is from the camera, producing a 'depth map' that turns a flat picture into a sense of near and far.
  • DreamBoothDreamBooth, prop. n.: A way to teach an image generator one specific subject — your dog, your face, a product — from a handful of photos, so it can draw that exact subject in new scenes.
  • low-rank adaptationlow-rank adaptation, n.: A cheap way to customize a big AI model: instead of changing all its billions of numbers, you train a small add-on of a few million numbers that slightly adjusts how it behaves.

Sources

  1. Zhang, L., Rao, A. & Agrawala, M. (2023). Adding Conditional Control to Text-to-Image Diffusion Models. ICCV 2023. arXiv:2302.05543. arxiv.org/abs/2302.05543

Mentioned in

AI artAI art, n.: Images, music or other artworks made with the help of AI — from early computer drawing programs to today's prompt-based image generators — and the debate over whether and how such work counts as art., Stable DiffusionStable Diffusion, prop. n.: A widely used image-generating AI whose model files were released for anyone to download, so people could run it on their own computers and adapt it., text-to-image modeltext-to-image model, n.: An AI system that creates a picture from a written description, such as 'a fox reading a newspaper, in watercolor', usually within seconds., image-to-image translationimage-to-image translation, n.: Turning one picture into another version of itself — a sketch into a photo, a day scene into night, a horse into a zebra — while keeping its layout.