Hey, what’s up? 👋

I’m Jakob, a digital artist, working on AI-generated content (NSFW included) and today I’ll talk about Stable Diffusion upscalers.

Quick links:

  • What are upscaler?
  • Other Upscalers
  • How to use Upscalers?

What are Upscalers on Stable Diffusion?

Upscaler Stable Diffusion is a diffusion-based model that uses AI tools to increase the resolution or size of an image while keeping quality and detail.

It analyzes the image’s pixel values to determine a diffusion rate, which is then used to expand the pixels to a higher resolution.

Here are some Upscaler Stable Diffusion techniques:

  • Stable Diffusion x4 upscaler:

Developed by Robin Rombach and Patrick Esser, this model is intended for research purposes only. Enlarging an image can take 20–40 seconds, and it provides more detailed results with a better texture.

  • SD ultimate upscale

This extension divides an image into equal portions called tiles, then impaints them to build additional detail on that portion of the image at a higher resolution.

  • Multi-diffusion extension

This extension can be used to add intricate details and upscale images. It requires the controlnet extension and the controlnet tile model.

Best Stable Diffusion Upscalers

  • R-ESRGAN 4X+
  • ScuNET
  • ScuNET PSNR
  • SwinIR_4x
  • Nearest
  • Lanczos
  • ESGAN 4x+
  • SUPIR

Click here to check the comparison I made between them.

How To Use Upscalers on Stable Diffusion

The first 7 upscalers are default in the Automatic1111 Stable Diffusion.

To use them:

First, open the Stable Diffusion WebUI:

  1. Go to the ‘Extras’ tab.
  2. Upload the photo you want to upscale.
  3. Select the upscaler in ‘Upscaler 1’, (if you want to mix with another, upload it in ‘Upscale 2’ and adjust the weight).
  4. At the “Scale By” tab, set the proportion you want to increase for example 2x times bigger, and click “Generate”.

You can also select “Scale to” at step 4 and define the final resolution you want.

To use SUPIR, check here.

Want more tools and tutorials? 👉 Subscribe 👈

Don’t forget to check our 🆓 NSFW AI image generator list 🆓