With this workflow you can outpaint an image to a standard banner size. Generate multiple standard banner sizes.

1. Drop in an image.

2. Select the banner size you desire from the dropdown.

3. Describe the scene you'd like to fill in. You can use the Negative Prompt box if you wish to remove something from your generations.

4. Choose IPadaptor on/off. Some images benefit from using it and others don't.

5. Load your local models in the purple loader nodes.

This workflow will take any image, at any size, that you wish to use in an online banner ad. Will resize the latent based on the aspect ratio needed.

I set it to generate a bit larger to add more details to the scene and then crop in. Instead of having to crop into your original image, you crop into the outpainted area.