The guide for high quality avatars and AI photography
When building an app for avatars or professional AI photoshoot, you should consider two aspects
- Similarity to the original subject
- High quality generation which look professional
Tracking subject similarity
Make sure to test results on a person you closely know and can judge similarity. Create a list of candidate prompts and run them on 2-3 subjects. For each prompt ask the person to rate how many of the images look similar. Finally sum the ratios for each prompt and compare prompts. Improve the prompts or reconsider a different prompt if similarity is low. Alternatively, consider switching to a different base model to match ethnicity or avoid biased models.
Fine-tuning training tips
- Enable Face-detection in your account settings page - This will augment the training dataset with face-crops from the original training images. This should increase similarity to the subject but can also cause generations to be more toward close-ups instead of nice medium or long shots. In this case you might need to adjust the prompts to use emphasis weights.
- Base model - Select plain SD15 for better resemblance. Select Realistic Vision V5.1 as a base model for nicer pictures. These models are good in realistic results. If you’d like to get generations that are more artistic - consider Deliberate or Reliberate as a base model. For a more diverse ethnically and possibly better similarity to subjects, consider Life Like Ethnicities. Finally, we suggest checking training on SDXL with text-embedding + LoRA.
Prompt generation tips
- Set width and height to 512 x 640 - to match Instagram aspect ratio of 4:5 and also create good portraits. Avoid higher aspect ratios as you might get artifacts such as duplicate heads.
- Enable face-inpainting - This is one of Astria’s unique features and allows creating long shots while avoiding deformed faces.
- Weighted prompts - when a prompt has multiple keywords that collide and reduce similarity - use the parenthesis syntax for emphasis to increase similarity, such as
(ohwx man)On the flip side, try to avoid weighted prompts altogether to preserve similarity to subject.
- Use Controlnet with input image to preserve composition and create unique long-shots. Enable
controlnet_txt2imgif you’d like to create more variation and draw more from the prompt. Increase denoising_strength=1