Combining OMG with InstantID for multi-concept generation

[yunbinmo]

Hi, thanks for the amazing job and I would like to ask what is the exact approach of using OMG with InstantID for multi-concept generation? I understand that you have the inference code available but I don't quite understand what it is doing.

As I know, the architecture of InstantID only takes in one input reference image, it would be good if I can get a high-level view of how you combine OMG with InstantID for multi-concept generation when there are more than one reference images, thank you!

[yzhang2016]

InstantID can take multiple images as reference. The embeddings of all reference images are averaged as the input of the identity net (control net).

[yzhang2016]

The key idea is the two-stage generation and the noise blending.

Why two-stage?

• For finetuned SDXL or SDXL + Lora weights, the concept composition ability or text-image alignment are worse than the original SDXL. Hence, we use the original SDXL to generate the content and layout in the first stage and collect intermediate information such as attention maps and noises for noise blending in the second stage.

How to combine with InstantID or ID LoRAs

• Our OMG framework can be combined with other single ID personalization methods, not only InstantID and LoRAs. Noise blending takes the regional personlized noises of multiple IDs and composite a fused one. The regions can be detected using the generated image in the first stage.
• Blending in the latent space is much better than blending in pixel space, which can avoid illumiation disharmony and artifacts around the edges.

[yunbinmo]

I see! Thanks for the reply!

But I have one more question, if embeddings of multiple images are averaged as an input to the identityNet, would we expect some kind of mixture of facial features from different IDs?

In other words, the performance of using an average of 3 ID image embeddings would look worse than using an average of 2 ID image embeddings, is that generally the case?

[tanghengjian]

i guess:
1、3 ID or 2 ID, may not the OMG's scope
2、averaged 3 ID face imbedings extracted by insight face may has been implied by instantid?

[tanghengjian]

hi, @yzhang2016 we tested that, the first stage's person face area will limit the second stage's user face generation, in other word, we found less face similarity in some case.
can we make an adaptive similar face with user's face in stage 1, utilize adapter faceID ?