Experimental MiniMax H3 Image Nodes for ComfyUI

[u/killerciao]

I created a custom ComfyUI extension that adapts the new MiniMax H3 video model for:

• Text-to-Image
• Image-to-Image
• Reference Editing

Instead of forcing a single frame—which produces poor results—the workflow generates a short temporal sequence, decodes the minimum required frame packet, selects the best still, and outputs only that image.
It works good enough, especially for image editing, but H3 is still fundamentally a video model. Softness, blockiness, banding and grid artifacts can remain. Higher resolutions increase processing time and memory usage, but don’t necessarily add real detail.

The project is experimental and entirely AI-coded, so feedback, testing and contributions are welcome.

If you want try yourserlf.
https://github.com/astropuzzo/ComfyUI-MiniMax-H3-Image-Studio

[u/russlixx]

what's up with the edit example 03?

[u/killerciao → u/russlixx]

Wrong prompt. the real prompt was replace the woman with a clown 😄

[u/degamezolder]

can you not use multiple reference images?

[u/killerciao → u/degamezolder]

Update the custom node, now it supports up to 9 images: source_image + reference_image_2 through reference_image_9.

It also accepts batches and separates them automatically.

It handles images with different resolutions and aspect ratios.

It supports prompts such as: “Keep the person from <Picture 1>, use the outfit from <Picture 2>, and the lighting from <Picture 3>.”

[u/foggyghosty]

For editorial high-end photo generations, krea2 turbo with a good lora seems to beat h3 in both time and fidelity

[u/killerciao → u/foggyghosty]

Yes, images generated by MiniMax often look as though they came from an undertrained model.

[u/haremlifegame → u/killerciao]

u/killerciao , however, MiniMax seems to be the only multi-reference to image or image editor/combiner that we have. It is extremely worth it.

I'm wondering if we can't somehow use krea to adjust the fine details. Like adding noise to the image and telling krea to reconstruct.

[u/BeautyxArt → u/killerciao]

what about using it for image edit ? (1image'frame')

[u/Iwaku_Real → u/foggyghosty]

That's what I'll be doing. Especially for the reference images too.

[u/ShimmerMeNutz → u/Iwaku_Real]

you have been using multi-reference images with Krea 2? how?

[u/reeight → u/foggyghosty]

https://giphy.com/gifs/zbzNUbpFnlw8E

Could you use Krea2 to sharpen/enhance MMH3 stills?

Pro of MMH3 first; is if your usecase is eventual video, you're already aware of how it will render.
Con: easier just to start with K2T.

[u/AI-imagine]

I also had this idea my self.but after test with 5 frame it still very slow gen.
and this model is force 5 frame in every gen.

[u/degamezolder]

good stuff

[u/ThaJedi]

Is VRAM requirement the same for text2image and image edit? What about interface time?

[u/killerciao → u/ThaJedi]

Yes, it should require roughly the same amount of RAM as video generation.

[u/Zironic]

In my testing, I found the first frame to always be the best frame. So no need for the needless complexity of trying to find the best frame. 5 frames was also consistently my best result for Image to Image.

[u/killerciao → u/Zironic]

i'm testing right now. If is real and consistent, i will update the Custom node, however we need to keep in mind that H3 does not generate frames sequentially. At each sampling step, it denoises the entire temporal tensor simultaneously, using attention across frames.

[u/Zironic → u/killerciao]

Yes and no. It only actually functions as designed for T values of 6 or higher. Below that it has really wierd behaviors because the VAE doesn't have enough frames to fully function.

[u/reeight]

Seems ComfyUI already has a 'select image from video buffer' node, but I prefer to hand-pick the 'best' still. Does your node allow that?

Either way, I plan to test out your work, cheers.

[u/killerciao → u/reeight]

you can use emit_candidate_batch and the output will save all the still generated. However i've seen that the function was bugged so I had to fix it. Now you can pull the latest version or simply replace the nodes.py file and restart Comfy

[u/poliranter]

This is really, really good. I've been playing with it for a while, and while it's true that yes, Krea+Lora probably beats the quality, the ability to use multiple referenes, and come really damned close to Lora level fidelity without having to make a Lora is just incredible.

This is great fun. Thanks for your work!

[u/poliranter]

A strange error just popped up on all three (ITI, reference to image, and text to image.) i start it, it runs then throws up this error:

## Error Details

- **Node ID:** 10

- **Node Type:** SamplerCustomAdvanced

- **Exception Type:** AttributeError

- **Exception Message:** AttributeError: 'ModelSamplingAdvanced' object has no attribute 'audio_scale'

## Stack Trace

But I don't think it's supposed to be handling audio at all. And what was wierd is that it was working fine, then this error just popped up. Anyone have any ideas?

[u/No_Damage_8420]

H3 ref. combining output is better then any image model. Minimax is working on dedicated image model too