Flux.1-Krea-Merged-Dev (Flux.1-Dev + Flux.1-Krea-Dev)

The Flux.1-Krea-Merged-Dev repository contains merged parameters combining two advanced image generation models: black-forest-labs/FLUX.1-dev and black-forest-labs/FLUX.1-Krea-dev. This merged model integrates the capabilities of the rectified flow transformer FLUX.1-dev, known for competitive prompt following and high-quality outputs, with FLUX.1-Krea-dev, a guidance distilled model emphasizing aesthetics and photorealism. The result is a unified model that balances quality, aesthetic control, and efficiency for text-to-image generation tasks. The repository includes instructions for loading, merging, and using the fused parameters via the Diffusers library, enabling users to generate images from text prompts through the FluxPipeline with enhanced performance and visual quality. This merge facilitates leveraging strengths from both base models in a single, accessible implementation for research and creative workflows.

FLUX.1-dev (28 steps)	FLUX.1-Krea-dev (28 steps)	Flux.1-Krea-Merged-Dev (28 steps)

prompt : a tiny astronaut hatching from an egg on the moon

---

FLUX.1-dev (28 steps)	FLUX.1-Krea-dev (28 steps)	Flux.1-Krea-Merged-Dev (28 steps)

prompt : cute anime illustration of a colorful sushi platter featuring nigiri, maki rolls, sashimi, and wasabi on a wooden tray with decorative two chopsticks.

---

Sub-Memory-efficient merging code (Flux.1-Dev + Flux.1-Krea-Dev)

Installing Required Packages

%%capture
!pip install git+https://github.com/huggingface/transformers.git
!pip install git+https://github.com/huggingface/diffusers.git
!pip install git+https://github.com/huggingface/peft.git
!pip install git+https://github.com/huggingface/accelerate.git
!pip install safetensors huggingface_hub hf_xet

hf-login

from huggingface_hub import notebook_login, HfApi
notebook_login()

merge.py

from diffusers import FluxTransformer2DModel
from huggingface_hub import snapshot_download
from accelerate import init_empty_weights
from diffusers.models.model_loading_utils import load_model_dict_into_meta
import safetensors.torch
import glob
import torch

# Initialize model with empty weights
with init_empty_weights():
    config = FluxTransformer2DModel.load_config("black-forest-labs/FLUX.1-dev", subfolder="transformer")
    model = FluxTransformer2DModel.from_config(config)

# Download checkpoints
dev_ckpt = snapshot_download(repo_id="black-forest-labs/FLUX.1-dev", allow_patterns="transformer/*")
krea_ckpt = snapshot_download(repo_id="black-forest-labs/FLUX.1-Krea-dev", allow_patterns="transformer/*")

# Get sorted shard paths
dev_shards = sorted(glob.glob(f"{dev_ckpt}/transformer/*.safetensors"))
krea_shards = sorted(glob.glob(f"{krea_ckpt}/transformer/*.safetensors"))

# Initialize dictionaries for merged and guidance weights
merged_state_dict = {}
guidance_state_dict = {}

# Merge shards
for dev_shard, krea_shard in zip(dev_shards, krea_shards):
    state_dict_dev = safetensors.torch.load_file(dev_shard)
    state_dict_krea = safetensors.torch.load_file(krea_shard)

    # Process keys from dev model
    for k in list(state_dict_dev.keys()):
        if "guidance" in k:
            # Keep guidance weights from dev model
            guidance_state_dict[k] = state_dict_dev.pop(k)
        else:
            # Average non-guidance weights if key exists in krea
            if k in state_dict_krea:
                merged_state_dict[k] = (state_dict_dev.pop(k) + state_dict_krea.pop(k)) / 2
            else:
                raise ValueError(f"Key {k} missing in krea shard.")

    # Check for residual keys in krea (e.g., extra guidance keys)
    for k in list(state_dict_krea.keys()):
        if "guidance" in k:
            # Skip extra guidance keys in krea
            state_dict_krea.pop(k)
        else:
            raise ValueError(f"Unexpected non-guidance key in krea shard: {k}")

    # Verify no unexpected residue
    if len(state_dict_dev) > 0:
        raise ValueError(f"Residue in dev shard: {list(state_dict_dev.keys())}")
    if len(state_dict_krea) > 0:
        raise ValueError(f"Residue in krea shard: {list(state_dict_krea.keys())}")

# Combine merged and guidance state dictionaries
merged_state_dict.update(guidance_state_dict)

# Load merged state dictionary into model
load_model_dict_into_meta(model, merged_state_dict)

# Convert to bfloat16 and save
model.to(torch.bfloat16).save_pretrained("merged/transformer")

api = HfApi()
repo_id = "prithivMLmods/Flux.1-Krea-Merged-Dev"

api.upload_folder(
    folder_path="merged/",
    path_in_repo=".",
    repo_id=repo_id,
    repo_type="model",
    revision="main"
)

---

Inference Code🧨

from diffusers import FluxPipeline
import torch

pipeline = FluxPipeline.from_pretrained(
    "prithivMLmods/Flux.1-Krea-Merged-Dev", torch_dtype=torch.bfloat16
).to("cuda")
image = pipeline(
    prompt="a tiny astronaut hatching from an egg on the moon",
    guidance_scale=3.5,
    num_inference_steps=28,
    height=1024,
    width=1024,
    max_sequence_length=512,
    generator=torch.manual_seed(0),
).images[0]
image.save("img0.png")

---

Quick Start with Gradio and Transformers🤗

COMPARATOR : FLUX.1-Dev(Realism) and FLUX.1-Krea-Merged-Dev (Flux.1-Dev + Flux.1-Krea-Dev)

Installing Required Packages

%%capture
!pip install git+https://github.com/huggingface/transformers.git
!pip install git+https://github.com/huggingface/diffusers.git
!pip install git+https://github.com/huggingface/peft.git
!pip install git+https://github.com/huggingface/accelerate.git
!pip install safetensors huggingface_hub hf_xet

hf-login

from huggingface_hub import notebook_login, HfApi
notebook_login()

app.py

import spaces
import gradio as gr
import torch
from PIL import Image
from diffusers import DiffusionPipeline, AutoencoderTiny, AutoencoderKL
import random
import uuid
from typing import Tuple, Union, List, Optional, Any, Dict
import numpy as np
import time
import zipfile
from transformers import CLIPTextModel, CLIPTokenizer, T5EncoderModel, T5TokenizerFast

# Description for the app
DESCRIPTION = """## flux comparator hpc/."""

# Helper functions
def save_image(img):
    unique_name = str(uuid.uuid4()) + ".png"
    img.save(unique_name)
    return unique_name

def randomize_seed_fn(seed: int, randomize_seed: bool) -> int:
    if randomize_seed:
        seed = random.randint(0, MAX_SEED)
    return seed

MAX_SEED = np.iinfo(np.int32).max
MAX_IMAGE_SIZE = 2048

# Load pipelines for both models
# Flux.1-dev-realism
base_model_dev = "black-forest-labs/FLUX.1-dev"
pipe_dev = DiffusionPipeline.from_pretrained(base_model_dev, torch_dtype=torch.bfloat16)
lora_repo = "strangerzonehf/Flux-Super-Realism-LoRA"
trigger_word = "Super Realism"
pipe_dev.load_lora_weights(lora_repo)
pipe_dev.to("cuda")

# Flux.1-krea
dtype = torch.bfloat16
device = "cuda" if torch.cuda.is_available() else "cpu"
taef1 = AutoencoderTiny.from_pretrained("madebyollin/taef1", torch_dtype=dtype).to(device)
good_vae = AutoencoderKL.from_pretrained("prithivMLmods/Flux.1-Krea-Merged-Dev", subfolder="vae", torch_dtype=dtype).to(device)
pipe_krea = DiffusionPipeline.from_pretrained("prithivMLmods/Flux.1-Krea-Merged-Dev", torch_dtype=dtype, vae=taef1).to(device)

# Define the flux_pipe_call_that_returns_an_iterable_of_images for flux.1-krea
@torch.inference_mode()
def flux_pipe_call_that_returns_an_iterable_of_images(
    self,
    prompt: Union[str, List[str]] = None,
    prompt_2: Optional[Union[str, List[str]]] = None,
    height: Optional[int] = None,
    width: Optional[int] = None,
    num_inference_steps: int = 28,
    timesteps: List[int] = None,
    guidance_scale: float = 3.5,
    num_images_per_prompt: Optional[int] = 1,
    generator: Optional[Union[torch.Generator, List[torch.Generator]]] = None,
    latents: Optional[torch.FloatTensor] = None,
    prompt_embeds: Optional[torch.FloatTensor] = None,
    pooled_prompt_embeds: Optional[torch.FloatTensor] = None,
    output_type: Optional[str] = "pil",
    return_dict: bool = True,
    joint_attention_kwargs: Optional[Dict[str, Any]] = None,
    max_sequence_length: int = 512,
    good_vae: Optional[Any] = None,
):
    height = height or self.default_sample_size * self.vae_scale_factor
    width = width or self.default_sample_size * self.vae_scale_factor

    self.check_inputs(
        prompt,
        prompt_2,
        height,
        width,
        prompt_embeds=prompt_embeds,
        pooled_prompt_embeds=pooled_prompt_embeds,
        max_sequence_length=max_sequence_length,
    )

    self._guidance_scale = guidance_scale
    self._joint_attention_kwargs = joint_attention_kwargs
    self._interrupt = False

    batch_size = 1 if isinstance(prompt, str) else len(prompt)
    device = self._execution_device

    lora_scale = joint_attention_kwargs.get("scale", None) if joint_attention_kwargs is not None else None
    prompt_embeds, pooled_prompt_embeds, text_ids = self.encode_prompt(
        prompt=prompt,
        prompt_2=prompt_2,
        prompt_embeds=prompt_embeds,
        pooled_prompt_embeds=pooled_prompt_embeds,
        device=device,
        num_images_per_prompt=num_images_per_prompt,
        max_sequence_length=max_sequence_length,
        lora_scale=lora_scale,
    )

    num_channels_latents = self.transformer.config.in_channels // 4
    latents, latent_image_ids = self.prepare_latents(
        batch_size * num_images_per_prompt,
        num_channels_latents,
        height,
        width,
        prompt_embeds.dtype,
        device,
        generator,
        latents,
    )

    sigmas = np.linspace(1.0, 1 / num_inference_steps, num_inference_steps)
    image_seq_len = latents.shape[1]
    mu = calculate_shift(
        image_seq_len,
        self.scheduler.config.base_image_seq_len,
        self.scheduler.config.max_image_seq_len,
        self.scheduler.config.base_shift,
        self.scheduler.config.max_shift,
    )
    timesteps, num_inference_steps = retrieve_timesteps(
        self.scheduler,
        num_inference_steps,
        device,
        timesteps,
        sigmas,
        mu=mu,
    )
    self._num_timesteps = len(timesteps)

    guidance = torch.full([1], guidance_scale, device=device, dtype=torch.float32).expand(latents.shape[0]) if self.transformer.config.guidance_embeds else None

    for i, t in enumerate(timesteps):
        if self.interrupt:
            continue

        timestep = t.expand(latents.shape[0]).to(latents.dtype)

        noise_pred = self.transformer(
            hidden_states=latents,
            timestep=timestep / 1000,
            guidance=guidance,
            pooled_projections=pooled_prompt_embeds,
            encoder_hidden_states=prompt_embeds,
            txt_ids=text_ids,
            img_ids=latent_image_ids,
            joint_attention_kwargs=self.joint_attention_kwargs,
            return_dict=False,
        )[0]

        latents_for_image = self._unpack_latents(latents, height, width, self.vae_scale_factor)
        latents_for_image = (latents_for_image / self.vae.config.scaling_factor) + self.vae.config.shift_factor
        image = self.vae.decode(latents_for_image, return_dict=False)[0]
        yield self.image_processor.postprocess(image, output_type=output_type)[0]
        
        latents = self.scheduler.step(noise_pred, t, latents, return_dict=False)[0]
        torch.cuda.empty_cache()

    latents = self._unpack_latents(latents, height, width, self.vae_scale_factor)
    latents = (latents / good_vae.config.scaling_factor) + good_vae.config.shift_factor
    image = good_vae.decode(latents, return_dict=False)[0]
    self.maybe_free_model_hooks()
    torch.cuda.empty_cache()
    yield self.image_processor.postprocess(image, output_type=output_type)[0]

pipe_krea.flux_pipe_call_that_returns_an_iterable_of_images = flux_pipe_call_that_returns_an_iterable_of_images.__get__(pipe_krea)

# Helper functions for flux.1-krea
def calculate_shift(
    image_seq_len,
    base_seq_len: int = 256,
    max_seq_len: int = 4096,
    base_shift: float = 0.5,
    max_shift: float = 1.16,
):
    m = (max_shift - base_shift) / (max_seq_len - base_seq_len)
    b = base_shift - m * base_seq_len
    mu = image_seq_len * m + b
    return mu

def retrieve_timesteps(
    scheduler,
    num_inference_steps: Optional[int] = None,
    device: Optional[Union[str, torch.device]] = None,
    timesteps: Optional[List[int]] = None,
    sigmas: Optional[List[float]] = None,
    **kwargs,
):
    if timesteps is not None and sigmas is not None:
        raise ValueError("Only one of `timesteps` or `sigmas` can be passed.")
    if timesteps is not None:
        scheduler.set_timesteps(timesteps=timesteps, device=device, **kwargs)
        timesteps = scheduler.timesteps
        num_inference_steps = len(timesteps)
    elif sigmas is not None:
        scheduler.set_timesteps(sigmas=sigmas, device=device, **kwargs)
        timesteps = scheduler.timesteps
        num_inference_steps = len(timesteps)
    else:
        scheduler.set_timesteps(num_inference_steps, device=device, **kwargs)
        timesteps = scheduler.timesteps
    return timesteps, num_inference_steps

# Styles for flux.1-dev-realism
style_list = [
    {"name": "3840 x 2160", "prompt": "hyper-realistic 8K image of {prompt}. ultra-detailed, lifelike, high-resolution, sharp, vibrant colors, photorealistic", "negative_prompt": ""},
    {"name": "2560 x 1440", "prompt": "hyper-realistic 4K image of {prompt}. ultra-detailed, lifelike, high-resolution, sharp, vibrant colors, photorealistic", "negative_prompt": ""},
    {"name": "HD+", "prompt": "hyper-realistic 2K image of {prompt}. ultra-detailed, lifelike, high-resolution, sharp, vibrant colors, photorealistic", "negative_prompt": ""},
    {"name": "Style Zero", "prompt": "{prompt}", "negative_prompt": ""},
]

styles = {k["name"]: (k["prompt"], k["negative_prompt"]) for k in style_list}
DEFAULT_STYLE_NAME = "3840 x 2160"
STYLE_NAMES = list(styles.keys())

def apply_style(style_name: str, positive: str) -> Tuple[str, str]:
    p, n = styles.get(style_name, styles[DEFAULT_STYLE_NAME])
    return p.replace("{prompt}", positive), n

# Generation function for flux.1-dev-realism
@spaces.GPU
def generate_dev(
    prompt: str,
    negative_prompt: str = "",
    use_negative_prompt: bool = False,
    seed: int = 0,
    width: int = 1024,
    height: int = 1024,
    guidance_scale: float = 3,
    randomize_seed: bool = False,
    style_name: str = DEFAULT_STYLE_NAME,
    num_inference_steps: int = 30,
    num_images: int = 1,
    zip_images: bool = False,
    progress=gr.Progress(track_tqdm=True),
):
    positive_prompt, style_negative_prompt = apply_style(style_name, prompt)
    
    if use_negative_prompt:
        final_negative_prompt = style_negative_prompt + " " + negative_prompt
    else:
        final_negative_prompt = style_negative_prompt
    
    final_negative_prompt = final_negative_prompt.strip()
    
    if trigger_word:
        positive_prompt = f"{trigger_word} {positive_prompt}"
    
    seed = int(randomize_seed_fn(seed, randomize_seed))
    generator = torch.Generator(device="cuda").manual_seed(seed)
    
    start_time = time.time()
    
    images = pipe_dev(
        prompt=positive_prompt,
        negative_prompt=final_negative_prompt if final_negative_prompt else None,
        width=width,
        height=height,
        guidance_scale=guidance_scale,
        num_inference_steps=num_inference_steps,
        num_images_per_prompt=num_images,
        generator=generator,
        output_type="pil",
    ).images
    
    end_time = time.time()
    duration = end_time - start_time
    
    image_paths = [save_image(img) for img in images]
    
    zip_path = None
    if zip_images:
        zip_name = str(uuid.uuid4()) + ".zip"
        with zipfile.ZipFile(zip_name, 'w') as zipf:
            for i, img_path in enumerate(image_paths):
                zipf.write(img_path, arcname=f"Img_{i}.png")
        zip_path = zip_name
    
    return image_paths, seed, f"{duration:.2f}", zip_path

# Generation function for flux.1-krea
@spaces.GPU
def generate_krea(
    prompt: str,
    seed: int = 0,
    width: int = 1024,
    height: int = 1024,
    guidance_scale: float = 4.5,
    randomize_seed: bool = False,
    num_inference_steps: int = 28,
    num_images: int = 1,
    zip_images: bool = False,
    progress=gr.Progress(track_tqdm=True),
):
    if randomize_seed:
        seed = random.randint(0, MAX_SEED)
    generator = torch.Generator().manual_seed(seed)
    
    start_time = time.time()
    
    images = []
    for _ in range(num_images):
        final_img = list(pipe_krea.flux_pipe_call_that_returns_an_iterable_of_images(
            prompt=prompt,
            guidance_scale=guidance_scale,
            num_inference_steps=num_inference_steps,
            width=width,
            height=height,
            generator=generator,
            output_type="pil",
            good_vae=good_vae,
        ))[-1]  # Take the final image only
        images.append(final_img)
    
    end_time = time.time()
    duration = end_time - start_time
    
    image_paths = [save_image(img) for img in images]
    
    zip_path = None
    if zip_images:
        zip_name = str(uuid.uuid4()) + ".zip"
        with zipfile.ZipFile(zip_name, 'w') as zipf:
            for i, img_path in enumerate(image_paths):
                zipf.write(img_path, arcname=f"Img_{i}.png")
        zip_path = zip_name
    
    return image_paths, seed, f"{duration:.2f}", zip_path

# Main generation function to handle model choice
@spaces.GPU
def generate(
    model_choice: str,
    prompt: str,
    negative_prompt: str = "",
    use_negative_prompt: bool = False,
    seed: int = 0,
    width: int = 1024,
    height: int = 1024,
    guidance_scale: float = 3,
    randomize_seed: bool = False,
    style_name: str = DEFAULT_STYLE_NAME,
    num_inference_steps: int = 30,
    num_images: int = 1,
    zip_images: bool = False,
    progress=gr.Progress(track_tqdm=True),
):
    if model_choice == "flux.1-dev-realism":
        return generate_dev(
            prompt=prompt,
            negative_prompt=negative_prompt,
            use_negative_prompt=use_negative_prompt,
            seed=seed,
            width=width,
            height=height,
            guidance_scale=guidance_scale,
            randomize_seed=randomize_seed,
            style_name=style_name,
            num_inference_steps=num_inference_steps,
            num_images=num_images,
            zip_images=zip_images,
            progress=progress,
        )
    elif model_choice == "flux.1-krea-merged-dev":
        return generate_krea(
            prompt=prompt,
            seed=seed,
            width=width,
            height=height,
            guidance_scale=guidance_scale,
            randomize_seed=randomize_seed,
            num_inference_steps=num_inference_steps,
            num_images=num_images,
            zip_images=zip_images,
            progress=progress,
        )
    else:
        raise ValueError("Invalid model choice")

# Examples (tailored for flux.1-dev-realism)
examples = [
    "An attractive young woman with blue eyes lying face down on the bed, in the style of animated gifs, light white and light amber, jagged edges, the snapshot aesthetic, timeless beauty, goosepunk, sunrays shine upon it --no freckles --chaos 65 --ar 1:2 --profile yruxpc2 --stylize 750 --v 6.1",
    "Headshot of handsome young man, wearing dark gray sweater with buttons and big shawl collar, brown hair and short beard, serious look on his face, black background, soft studio lighting, portrait photography --ar 85:128 --v 6.0 --style",
    "Purple Dreamy, a medium-angle shot of a young woman with long brown hair, wearing a pair of eye-level glasses, stands in front of a backdrop of purple and white lights.",
    "High-resolution photograph, woman, UHD, photorealistic, shot on a Sony A7III --chaos 20 --ar 1:2 --style raw --stylize 250"
]

css = '''
.gradio-container {
    max-width: 590px !important;
    margin: 0 auto !important;
}
h1 {
    text-align: center;
}
footer {
    visibility: hidden;
}
'''

# Gradio interface
with gr.Blocks(css=css, theme="bethecloud/storj_theme") as demo:
    gr.Markdown(DESCRIPTION)
    with gr.Row():
        prompt = gr.Text(
            label="Prompt",
            show_label=False,
            max_lines=1,
            placeholder="Enter your prompt",
            container=False,
        )
        run_button = gr.Button("Run", scale=0, variant="primary")
    result = gr.Gallery(label="Result", columns=1, show_label=False, preview=True)
    
    with gr.Row():
    # Model choice radio button above additional options
        model_choice = gr.Radio(
            choices=["flux.1-krea-merged-dev", "flux.1-dev-realism"],
            label="Select Model",
            value="flux.1-krea-merged-dev"
        )
    
    with gr.Accordion("Additional Options", open=False):
        style_selection = gr.Dropdown(
            label="Quality Style (for flux.1-dev-realism only)",
            choices=STYLE_NAMES,
            value=DEFAULT_STYLE_NAME,
            interactive=True,
        )
        use_negative_prompt = gr.Checkbox(label="Use negative prompt (for flux.1-dev-realism only)", value=False)
        negative_prompt = gr.Text(
            label="Negative prompt",
            max_lines=1,
            placeholder="Enter a negative prompt",
            visible=False,
        )
        seed = gr.Slider(
            label="Seed",
            minimum=0,
            maximum=MAX_SEED,
            step=1,
            value=0,
        )
        randomize_seed = gr.Checkbox(label="Randomize seed", value=True)
        with gr.Row():
            width = gr.Slider(
                label="Width",
                minimum=512,
                maximum=2048,
                step=64,
                value=1024,
            )
            height = gr.Slider(
                label="Height",
                minimum=512,
                maximum=2048,
                step=64,
                value=1024,
            )
        guidance_scale = gr.Slider(
            label="Guidance Scale",
            minimum=0.1,
            maximum=20.0,
            step=0.1,
            value=3.5,
        )
        num_inference_steps = gr.Slider(
            label="Number of inference steps",
            minimum=1,
            maximum=40,
            step=1,
            value=28,
        )
        num_images = gr.Slider(
            label="Number of images",
            minimum=1,
            maximum=5,
            step=1,
            value=1,
        )
        zip_images = gr.Checkbox(label="Zip generated images", value=False)
        
        gr.Markdown("### Output Information")
        seed_display = gr.Textbox(label="Seed used", interactive=False)
        generation_time = gr.Textbox(label="Generation time (seconds)", interactive=False)
        zip_file = gr.File(label="Download ZIP")

    gr.Examples(
        examples=examples,
        inputs=prompt,
        outputs=[result, seed_display, generation_time, zip_file],
        fn=generate,
        cache_examples=False,
    )

    use_negative_prompt.change(
        fn=lambda x: gr.update(visible=x),
        inputs=use_negative_prompt,
        outputs=negative_prompt,
        api_name=False,
    )

    gr.on(
        triggers=[
            prompt.submit,
            run_button.click,
        ],
        fn=generate,
        inputs=[
            model_choice,
            prompt,
            negative_prompt,
            use_negative_prompt,
            seed,
            width,
            height,
            guidance_scale,
            randomize_seed,
            style_selection,
            num_inference_steps,
            num_images,
            zip_images,
        ],
        outputs=[result, seed_display, generation_time, zip_file],
        api_name="run",
    )

if __name__ == "__main__":
    demo.queue(max_size=30).launch(mcp_server=True, ssr_mode=False, show_error=True)

Recommended runtime type

@hardware-accelerator : H200

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For more information, visit the documentation.

Flux is a suite of state-of-the-art text-to-image generation models based on diffusion transformers, developed by Black Forest Labs. The models are designed for high-quality generative image tasks, including text-to-image, inpainting, outpainting, and advanced structure or depth-controlled workflows. Flux is available through the Hugging Face diffusers library.

For detailed guides, examples, and API refer to:

• Main Flux Pipeline Documentation
• Flux Transformer Model Documentation