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# QwenImage

<div class="flex flex-wrap space-x-1">
  <img alt="LoRA" src="https://img.shields.io/badge/LoRA-d8b4fe?style=flat"/>
</div>

Qwen-Image from the Qwen team is an image generation foundation model in the Qwen series that achieves significant advances in complex text rendering and precise image editing. Experiments show strong general capabilities in both image generation and editing, with exceptional performance in text rendering, especially for Chinese.

Qwen-Image comes in the following variants:

| model type | model id |
|:----------:|:--------:|
| Qwen-Image | [`Qwen/Qwen-Image`](https://huggingface.co/Qwen/Qwen-Image) |
| Qwen-Image-Edit | [`Qwen/Qwen-Image-Edit`](https://huggingface.co/Qwen/Qwen-Image-Edit) |
| Qwen-Image-Edit Plus | [Qwen/Qwen-Image-Edit-2509](https://huggingface.co/Qwen/Qwen-Image-Edit-2509) |

> [!TIP]
> [Caching](../../optimization/cache) may also speed up inference by storing and reusing intermediate outputs.

## LoRA for faster inference

Use a LoRA from `lightx2v/Qwen-Image-Lightning` to speed up inference by reducing the
number of steps. Refer to the code snippet below:

<details>
<summary>Code</summary>

```py
from diffusers import DiffusionPipeline, FlowMatchEulerDiscreteScheduler
import torch 
import math

ckpt_id = "Qwen/Qwen-Image"

# From
# https://github.com/ModelTC/Qwen-Image-Lightning/blob/342260e8f5468d2f24d084ce04f55e101007118b/generate_with_diffusers.py#L82C9-L97C10
scheduler_config = {
    "base_image_seq_len": 256,
    "base_shift": math.log(3),  # We use shift=3 in distillation
    "invert_sigmas": False,
    "max_image_seq_len": 8192,
    "max_shift": math.log(3),  # We use shift=3 in distillation
    "num_train_timesteps": 1000,
    "shift": 1.0,
    "shift_terminal": None,  # set shift_terminal to None
    "stochastic_sampling": False,
    "time_shift_type": "exponential",
    "use_beta_sigmas": False,
    "use_dynamic_shifting": True,
    "use_exponential_sigmas": False,
    "use_karras_sigmas": False,
}
scheduler = FlowMatchEulerDiscreteScheduler.from_config(scheduler_config)
pipe = DiffusionPipeline.from_pretrained(
    ckpt_id, scheduler=scheduler, torch_dtype=torch.bfloat16
).to("cuda")
pipe.load_lora_weights(
    "lightx2v/Qwen-Image-Lightning", weight_name="Qwen-Image-Lightning-8steps-V1.0.safetensors"
)

prompt = "a tiny astronaut hatching from an egg on the moon, Ultra HD, 4K, cinematic composition."
negative_prompt = " "
image = pipe(
    prompt=prompt,
    negative_prompt=negative_prompt,
    width=1024,
    height=1024,
    num_inference_steps=8,
    true_cfg_scale=1.0,
    generator=torch.manual_seed(0),
).images[0]
image.save("qwen_fewsteps.png")
```

</details>

> [!TIP]
> The `guidance_scale` parameter in the pipeline is there to support future guidance-distilled models when they come up. Note that passing `guidance_scale` to the pipeline is ineffective. To enable classifier-free guidance, please pass `true_cfg_scale` and `negative_prompt` (even an empty negative prompt like " ") should enable classifier-free guidance computations.

## Multi-image reference with QwenImageEditPlusPipeline

With [`QwenImageEditPlusPipeline`], one can provide multiple images as input reference.

```py
import torch
from PIL import Image
from diffusers import QwenImageEditPlusPipeline
from diffusers.utils import load_image

pipe = QwenImageEditPlusPipeline.from_pretrained(
    "Qwen/Qwen-Image-Edit-2509", torch_dtype=torch.bfloat16
).to("cuda")

image_1 = load_image("https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/grumpy.jpg")
image_2 = load_image("https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/peng.png")
image = pipe(
    image=[image_1, image_2],
    prompt='''put the penguin and the cat at a game show called "Qwen Edit Plus Games"''',
    num_inference_steps=50
).images[0]
```

## Performance

### torch.compile

Using `torch.compile` on the transformer provides ~2.4x speedup (A100 80GB: 4.70s → 1.93s):

```python
import torch
from diffusers import QwenImagePipeline

pipe = QwenImagePipeline.from_pretrained("Qwen/Qwen-Image", torch_dtype=torch.bfloat16).to("cuda")
pipe.transformer = torch.compile(pipe.transformer)

# First call triggers compilation (~7s overhead)
# Subsequent calls run at ~2.4x faster
image = pipe("a cat", num_inference_steps=50).images[0]
```

### Batched Inference with Variable-Length Prompts

When using classifier-free guidance (CFG) with prompts of different lengths, the pipeline properly handles padding through attention masking. This ensures padding tokens do not influence the generated output.

```python
# CFG with different prompt lengths works correctly
image = pipe(
    prompt="A cat",
    negative_prompt="blurry, low quality, distorted",
    true_cfg_scale=3.5,
    num_inference_steps=50,
).images[0]
```

For detailed benchmark scripts and results, see [this gist](https://gist.github.com/cdutr/bea337e4680268168550292d7819dc2f).

## QwenImagePipeline

[[autodoc]] QwenImagePipeline
  - all
  - __call__

## QwenImageImg2ImgPipeline

[[autodoc]] QwenImageImg2ImgPipeline
  - all
  - __call__

## QwenImageInpaintPipeline

[[autodoc]] QwenImageInpaintPipeline
  - all
  - __call__

## QwenImageEditPipeline

[[autodoc]] QwenImageEditPipeline
  - all
  - __call__

## QwenImageEditInpaintPipeline

[[autodoc]] QwenImageEditInpaintPipeline
  - all
  - __call__

## QwenImageControlNetPipeline

[[autodoc]] QwenImageControlNetPipeline
  - all
  - __call__

## QwenImageEditPlusPipeline

[[autodoc]] QwenImageEditPlusPipeline
  - all
  - __call__

## QwenImagePipelineOutput

[[autodoc]] pipelines.qwenimage.pipeline_output.QwenImagePipelineOutput