[K Diffusion] Add k diffusion sampler natively (#1603)

* uP

* uP

examples/community/README.md

@@ -686,7 +686,7 @@ pipe = DiffusionPipeline.from_pretrained("CompVis/stable-diffusion-v1-4", custom
 pipe = pipe.to("cuda")
 
 prompt = "an astronaut riding a horse on mars"
-pipe.set_sampler("sample_heun")
+pipe.set_scheduler("sample_heun")
 generator = torch.Generator(device="cuda").manual_seed(seed)
 image = pipe(prompt, generator=generator, num_inference_steps=20).images[0]
 
@@ -721,7 +721,7 @@ pipe = DiffusionPipeline.from_pretrained("CompVis/stable-diffusion-v1-4", custom
 pipe.scheduler = EulerDiscreteScheduler.from_config(pipe.scheduler.config)
 pipe = pipe.to("cuda")
 
-pipe.set_sampler("sample_euler")
+pipe.set_scheduler("sample_euler")
 generator = torch.Generator(device="cuda").manual_seed(seed)
 image = pipe(prompt, generator=generator, num_inference_steps=50).images[0]
 ```

examples/community/sd_text2img_k_diffusion.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import importlib
+import warnings
 from typing import Callable, List, Optional, Union
 
 import torch
@@ -111,6 +112,10 @@ class StableDiffusionPipeline(DiffusionPipeline):
             self.k_diffusion_model = CompVisDenoiser(model)
 
     def set_sampler(self, scheduler_type: str):
+        warnings.warn("The `set_sampler` method is deprecated, please use `set_scheduler` instead.")
+        return self.set_scheduler(scheduler_type)
+
+    def set_scheduler(self, scheduler_type: str):
         library = importlib.import_module("k_diffusion")
         sampling = getattr(library, "sampling")
         self.sampler = getattr(sampling, scheduler_type)

hi

@@ -0,0 +1 @@
+

setup.py

@@ -91,6 +91,7 @@ _deps = [
     "isort>=5.5.4",
     "jax>=0.2.8,!=0.3.2",
     "jaxlib>=0.1.65",
+    "k-diffusion",
     "librosa",
     "modelcards>=0.1.4",
     "numpy",
@@ -182,6 +183,7 @@ extras["docs"] = deps_list("hf-doc-builder")
 extras["training"] = deps_list("accelerate", "datasets", "tensorboard", "modelcards")
 extras["test"] = deps_list(
     "datasets",
+    "k-diffusion",
     "librosa",
     "parameterized",
     "pytest",

src/diffusers/__init__.py

@@ -5,6 +5,7 @@ from .onnx_utils import OnnxRuntimeModel
 from .utils import (
     is_flax_available,
     is_inflect_available,
+    is_k_diffusion_available,
     is_onnx_available,
     is_scipy_available,
     is_torch_available,
@@ -90,6 +91,11 @@ if is_torch_available() and is_transformers_available():
 else:
     from .utils.dummy_torch_and_transformers_objects import *  # noqa F403
 
+if is_torch_available() and is_transformers_available() and is_k_diffusion_available():
+    from .pipelines import StableDiffusionKDiffusionPipeline
+else:
+    from .utils.dummy_torch_and_transformers_and_k_diffusion_objects import *  # noqa F403
+
 if is_torch_available() and is_transformers_available() and is_onnx_available():
     from .pipelines import (
         OnnxStableDiffusionImg2ImgPipeline,

src/diffusers/dependency_versions_table.py

@@ -15,6 +15,7 @@ deps = {
     "isort": "isort>=5.5.4",
     "jax": "jax>=0.2.8,!=0.3.2",
     "jaxlib": "jaxlib>=0.1.65",
+    "k-diffusion": "k-diffusion",
     "librosa": "librosa",
     "modelcards": "modelcards>=0.1.4",
     "numpy": "numpy",

src/diffusers/pipelines/__init__.py

@@ -1,5 +1,6 @@
 from ..utils import (
     is_flax_available,
+    is_k_diffusion_available,
     is_librosa_available,
     is_onnx_available,
     is_torch_available,
@@ -56,5 +57,8 @@ if is_transformers_available() and is_onnx_available():
         StableDiffusionOnnxPipeline,
     )
 
+if is_torch_available() and is_transformers_available() and is_k_diffusion_available():
+    from .stable_diffusion import StableDiffusionKDiffusionPipeline
+
 if is_transformers_available() and is_flax_available():
     from .stable_diffusion import FlaxStableDiffusionPipeline

src/diffusers/pipelines/stable_diffusion/__init__.py

@@ -9,6 +9,7 @@ from PIL import Image
 from ...utils import (
     BaseOutput,
     is_flax_available,
+    is_k_diffusion_available,
     is_onnx_available,
     is_torch_available,
     is_transformers_available,
@@ -48,6 +49,9 @@ if is_transformers_available() and is_torch_available() and is_transformers_vers
 else:
     from ...utils.dummy_torch_and_transformers_objects import StableDiffusionImageVariationPipeline
 
+if is_transformers_available() and is_torch_available() and is_k_diffusion_available():
+    from .pipeline_stable_diffusion_k_diffusion import StableDiffusionKDiffusionPipeline
+
 if is_transformers_available() and is_onnx_available():
     from .pipeline_onnx_stable_diffusion import OnnxStableDiffusionPipeline, StableDiffusionOnnxPipeline
     from .pipeline_onnx_stable_diffusion_img2img import OnnxStableDiffusionImg2ImgPipeline

src/diffusers/pipelines/stable_diffusion/pipeline_stable_diffusion_k_diffusion.py

@@ -0,0 +1,462 @@
+# Copyright 2022 The HuggingFace Team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import importlib
+from typing import Callable, List, Optional, Union
+
+import torch
+
+from k_diffusion.external import CompVisDenoiser, CompVisVDenoiser
+
+from ... import DiffusionPipeline
+from ...schedulers import LMSDiscreteScheduler
+from ...utils import is_accelerate_available, logging
+from . import StableDiffusionPipelineOutput
+
+
+logger = logging.get_logger(__name__)  # pylint: disable=invalid-name
+
+
+class ModelWrapper:
+    def __init__(self, model, alphas_cumprod):
+        self.model = model
+        self.alphas_cumprod = alphas_cumprod
+
+    def apply_model(self, *args, **kwargs):
+        if len(args) == 3:
+            encoder_hidden_states = args[-1]
+            args = args[:2]
+        if kwargs.get("cond", None) is not None:
+            encoder_hidden_states = kwargs.pop("cond")
+        return self.model(*args, encoder_hidden_states=encoder_hidden_states, **kwargs).sample
+
+
+class StableDiffusionKDiffusionPipeline(DiffusionPipeline):
+    r"""
+    Pipeline for text-to-image generation using Stable Diffusion.
+
+    This model inherits from [`DiffusionPipeline`]. Check the superclass documentation for the generic methods the
+    library implements for all the pipelines (such as downloading or saving, running on a particular device, etc.)
+
+    <Tip warning={true}>
+
+        This is an experimental pipeline and is likely to change in the future.
+
+    </Tip>
+
+    Args:
+        vae ([`AutoencoderKL`]):
+            Variational Auto-Encoder (VAE) Model to encode and decode images to and from latent representations.
+        text_encoder ([`CLIPTextModel`]):
+            Frozen text-encoder. Stable Diffusion uses the text portion of
+            [CLIP](https://huggingface.co/docs/transformers/model_doc/clip#transformers.CLIPTextModel), specifically
+            the [clip-vit-large-patch14](https://huggingface.co/openai/clip-vit-large-patch14) variant.
+        tokenizer (`CLIPTokenizer`):
+            Tokenizer of class
+            [CLIPTokenizer](https://huggingface.co/docs/transformers/v4.21.0/en/model_doc/clip#transformers.CLIPTokenizer).
+        unet ([`UNet2DConditionModel`]): Conditional U-Net architecture to denoise the encoded image latents.
+        scheduler ([`SchedulerMixin`]):
+            A scheduler to be used in combination with `unet` to denoise the encoded image latents. Can be one of
+            [`DDIMScheduler`], [`LMSDiscreteScheduler`], or [`PNDMScheduler`].
+        safety_checker ([`StableDiffusionSafetyChecker`]):
+            Classification module that estimates whether generated images could be considered offensive or harmful.
+            Please, refer to the [model card](https://huggingface.co/runwayml/stable-diffusion-v1-5) for details.
+        feature_extractor ([`CLIPFeatureExtractor`]):
+            Model that extracts features from generated images to be used as inputs for the `safety_checker`.
+    """
+    _optional_components = ["safety_checker", "feature_extractor"]
+
+    def __init__(
+        self,
+        vae,
+        text_encoder,
+        tokenizer,
+        unet,
+        scheduler,
+        safety_checker,
+        feature_extractor,
+        requires_safety_checker: bool = True,
+    ):
+        super().__init__()
+
+        logger.info(
+            f"{self.__class__} is an experimntal pipeline and is likely to change in the future. We recommend to use"
+            " this pipeline for fast experimentation / iteration if needed, but advice to rely on existing pipelines"
+            " as defined in https://huggingface.co/docs/diffusers/api/schedulers#implemented-schedulers for"
+            " production settings."
+        )
+
+        # get correct sigmas from LMS
+        scheduler = LMSDiscreteScheduler.from_config(scheduler.config)
+        self.register_modules(
+            vae=vae,
+            text_encoder=text_encoder,
+            tokenizer=tokenizer,
+            unet=unet,
+            scheduler=scheduler,
+            safety_checker=safety_checker,
+            feature_extractor=feature_extractor,
+        )
+        self.register_to_config(requires_safety_checker=requires_safety_checker)
+        self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1)
+
+        model = ModelWrapper(unet, scheduler.alphas_cumprod)
+        if scheduler.prediction_type == "v_prediction":
+            self.k_diffusion_model = CompVisVDenoiser(model)
+        else:
+            self.k_diffusion_model = CompVisDenoiser(model)
+
+    def set_scheduler(self, scheduler_type: str):
+        library = importlib.import_module("k_diffusion")
+        sampling = getattr(library, "sampling")
+        self.sampler = getattr(sampling, scheduler_type)
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.enable_sequential_cpu_offload
+    def enable_sequential_cpu_offload(self, gpu_id=0):
+        r"""
+        Offloads all models to CPU using accelerate, significantly reducing memory usage. When called, unet,
+        text_encoder, vae and safety checker have their state dicts saved to CPU and then are moved to a
+        `torch.device('meta') and loaded to GPU only when their specific submodule has its `forward` method called.
+        """
+        if is_accelerate_available():
+            from accelerate import cpu_offload
+        else:
+            raise ImportError("Please install accelerate via `pip install accelerate`")
+
+        device = torch.device(f"cuda:{gpu_id}")
+
+        for cpu_offloaded_model in [self.unet, self.text_encoder, self.vae]:
+            if cpu_offloaded_model is not None:
+                cpu_offload(cpu_offloaded_model, device)
+
+        if self.safety_checker is not None:
+            # TODO(Patrick) - there is currently a bug with cpu offload of nn.Parameter in accelerate
+            # fix by only offloading self.safety_checker for now
+            cpu_offload(self.safety_checker.vision_model, device)
+
+    @property
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline._execution_device
+    def _execution_device(self):
+        r"""
+        Returns the device on which the pipeline's models will be executed. After calling
+        `pipeline.enable_sequential_cpu_offload()` the execution device can only be inferred from Accelerate's module
+        hooks.
+        """
+        if self.device != torch.device("meta") or not hasattr(self.unet, "_hf_hook"):
+            return self.device
+        for module in self.unet.modules():
+            if (
+                hasattr(module, "_hf_hook")
+                and hasattr(module._hf_hook, "execution_device")
+                and module._hf_hook.execution_device is not None
+            ):
+                return torch.device(module._hf_hook.execution_device)
+        return self.device
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline._encode_prompt
+    def _encode_prompt(self, prompt, device, num_images_per_prompt, do_classifier_free_guidance, negative_prompt):
+        r"""
+        Encodes the prompt into text encoder hidden states.
+
+        Args:
+            prompt (`str` or `list(int)`):
+                prompt to be encoded
+            device: (`torch.device`):
+                torch device
+            num_images_per_prompt (`int`):
+                number of images that should be generated per prompt
+            do_classifier_free_guidance (`bool`):
+                whether to use classifier free guidance or not
+            negative_prompt (`str` or `List[str]`):
+                The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored
+                if `guidance_scale` is less than `1`).
+        """
+        batch_size = len(prompt) if isinstance(prompt, list) else 1
+
+        text_inputs = self.tokenizer(
+            prompt,
+            padding="max_length",
+            max_length=self.tokenizer.model_max_length,
+            truncation=True,
+            return_tensors="pt",
+        )
+        text_input_ids = text_inputs.input_ids
+        untruncated_ids = self.tokenizer(prompt, padding="max_length", return_tensors="pt").input_ids
+
+        if not torch.equal(text_input_ids, untruncated_ids):
+            removed_text = self.tokenizer.batch_decode(untruncated_ids[:, self.tokenizer.model_max_length - 1 : -1])
+            logger.warning(
+                "The following part of your input was truncated because CLIP can only handle sequences up to"
+                f" {self.tokenizer.model_max_length} tokens: {removed_text}"
+            )
+
+        if hasattr(self.text_encoder.config, "use_attention_mask") and self.text_encoder.config.use_attention_mask:
+            attention_mask = text_inputs.attention_mask.to(device)
+        else:
+            attention_mask = None
+
+        text_embeddings = self.text_encoder(
+            text_input_ids.to(device),
+            attention_mask=attention_mask,
+        )
+        text_embeddings = text_embeddings[0]
+
+        # duplicate text embeddings for each generation per prompt, using mps friendly method
+        bs_embed, seq_len, _ = text_embeddings.shape
+        text_embeddings = text_embeddings.repeat(1, num_images_per_prompt, 1)
+        text_embeddings = text_embeddings.view(bs_embed * num_images_per_prompt, seq_len, -1)
+
+        # get unconditional embeddings for classifier free guidance
+        if do_classifier_free_guidance:
+            uncond_tokens: List[str]
+            if negative_prompt is None:
+                uncond_tokens = [""] * batch_size
+            elif type(prompt) is not type(negative_prompt):
+                raise TypeError(
+                    f"`negative_prompt` should be the same type to `prompt`, but got {type(negative_prompt)} !="
+                    f" {type(prompt)}."
+                )
+            elif isinstance(negative_prompt, str):
+                uncond_tokens = [negative_prompt]
+            elif batch_size != len(negative_prompt):
+                raise ValueError(
+                    f"`negative_prompt`: {negative_prompt} has batch size {len(negative_prompt)}, but `prompt`:"
+                    f" {prompt} has batch size {batch_size}. Please make sure that passed `negative_prompt` matches"
+                    " the batch size of `prompt`."
+                )
+            else:
+                uncond_tokens = negative_prompt
+
+            max_length = text_input_ids.shape[-1]
+            uncond_input = self.tokenizer(
+                uncond_tokens,
+                padding="max_length",
+                max_length=max_length,
+                truncation=True,
+                return_tensors="pt",
+            )
+
+            if hasattr(self.text_encoder.config, "use_attention_mask") and self.text_encoder.config.use_attention_mask:
+                attention_mask = uncond_input.attention_mask.to(device)
+            else:
+                attention_mask = None
+
+            uncond_embeddings = self.text_encoder(
+                uncond_input.input_ids.to(device),
+                attention_mask=attention_mask,
+            )
+            uncond_embeddings = uncond_embeddings[0]
+
+            # duplicate unconditional embeddings for each generation per prompt, using mps friendly method
+            seq_len = uncond_embeddings.shape[1]
+            uncond_embeddings = uncond_embeddings.repeat(1, num_images_per_prompt, 1)
+            uncond_embeddings = uncond_embeddings.view(batch_size * num_images_per_prompt, seq_len, -1)
+
+            # For classifier free guidance, we need to do two forward passes.
+            # Here we concatenate the unconditional and text embeddings into a single batch
+            # to avoid doing two forward passes
+            text_embeddings = torch.cat([uncond_embeddings, text_embeddings])
+
+        return text_embeddings
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.run_safety_checker
+    def run_safety_checker(self, image, device, dtype):
+        if self.safety_checker is not None:
+            safety_checker_input = self.feature_extractor(self.numpy_to_pil(image), return_tensors="pt").to(device)
+            image, has_nsfw_concept = self.safety_checker(
+                images=image, clip_input=safety_checker_input.pixel_values.to(dtype)
+            )
+        else:
+            has_nsfw_concept = None
+        return image, has_nsfw_concept
+
+    # Copied from diffusers.pipelines.stable_diffusion.pipeline_stable_diffusion.StableDiffusionPipeline.decode_latents
+    def decode_latents(self, latents):
+        latents = 1 / 0.18215 * latents
+        image = self.vae.decode(latents).sample
+        image = (image / 2 + 0.5).clamp(0, 1)
+        # we always cast to float32 as this does not cause significant overhead and is compatible with bfloa16
+        image = image.cpu().permute(0, 2, 3, 1).float().numpy()
+        return image
+
+    def check_inputs(self, prompt, height, width, callback_steps):
+        if not isinstance(prompt, str) and not isinstance(prompt, list):
+            raise ValueError(f"`prompt` has to be of type `str` or `list` but is {type(prompt)}")
+
+        if height % 8 != 0 or width % 8 != 0:
+            raise ValueError(f"`height` and `width` have to be divisible by 8 but are {height} and {width}.")
+
+        if (callback_steps is None) or (
+            callback_steps is not None and (not isinstance(callback_steps, int) or callback_steps <= 0)
+        ):
+            raise ValueError(
+                f"`callback_steps` has to be a positive integer but is {callback_steps} of type"
+                f" {type(callback_steps)}."
+            )
+
+    def prepare_latents(self, batch_size, num_channels_latents, height, width, dtype, device, generator, latents=None):
+        shape = (batch_size, num_channels_latents, height // self.vae_scale_factor, width // self.vae_scale_factor)
+        if latents is None:
+            if device.type == "mps":
+                # randn does not work reproducibly on mps
+                latents = torch.randn(shape, generator=generator, device="cpu", dtype=dtype).to(device)
+            else:
+                latents = torch.randn(shape, generator=generator, device=device, dtype=dtype)
+        else:
+            if latents.shape != shape:
+                raise ValueError(f"Unexpected latents shape, got {latents.shape}, expected {shape}")
+            latents = latents.to(device)
+
+        # scale the initial noise by the standard deviation required by the scheduler
+        return latents
+
+    @torch.no_grad()
+    def __call__(
+        self,
+        prompt: Union[str, List[str]],
+        height: int = 512,
+        width: int = 512,
+        num_inference_steps: int = 50,
+        guidance_scale: float = 7.5,
+        negative_prompt: Optional[Union[str, List[str]]] = None,
+        num_images_per_prompt: Optional[int] = 1,
+        eta: float = 0.0,
+        generator: Optional[torch.Generator] = None,
+        latents: Optional[torch.FloatTensor] = None,
+        output_type: Optional[str] = "pil",
+        return_dict: bool = True,
+        callback: Optional[Callable[[int, int, torch.FloatTensor], None]] = None,
+        callback_steps: Optional[int] = 1,
+    ):
+        r"""
+        Function invoked when calling the pipeline for generation.
+
+        Args:
+            prompt (`str` or `List[str]`):
+                The prompt or prompts to guide the image generation.
+            height (`int`, *optional*, defaults to 512):
+                The height in pixels of the generated image.
+            width (`int`, *optional*, defaults to 512):
+                The width in pixels of the generated image.
+            num_inference_steps (`int`, *optional*, defaults to 50):
+                The number of denoising steps. More denoising steps usually lead to a higher quality image at the
+                expense of slower inference.
+            guidance_scale (`float`, *optional*, defaults to 7.5):
+                Guidance scale as defined in [Classifier-Free Diffusion Guidance](https://arxiv.org/abs/2207.12598).
+                `guidance_scale` is defined as `w` of equation 2. of [Imagen
+                Paper](https://arxiv.org/pdf/2205.11487.pdf). Guidance scale is enabled by setting `guidance_scale >
+                1`. Higher guidance scale encourages to generate images that are closely linked to the text `prompt`,
+                usually at the expense of lower image quality.
+            negative_prompt (`str` or `List[str]`, *optional*):
+                The prompt or prompts not to guide the image generation. Ignored when not using guidance (i.e., ignored
+                if `guidance_scale` is less than `1`).
+            num_images_per_prompt (`int`, *optional*, defaults to 1):
+                The number of images to generate per prompt.
+            eta (`float`, *optional*, defaults to 0.0):
+                Corresponds to parameter eta (η) in the DDIM paper: https://arxiv.org/abs/2010.02502. Only applies to
+                [`schedulers.DDIMScheduler`], will be ignored for others.
+            generator (`torch.Generator`, *optional*):
+                A [torch generator](https://pytorch.org/docs/stable/generated/torch.Generator.html) to make generation
+                deterministic.
+            latents (`torch.FloatTensor`, *optional*):
+                Pre-generated noisy latents, sampled from a Gaussian distribution, to be used as inputs for image
+                generation. Can be used to tweak the same generation with different prompts. If not provided, a latents
+                tensor will ge generated by sampling using the supplied random `generator`.
+            output_type (`str`, *optional*, defaults to `"pil"`):
+                The output format of the generate image. Choose between
+                [PIL](https://pillow.readthedocs.io/en/stable/): `PIL.Image.Image` or `np.array`.
+            return_dict (`bool`, *optional*, defaults to `True`):
+                Whether or not to return a [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] instead of a
+                plain tuple.
+            callback (`Callable`, *optional*):
+                A function that will be called every `callback_steps` steps during inference. The function will be
+                called with the following arguments: `callback(step: int, timestep: int, latents: torch.FloatTensor)`.
+            callback_steps (`int`, *optional*, defaults to 1):
+                The frequency at which the `callback` function will be called. If not specified, the callback will be
+                called at every step.
+
+        Returns:
+            [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] or `tuple`:
+            [`~pipelines.stable_diffusion.StableDiffusionPipelineOutput`] if `return_dict` is True, otherwise a `tuple.
+            When returning a tuple, the first element is a list with the generated images, and the second element is a
+            list of `bool`s denoting whether the corresponding generated image likely represents "not-safe-for-work"
+            (nsfw) content, according to the `safety_checker`.
+        """
+
+        # 1. Check inputs. Raise error if not correct
+        self.check_inputs(prompt, height, width, callback_steps)
+
+        # 2. Define call parameters
+        batch_size = 1 if isinstance(prompt, str) else len(prompt)
+        device = self._execution_device
+        # here `guidance_scale` is defined analog to the guidance weight `w` of equation (2)
+        # of the Imagen paper: https://arxiv.org/pdf/2205.11487.pdf . `guidance_scale = 1`
+        # corresponds to doing no classifier free guidance.
+        do_classifier_free_guidance = True
+        if guidance_scale <= 1.0:
+            raise ValueError("has to use guidance_scale")
+
+        # 3. Encode input prompt
+        text_embeddings = self._encode_prompt(
+            prompt, device, num_images_per_prompt, do_classifier_free_guidance, negative_prompt
+        )
+
+        # 4. Prepare timesteps
+        self.scheduler.set_timesteps(num_inference_steps, device=text_embeddings.device)
+        sigmas = self.scheduler.sigmas
+        sigmas = sigmas.to(text_embeddings.dtype)
+
+        # 5. Prepare latent variables
+        num_channels_latents = self.unet.in_channels
+        latents = self.prepare_latents(
+            batch_size * num_images_per_prompt,
+            num_channels_latents,
+            height,
+            width,
+            text_embeddings.dtype,
+            device,
+            generator,
+            latents,
+        )
+        latents = latents * sigmas[0]
+        self.k_diffusion_model.sigmas = self.k_diffusion_model.sigmas.to(latents.device)
+        self.k_diffusion_model.log_sigmas = self.k_diffusion_model.log_sigmas.to(latents.device)
+
+        # 6. Define model function
+        def model_fn(x, t):
+            latent_model_input = torch.cat([x] * 2)
+
+            noise_pred = self.k_diffusion_model(latent_model_input, t, cond=text_embeddings)
+
+            noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)
+            noise_pred = noise_pred_uncond + guidance_scale * (noise_pred_text - noise_pred_uncond)
+            return noise_pred
+
+        # 7. Run k-diffusion solver
+        latents = self.sampler(model_fn, latents, sigmas)
+
+        # 8. Post-processing
+        image = self.decode_latents(latents)
+
+        # 9. Run safety checker
+        image, has_nsfw_concept = self.run_safety_checker(image, device, text_embeddings.dtype)
+
+        # 10. Convert to PIL
+        if output_type == "pil":
+            image = self.numpy_to_pil(image)
+
+        if not return_dict:
+            return (image, has_nsfw_concept)
+
+        return StableDiffusionPipelineOutput(images=image, nsfw_content_detected=has_nsfw_concept)

src/diffusers/utils/__init__.py

@@ -29,6 +29,7 @@ from .import_utils import (
     is_accelerate_available,
     is_flax_available,
     is_inflect_available,
+    is_k_diffusion_available,
     is_librosa_available,
     is_modelcards_available,
     is_onnx_available,

src/diffusers/utils/dummy_torch_and_transformers_and_k_diffusion_objects.py

@@ -0,0 +1,19 @@
+# This file is autogenerated by the command `make fix-copies`, do not edit.
+# flake8: noqa
+
+from ..utils import DummyObject, requires_backends
+
+
+class StableDiffusionKDiffusionPipeline(metaclass=DummyObject):
+    _backends = ["torch", "transformers", "k_diffusion"]
+
+    def __init__(self, *args, **kwargs):
+        requires_backends(self, ["torch", "transformers", "k_diffusion"])
+
+    @classmethod
+    def from_config(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers", "k_diffusion"])
+
+    @classmethod
+    def from_pretrained(cls, *args, **kwargs):
+        requires_backends(cls, ["torch", "transformers", "k_diffusion"])

src/diffusers/utils/import_utils.py

@@ -210,6 +210,13 @@ try:
 except importlib_metadata.PackageNotFoundError:
     _xformers_available = False
 
+_k_diffusion_available = importlib.util.find_spec("k_diffusion") is not None
+try:
+    _k_diffusion_version = importlib_metadata.version("k_diffusion")
+    logger.debug(f"Successfully imported k-diffusion version {_k_diffusion_version}")
+except importlib_metadata.PackageNotFoundError:
+    _k_diffusion_available = False
+
 
 def is_torch_available():
     return _torch_available
@@ -263,6 +270,10 @@ def is_accelerate_available():
     return _accelerate_available
 
 
+def is_k_diffusion_available():
+    return _k_diffusion_available
+
+
 # docstyle-ignore
 FLAX_IMPORT_ERROR = """
 {0} requires the FLAX library but it was not found in your environment. Checkout the instructions on the
@@ -317,6 +328,12 @@ UNIDECODE_IMPORT_ERROR = """
 Unidecode`
 """
 
+# docstyle-ignore
+K_DIFFUSION_IMPORT_ERROR = """
+{0} requires the k-diffusion library but it was not found in your environment. You can install it with pip: `pip
+install k-diffusion`
+"""
+
 
 BACKENDS_MAPPING = OrderedDict(
     [
@@ -329,6 +346,7 @@ BACKENDS_MAPPING = OrderedDict(
         ("transformers", (is_transformers_available, TRANSFORMERS_IMPORT_ERROR)),
         ("unidecode", (is_unidecode_available, UNIDECODE_IMPORT_ERROR)),
         ("librosa", (is_librosa_available, LIBROSA_IMPORT_ERROR)),
+        ("k_diffusion", (is_k_diffusion_available, K_DIFFUSION_IMPORT_ERROR)),
     ]
 )
 

tests/pipelines/stable_diffusion/test_stable_diffusion_k_diffusion.py

@@ -0,0 +1,77 @@
+# coding=utf-8
+# Copyright 2022 HuggingFace Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import gc
+import unittest
+
+import numpy as np
+import torch
+
+from diffusers import StableDiffusionKDiffusionPipeline
+from diffusers.utils import slow, torch_device
+from diffusers.utils.testing_utils import require_torch_gpu
+
+
+torch.backends.cuda.matmul.allow_tf32 = False
+
+
+@slow
+@require_torch_gpu
+class StableDiffusionPipelineIntegrationTests(unittest.TestCase):
+    def tearDown(self):
+        # clean up the VRAM after each test
+        super().tearDown()
+        gc.collect()
+        torch.cuda.empty_cache()
+
+    def test_stable_diffusion_1(self):
+        sd_pipe = StableDiffusionKDiffusionPipeline.from_pretrained("CompVis/stable-diffusion-v1-4")
+        sd_pipe = sd_pipe.to(torch_device)
+        sd_pipe.set_progress_bar_config(disable=None)
+
+        sd_pipe.set_scheduler("sample_euler")
+
+        prompt = "A painting of a squirrel eating a burger"
+        generator = torch.Generator(device=torch_device).manual_seed(0)
+        output = sd_pipe([prompt], generator=generator, guidance_scale=9.0, num_inference_steps=20, output_type="np")
+
+        image = output.images
+
+        image_slice = image[0, -3:, -3:, -1]
+
+        assert image.shape == (1, 512, 512, 3)
+        expected_slice = np.array([0.8887, 0.915, 0.91, 0.894, 0.909, 0.912, 0.919, 0.925, 0.883])
+        assert np.abs(image_slice.flatten() - expected_slice).max() < 1e-2
+
+    def test_stable_diffusion_2(self):
+        sd_pipe = StableDiffusionKDiffusionPipeline.from_pretrained("stabilityai/stable-diffusion-2-1-base")
+        sd_pipe = sd_pipe.to(torch_device)
+        sd_pipe.set_progress_bar_config(disable=None)
+
+        sd_pipe.set_scheduler("sample_euler")
+
+        prompt = "A painting of a squirrel eating a burger"
+        generator = torch.Generator(device=torch_device).manual_seed(0)
+        output = sd_pipe([prompt], generator=generator, guidance_scale=9.0, num_inference_steps=20, output_type="np")
+
+        image = output.images
+
+        image_slice = image[0, -3:, -3:, -1]
+
+        assert image.shape == (1, 512, 512, 3)
+        expected_slice = np.array(
+            [0.826810, 0.81958747, 0.8510199, 0.8376758, 0.83958465, 0.8682068, 0.84370345, 0.85251087, 0.85884345]
+        )
+        assert np.abs(image_slice.flatten() - expected_slice).max() < 1e-2