Add support for IPAdapterFull (#5911)

* Add support for IPAdapterFull
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

---------
Co-authored-by: YiYi Xu <yixu310@gmail.com>
Co-authored-by: Patrick von Platen <patrick.v.platen@gmail.com>

docs/source/en/using-diffusers/loading_adapters.md

@@ -485,6 +485,69 @@ image.save("sdxl_t2i.png")
   </div>
 </div>
 
+You can use the IP-Adapter face model to apply specific faces to your images.  It is an effective way to maintain consistent characters in your image generations.
+Weights are loaded with the same method used for the other IP-Adapters.  
+
+```python
+# Load ip-adapter-full-face_sd15.bin
+pipeline.load_ip_adapter("h94/IP-Adapter", subfolder="models", weight_name="ip-adapter-full-face_sd15.bin")
+```
+
+<Tip>
+
+It is recommended to use `DDIMScheduler` and `EulerDiscreteScheduler` for face model. 
+
+
+</Tip>
+
+```python
+import torch
+from diffusers import StableDiffusionPipeline, DDIMScheduler
+from diffusers.utils import load_image
+
+noise_scheduler = DDIMScheduler(
+    num_train_timesteps=1000,
+    beta_start=0.00085,
+    beta_end=0.012,
+    beta_schedule="scaled_linear",
+    clip_sample=False,
+    set_alpha_to_one=False,
+    steps_offset=1
+)
+
+pipeline = StableDiffusionPipeline.from_pretrained(
+    "runwayml/stable-diffusion-v1-5",
+    torch_dtype=torch.float16,
+    scheduler=noise_scheduler,
+).to("cuda")
+
+pipeline.load_ip_adapter("h94/IP-Adapter", subfolder="models", weight_name="ip-adapter-full-face_sd15.bin")
+
+pipeline.set_ip_adapter_scale(0.7)
+
+image = load_image("https://huggingface.co/datasets/YiYiXu/testing-images/resolve/main/ai_face2.png")
+
+generator = torch.Generator(device="cpu").manual_seed(33)
+
+image = pipeline(
+    prompt="A photo of a girl wearing a black dress, holding red roses in hand, upper body, behind is the Eiffel Tower",
+    ip_adapter_image=image,
+    negative_prompt="monochrome, lowres, bad anatomy, worst quality, low quality", 
+    num_inference_steps=50, num_images_per_prompt=1, width=512, height=704,
+    generator=generator,
+).images[0]
+```
+
+<div class="flex flex-row gap-4">
+  <div class="flex-1">
+    <img class="rounded-xl" src="https://huggingface.co/datasets/YiYiXu/testing-images/resolve/main/ai_face2.png"/>
+    <figcaption class="mt-2 text-center text-sm text-gray-500">input image</figcaption>
+  </div>
+  <div class="flex-1">
+    <img class="rounded-xl" src="https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/diffusers/ipadapter_full_face_output.png"/>
+    <figcaption class="mt-2 text-center text-sm text-gray-500">output image</figcaption>
+  </div>
+</div>
 
 ### LCM-Lora
 

src/diffusers/loaders/unet.py

@@ -22,7 +22,7 @@ import torch.nn.functional as F
 from huggingface_hub.utils import validate_hf_hub_args
 from torch import nn
 
-from ..models.embeddings import ImageProjection, Resampler
+from ..models.embeddings import ImageProjection, MLPProjection, Resampler
 from ..models.modeling_utils import _LOW_CPU_MEM_USAGE_DEFAULT, load_model_dict_into_meta
 from ..utils import (
     USE_PEFT_BACKEND,
@@ -675,6 +675,9 @@ class UNet2DConditionLoadersMixin:
         if "proj.weight" in state_dict["image_proj"]:
             # IP-Adapter
             num_image_text_embeds = 4
+        elif "proj.3.weight" in state_dict["image_proj"]:
+            # IP-Adapter Full Face
+            num_image_text_embeds = 257  # 256 CLIP tokens + 1 CLS token
         else:
             # IP-Adapter Plus
             num_image_text_embeds = state_dict["image_proj"]["latents"].shape[1]
@@ -744,8 +747,32 @@ class UNet2DConditionLoadersMixin:
                     "norm.bias": state_dict["image_proj"]["norm.bias"],
                 }
             )
+            image_projection.load_state_dict(image_proj_state_dict)
+            del image_proj_state_dict
 
+        elif "proj.3.weight" in state_dict["image_proj"]:
+            clip_embeddings_dim = state_dict["image_proj"]["proj.0.weight"].shape[0]
+            cross_attention_dim = state_dict["image_proj"]["proj.3.weight"].shape[0]
+
+            image_projection = MLPProjection(
+                cross_attention_dim=cross_attention_dim, image_embed_dim=clip_embeddings_dim
+            )
+            image_projection.to(dtype=self.dtype, device=self.device)
+
+            # load image projection layer weights
+            image_proj_state_dict = {}
+            image_proj_state_dict.update(
+                {
+                    "ff.net.0.proj.weight": state_dict["image_proj"]["proj.0.weight"],
+                    "ff.net.0.proj.bias": state_dict["image_proj"]["proj.0.bias"],
+                    "ff.net.2.weight": state_dict["image_proj"]["proj.2.weight"],
+                    "ff.net.2.bias": state_dict["image_proj"]["proj.2.bias"],
+                    "norm.weight": state_dict["image_proj"]["proj.3.weight"],
+                    "norm.bias": state_dict["image_proj"]["proj.3.bias"],
+                }
+            )
             image_projection.load_state_dict(image_proj_state_dict)
+            del image_proj_state_dict
 
         else:
             # IP-Adapter Plus

src/diffusers/models/embeddings.py

@@ -461,6 +461,18 @@ class ImageProjection(nn.Module):
         return image_embeds
 
 
+class MLPProjection(nn.Module):
+    def __init__(self, image_embed_dim=1024, cross_attention_dim=1024):
+        super().__init__()
+        from .attention import FeedForward
+
+        self.ff = FeedForward(image_embed_dim, cross_attention_dim, mult=1, activation_fn="gelu")
+        self.norm = nn.LayerNorm(cross_attention_dim)
+
+    def forward(self, image_embeds: torch.FloatTensor):
+        return self.norm(self.ff(image_embeds))
+
+
 class CombinedTimestepLabelEmbeddings(nn.Module):
     def __init__(self, num_classes, embedding_dim, class_dropout_prob=0.1):
         super().__init__()

tests/pipelines/ip_adapters/test_ip_adapter_stable_diffusion.py

@@ -182,6 +182,25 @@ class IPAdapterSDIntegrationTests(IPAdapterNightlyTestsMixin):
 
         assert np.allclose(image_slice, expected_slice, atol=1e-4, rtol=1e-4)
 
+    def test_text_to_image_full_face(self):
+        image_encoder = self.get_image_encoder(repo_id="h94/IP-Adapter", subfolder="models/image_encoder")
+        pipeline = StableDiffusionPipeline.from_pretrained(
+            "runwayml/stable-diffusion-v1-5", image_encoder=image_encoder, safety_checker=None, torch_dtype=self.dtype
+        )
+        pipeline.to(torch_device)
+        pipeline.load_ip_adapter("h94/IP-Adapter", subfolder="models", weight_name="ip-adapter-full-face_sd15.bin")
+        pipeline.set_ip_adapter_scale(0.7)
+
+        inputs = self.get_dummy_inputs()
+        images = pipeline(**inputs).images
+        image_slice = images[0, :3, :3, -1].flatten()
+
+        expected_slice = np.array(
+            [0.1706543, 0.1303711, 0.12573242, 0.21777344, 0.14550781, 0.14038086, 0.40820312, 0.41455078, 0.42529297]
+        )
+
+        assert np.allclose(image_slice, expected_slice, atol=1e-4, rtol=1e-4)
+
 
 @slow
 @require_torch_gpu