Add converter method for ip adapters (#6150)

* Add converter method for ip adapters

* Move converter method

* Update to image proj converter

---------
Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

src/diffusers/loaders/unet.py

@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import os
-from collections import OrderedDict, defaultdict
+from collections import defaultdict
 from contextlib import nullcontext
 from typing import Callable, Dict, List, Optional, Union
 
@@ -664,6 +664,80 @@ class UNet2DConditionLoadersMixin:
             if hasattr(self, "peft_config"):
                 self.peft_config.pop(adapter_name, None)
 
+    def _convert_ip_adapter_image_proj_to_diffusers(self, state_dict):
+        updated_state_dict = {}
+        image_projection = None
+
+        if "proj.weight" in state_dict:
+            # IP-Adapter
+            num_image_text_embeds = 4
+            clip_embeddings_dim = state_dict["proj.weight"].shape[-1]
+            cross_attention_dim = state_dict["proj.weight"].shape[0] // 4
+
+            image_projection = ImageProjection(
+                cross_attention_dim=cross_attention_dim,
+                image_embed_dim=clip_embeddings_dim,
+                num_image_text_embeds=num_image_text_embeds,
+            )
+
+            for key, value in state_dict.items():
+                diffusers_name = key.replace("proj", "image_embeds")
+                updated_state_dict[diffusers_name] = value
+
+        elif "proj.3.weight" in state_dict:
+            # IP-Adapter Full
+            clip_embeddings_dim = state_dict["proj.0.weight"].shape[0]
+            cross_attention_dim = state_dict["proj.3.weight"].shape[0]
+
+            image_projection = MLPProjection(
+                cross_attention_dim=cross_attention_dim, image_embed_dim=clip_embeddings_dim
+            )
+
+            for key, value in state_dict.items():
+                diffusers_name = key.replace("proj.0", "ff.net.0.proj")
+                diffusers_name = diffusers_name.replace("proj.2", "ff.net.2")
+                diffusers_name = diffusers_name.replace("proj.3", "norm")
+                updated_state_dict[diffusers_name] = value
+
+        else:
+            # IP-Adapter Plus
+            num_image_text_embeds = state_dict["latents"].shape[1]
+            embed_dims = state_dict["proj_in.weight"].shape[1]
+            output_dims = state_dict["proj_out.weight"].shape[0]
+            hidden_dims = state_dict["latents"].shape[2]
+            heads = state_dict["layers.0.0.to_q.weight"].shape[0] // 64
+
+            image_projection = Resampler(
+                embed_dims=embed_dims,
+                output_dims=output_dims,
+                hidden_dims=hidden_dims,
+                heads=heads,
+                num_queries=num_image_text_embeds,
+            )
+
+            for key, value in state_dict.items():
+                diffusers_name = key.replace("0.to", "2.to")
+                diffusers_name = diffusers_name.replace("1.0.weight", "3.0.weight")
+                diffusers_name = diffusers_name.replace("1.0.bias", "3.0.bias")
+                diffusers_name = diffusers_name.replace("1.1.weight", "3.1.net.0.proj.weight")
+                diffusers_name = diffusers_name.replace("1.3.weight", "3.1.net.2.weight")
+
+                if "norm1" in diffusers_name:
+                    updated_state_dict[diffusers_name.replace("0.norm1", "0")] = value
+                elif "norm2" in diffusers_name:
+                    updated_state_dict[diffusers_name.replace("0.norm2", "1")] = value
+                elif "to_kv" in diffusers_name:
+                    v_chunk = value.chunk(2, dim=0)
+                    updated_state_dict[diffusers_name.replace("to_kv", "to_k")] = v_chunk[0]
+                    updated_state_dict[diffusers_name.replace("to_kv", "to_v")] = v_chunk[1]
+                elif "to_out" in diffusers_name:
+                    updated_state_dict[diffusers_name.replace("to_out", "to_out.0")] = value
+                else:
+                    updated_state_dict[diffusers_name] = value
+
+        image_projection.load_state_dict(updated_state_dict)
+        return image_projection
+
     def _load_ip_adapter_weights(self, state_dict):
         from ..models.attention_processor import (
             AttnProcessor,
@@ -724,103 +798,8 @@ class UNet2DConditionLoadersMixin:
 
         self.set_attn_processor(attn_procs)
 
-        # create image projection layers.
-        if "proj.weight" in state_dict["image_proj"]:
-            # IP-Adapter
-            clip_embeddings_dim = state_dict["image_proj"]["proj.weight"].shape[-1]
-            cross_attention_dim = state_dict["image_proj"]["proj.weight"].shape[0] // 4
-
-            image_projection = ImageProjection(
-                cross_attention_dim=cross_attention_dim,
-                image_embed_dim=clip_embeddings_dim,
-                num_image_text_embeds=num_image_text_embeds,
-            )
-            image_projection.to(dtype=self.dtype, device=self.device)
-
-            # load image projection layer weights
-            image_proj_state_dict = {}
-            image_proj_state_dict.update(
-                {
-                    "image_embeds.weight": state_dict["image_proj"]["proj.weight"],
-                    "image_embeds.bias": state_dict["image_proj"]["proj.bias"],
-                    "norm.weight": state_dict["image_proj"]["norm.weight"],
-                    "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
-            embed_dims = state_dict["image_proj"]["proj_in.weight"].shape[1]
-            output_dims = state_dict["image_proj"]["proj_out.weight"].shape[0]
-            hidden_dims = state_dict["image_proj"]["latents"].shape[2]
-            heads = state_dict["image_proj"]["layers.0.0.to_q.weight"].shape[0] // 64
-
-            image_projection = Resampler(
-                embed_dims=embed_dims,
-                output_dims=output_dims,
-                hidden_dims=hidden_dims,
-                heads=heads,
-                num_queries=num_image_text_embeds,
-            )
-
-            image_proj_state_dict = state_dict["image_proj"]
-
-            new_sd = OrderedDict()
-            for k, v in image_proj_state_dict.items():
-                if "0.to" in k:
-                    k = k.replace("0.to", "2.to")
-                elif "1.0.weight" in k:
-                    k = k.replace("1.0.weight", "3.0.weight")
-                elif "1.0.bias" in k:
-                    k = k.replace("1.0.bias", "3.0.bias")
-                elif "1.1.weight" in k:
-                    k = k.replace("1.1.weight", "3.1.net.0.proj.weight")
-                elif "1.3.weight" in k:
-                    k = k.replace("1.3.weight", "3.1.net.2.weight")
-
-                if "norm1" in k:
-                    new_sd[k.replace("0.norm1", "0")] = v
-                elif "norm2" in k:
-                    new_sd[k.replace("0.norm2", "1")] = v
-                elif "to_kv" in k:
-                    v_chunk = v.chunk(2, dim=0)
-                    new_sd[k.replace("to_kv", "to_k")] = v_chunk[0]
-                    new_sd[k.replace("to_kv", "to_v")] = v_chunk[1]
-                elif "to_out" in k:
-                    new_sd[k.replace("to_out", "to_out.0")] = v
-                else:
-                    new_sd[k] = v
-
-            image_projection.load_state_dict(new_sd)
-            del image_proj_state_dict
+        # convert IP-Adapter Image Projection layers to diffusers
+        image_projection = self._convert_ip_adapter_image_proj_to_diffusers(state_dict["image_proj"])
 
         self.encoder_hid_proj = image_projection.to(device=self.device, dtype=self.dtype)
         self.config.encoder_hid_dim_type = "ip_image_proj"
-
-    delete_adapter_layers