@@ -0,0 +1,91 @@
+# coding=utf-8
+# Copyright 2023 The HuggingFace Inc. team.
+#
+# 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.
+""" Conversion script for stable diffusion checkpoints which _only_ contain a contrlnet. """
+
+import argparse
+
+from diffusers.pipelines.stable_diffusion.convert_from_ckpt import download_controlnet_from_original_ckpt
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument(
+        "--checkpoint_path", default=None, type=str, required=True, help="Path to the checkpoint to convert."
+    )
+    parser.add_argument(
+        "--original_config_file",
+        type=str,
+        required=True,
+        help="The YAML config file corresponding to the original architecture.",
+    )
+    parser.add_argument(
+        "--num_in_channels",
+        default=None,
+        type=int,
+        help="The number of input channels. If `None` number of input channels will be automatically inferred.",
+    )
+    parser.add_argument(
+        "--image_size",
+        default=512,
+        type=int,
+        help=(
+            "The image size that the model was trained on. Use 512 for Stable Diffusion v1.X and Stable Siffusion v2"
+            " Base. Use 768 for Stable Diffusion v2."
+        ),
+    )
+    parser.add_argument(
+        "--extract_ema",
+        action="store_true",
+        help=(
+            "Only relevant for checkpoints that have both EMA and non-EMA weights. Whether to extract the EMA weights"
+            " or not. Defaults to `False`. Add `--extract_ema` to extract the EMA weights. EMA weights usually yield"
+            " higher quality images for inference. Non-EMA weights are usually better to continue fine-tuning."
+        ),
+    )
+    parser.add_argument(
+        "--upcast_attention",
+        action="store_true",
+        help=(
+            "Whether the attention computation should always be upcasted. This is necessary when running stable"
+            " diffusion 2.1."
+        ),
+    )
+    parser.add_argument(
+        "--from_safetensors",
+        action="store_true",
+        help="If `--checkpoint_path` is in `safetensors` format, load checkpoint with safetensors instead of PyTorch.",
+    )
+    parser.add_argument(
+        "--to_safetensors",
+        action="store_true",
+        help="Whether to store pipeline in safetensors format or not.",
+    )
+    parser.add_argument("--dump_path", default=None, type=str, required=True, help="Path to the output model.")
+    parser.add_argument("--device", type=str, help="Device to use (e.g. cpu, cuda:0, cuda:1, etc.)")
+    args = parser.parse_args()
+
+    controlnet = download_controlnet_from_original_ckpt(
+        checkpoint_path=args.checkpoint_path,
+        original_config_file=args.original_config_file,
+        image_size=args.image_size,
+        extract_ema=args.extract_ema,
+        num_in_channels=args.num_in_channels,
+        upcast_attention=args.upcast_attention,
+        from_safetensors=args.from_safetensors,
+        device=args.device,
+    )
+
+    controlnet.save_pretrained(args.dump_path, safe_serialization=args.to_safetensors)
@@ -954,6 +954,25 @@ def stable_unclip_image_noising_components(
     return image_normalizer, image_noising_scheduler
 
 
+def convert_controlnet_checkpoint(
+    checkpoint, original_config, checkpoint_path, image_size, upcast_attention, extract_ema
+):
+    ctrlnet_config = create_unet_diffusers_config(original_config, image_size=image_size, controlnet=True)
+    ctrlnet_config["upcast_attention"] = upcast_attention
+
+    ctrlnet_config.pop("sample_size")
+
+    controlnet_model = ControlNetModel(**ctrlnet_config)
+
+    converted_ctrl_checkpoint = convert_ldm_unet_checkpoint(
+        checkpoint, ctrlnet_config, path=checkpoint_path, extract_ema=extract_ema, controlnet=True
+    )
+
+    controlnet_model.load_state_dict(converted_ctrl_checkpoint)
+
+    return controlnet_model
+
+
 def download_from_original_stable_diffusion_ckpt(
     checkpoint_path: str,
     original_config_file: str = None,
@@ -1042,7 +1061,9 @@ def download_from_original_stable_diffusion_ckpt(
         print("global_step key not found in model")
         global_step = None
 
-    if "state_dict" in checkpoint:
+    # NOTE: this while loop isn't great but this controlnet checkpoint has one additional
+    # "state_dict" key https://huggingface.co/thibaud/controlnet-canny-sd21
+    while "state_dict" in checkpoint:
         checkpoint = checkpoint["state_dict"]
 
     if original_config_file is None:
@@ -1084,6 +1105,14 @@ def download_from_original_stable_diffusion_ckpt(
         if image_size is None:
             image_size = 512
 
+    if controlnet is None:
+        controlnet = "control_stage_config" in original_config.model.params
+
+    if controlnet:
+        controlnet_model = convert_controlnet_checkpoint(
+            checkpoint, original_config, checkpoint_path, image_size, upcast_attention, extract_ema
+        )
+
     num_train_timesteps = original_config.model.params.timesteps
     beta_start = original_config.model.params.linear_start
     beta_end = original_config.model.params.linear_end
@@ -1143,27 +1172,34 @@ def download_from_original_stable_diffusion_ckpt(
         model_type = original_config.model.params.cond_stage_config.target.split(".")[-1]
         logger.debug(f"no `model_type` given, `model_type` inferred as: {model_type}")
 
-    if controlnet is None:
-        controlnet = "control_stage_config" in original_config.model.params
-
-    if controlnet and model_type != "FrozenCLIPEmbedder":
-        raise ValueError("`controlnet`=True only supports `model_type`='FrozenCLIPEmbedder'")
-
     if model_type == "FrozenOpenCLIPEmbedder":
         text_model = convert_open_clip_checkpoint(checkpoint)
         tokenizer = CLIPTokenizer.from_pretrained("stabilityai/stable-diffusion-2", subfolder="tokenizer")
 
         if stable_unclip is None:
-            pipe = StableDiffusionPipeline(
-                vae=vae,
-                text_encoder=text_model,
-                tokenizer=tokenizer,
-                unet=unet,
-                scheduler=scheduler,
-                safety_checker=None,
-                feature_extractor=None,
-                requires_safety_checker=False,
-            )
+            if controlnet:
+                pipe = StableDiffusionControlNetPipeline(
+                    vae=vae,
+                    text_encoder=text_model,
+                    tokenizer=tokenizer,
+                    unet=unet,
+                    scheduler=scheduler,
+                    controlnet=controlnet_model,
+                    safety_checker=None,
+                    feature_extractor=None,
+                    requires_safety_checker=False,
+                )
+            else:
+                pipe = StableDiffusionPipeline(
+                    vae=vae,
+                    text_encoder=text_model,
+                    tokenizer=tokenizer,
+                    unet=unet,
+                    scheduler=scheduler,
+                    safety_checker=None,
+                    feature_extractor=None,
+                    requires_safety_checker=False,
+                )
         else:
             image_normalizer, image_noising_scheduler = stable_unclip_image_noising_components(
                 original_config, clip_stats_path=clip_stats_path, device=device
@@ -1238,19 +1274,6 @@ def download_from_original_stable_diffusion_ckpt(
         feature_extractor = AutoFeatureExtractor.from_pretrained("CompVis/stable-diffusion-safety-checker")
 
         if controlnet:
-            # Convert the ControlNetModel model.
-            ctrlnet_config = create_unet_diffusers_config(original_config, image_size=image_size, controlnet=True)
-            ctrlnet_config["upcast_attention"] = upcast_attention
-
-            ctrlnet_config.pop("sample_size")
-
-            controlnet_model = ControlNetModel(**ctrlnet_config)
-
-            converted_ctrl_checkpoint = convert_ldm_unet_checkpoint(
-                checkpoint, ctrlnet_config, path=checkpoint_path, extract_ema=extract_ema, controlnet=True
-            )
-            controlnet_model.load_state_dict(converted_ctrl_checkpoint)
-
             pipe = StableDiffusionControlNetPipeline(
                 vae=vae,
                 text_encoder=text_model,
@@ -1278,3 +1301,55 @@ def download_from_original_stable_diffusion_ckpt(
         pipe = LDMTextToImagePipeline(vqvae=vae, bert=text_model, tokenizer=tokenizer, unet=unet, scheduler=scheduler)
 
     return pipe
+
+
+def download_controlnet_from_original_ckpt(
+    checkpoint_path: str,
+    original_config_file: str,
+    image_size: int = 512,
+    extract_ema: bool = False,
+    num_in_channels: Optional[int] = None,
+    upcast_attention: Optional[bool] = None,
+    device: str = None,
+    from_safetensors: bool = False,
+) -> StableDiffusionPipeline:
+    if not is_omegaconf_available():
+        raise ValueError(BACKENDS_MAPPING["omegaconf"][1])
+
+    from omegaconf import OmegaConf
+
+    if from_safetensors:
+        if not is_safetensors_available():
+            raise ValueError(BACKENDS_MAPPING["safetensors"][1])
+
+        from safetensors import safe_open
+
+        checkpoint = {}
+        with safe_open(checkpoint_path, framework="pt", device="cpu") as f:
+            for key in f.keys():
+                checkpoint[key] = f.get_tensor(key)
+    else:
+        if device is None:
+            device = "cuda" if torch.cuda.is_available() else "cpu"
+            checkpoint = torch.load(checkpoint_path, map_location=device)
+        else:
+            checkpoint = torch.load(checkpoint_path, map_location=device)
+
+    # NOTE: this while loop isn't great but this controlnet checkpoint has one additional
+    # "state_dict" key https://huggingface.co/thibaud/controlnet-canny-sd21
+    while "state_dict" in checkpoint:
+        checkpoint = checkpoint["state_dict"]
+
+    original_config = OmegaConf.load(original_config_file)
+
+    if num_in_channels is not None:
+        original_config["model"]["params"]["unet_config"]["params"]["in_channels"] = num_in_channels
+
+    if "control_stage_config" not in original_config.model.params:
+        raise ValueError("`control_stage_config` not present in original config")
+
+    controlnet_model = convert_controlnet_checkpoint(
+        checkpoint, original_config, checkpoint_path, image_size, upcast_attention, extract_ema
+    )
+
+    return controlnet_model