[ckpt loader] Allow loading the Inpaint and Img2Img pipelines, while loading a ckpt model (#2705)

* [ckpt loader] Allow loading the Inpaint and Img2Img pipelines, while loading a ckpt model

* Address review comment from PR

* PyLint formatting

* Some more pylint fixes, unrelated to our change

* Another pylint fix

* Styling fix

src/diffusers/pipelines/stable_diffusion/convert_from_ckpt.py

@@ -45,6 +45,8 @@ from diffusers import (
     PNDMScheduler,
     PriorTransformer,
     StableDiffusionControlNetPipeline,
+    StableDiffusionImg2ImgPipeline,
+    StableDiffusionInpaintPipeline,
     StableDiffusionPipeline,
     StableUnCLIPImg2ImgPipeline,
     StableUnCLIPPipeline,
@@ -979,6 +981,7 @@ def download_from_original_stable_diffusion_ckpt(
     image_size: int = 512,
     prediction_type: str = None,
     model_type: str = None,
+    is_img2img: bool = False,
     extract_ema: bool = False,
     scheduler_type: str = "pndm",
     num_in_channels: Optional[int] = None,
@@ -1018,6 +1021,8 @@ def download_from_original_stable_diffusion_ckpt(
         model_type (`str`, *optional*, defaults to `None`):
             The pipeline type. `None` to automatically infer, or one of `["FrozenOpenCLIPEmbedder",
             "FrozenCLIPEmbedder", "PaintByExample"]`.
+        is_img2img (`bool`, *optional*, defaults to `False`):
+            Whether the model should be loaded as an img2img pipeline.
         extract_ema (`bool`, *optional*, defaults to `False`): Only relevant for
             checkpoints that have both EMA and non-EMA weights. Whether to extract the EMA weights or not. Defaults to
             `False`. Pass `True` to extract the EMA weights. EMA weights usually yield higher quality images for
@@ -1192,6 +1197,34 @@ def download_from_original_stable_diffusion_ckpt(
                     feature_extractor=None,
                     requires_safety_checker=False,
                 )
+            else:
+                if (
+                    hasattr(original_config, "model")
+                    and hasattr(original_config.model, "target")
+                    and "LatentInpaintDiffusion" in original_config.model.target
+                ):
+                    pipe = StableDiffusionInpaintPipeline(
+                        vae=vae,
+                        text_encoder=text_model,
+                        tokenizer=tokenizer,
+                        unet=unet,
+                        scheduler=scheduler,
+                        safety_checker=None,
+                        feature_extractor=None,
+                        requires_safety_checker=False,
+                    )
+                else:
+                    if is_img2img:
+                        pipe = StableDiffusionImg2ImgPipeline(
+                            vae=vae,
+                            text_encoder=text_model,
+                            tokenizer=tokenizer,
+                            unet=unet,
+                            scheduler=scheduler,
+                            safety_checker=None,
+                            feature_extractor=None,
+                            requires_safety_checker=False,
+                        )
                     else:
                         pipe = StableDiffusionPipeline(
                             vae=vae,
@@ -1292,6 +1325,32 @@ def download_from_original_stable_diffusion_ckpt(
                 safety_checker=safety_checker,
                 feature_extractor=feature_extractor,
             )
+        else:
+            if (
+                hasattr(original_config, "model")
+                and hasattr(original_config.model, "target")
+                and "LatentInpaintDiffusion" in original_config.model.target
+            ):
+                pipe = StableDiffusionInpaintPipeline(
+                    vae=vae,
+                    text_encoder=text_model,
+                    tokenizer=tokenizer,
+                    unet=unet,
+                    scheduler=scheduler,
+                    safety_checker=safety_checker,
+                    feature_extractor=feature_extractor,
+                )
+            else:
+                if is_img2img:
+                    pipe = StableDiffusionImg2ImgPipeline(
+                        vae=vae,
+                        text_encoder=text_model,
+                        tokenizer=tokenizer,
+                        unet=unet,
+                        scheduler=scheduler,
+                        safety_checker=safety_checker,
+                        feature_extractor=feature_extractor,
+                    )
                 else:
                     pipe = StableDiffusionPipeline(
                         vae=vae,