WanI2V encode_image (#11164)

* WanI2V encode_image

src/diffusers/pipelines/wan/pipeline_wan_i2v.py

@@ -220,8 +220,13 @@ class WanImageToVideoPipeline(DiffusionPipeline, WanLoraLoaderMixin):
 
         return prompt_embeds
 
-    def encode_image(self, image: PipelineImageInput):
-        image = self.image_processor(images=image, return_tensors="pt").to(self.device)
+    def encode_image(
+        self,
+        image: PipelineImageInput,
+        device: Optional[torch.device] = None,
+    ):
+        device = device or self._execution_device
+        image = self.image_processor(images=image, return_tensors="pt").to(device)
         image_embeds = self.image_encoder(**image, output_hidden_states=True)
         return image_embeds.hidden_states[-2]
 
@@ -587,7 +592,7 @@ class WanImageToVideoPipeline(DiffusionPipeline, WanLoraLoaderMixin):
         if negative_prompt_embeds is not None:
             negative_prompt_embeds = negative_prompt_embeds.to(transformer_dtype)
 
-        image_embeds = self.encode_image(image)
+        image_embeds = self.encode_image(image, device)
         image_embeds = image_embeds.repeat(batch_size, 1, 1)
         image_embeds = image_embeds.to(transformer_dtype)