Flux img2img remote encode

Author: hlky

src/diffusers/pipelines/flux/pipeline_flux_img2img.py

@@ -225,7 +225,10 @@ def __init__(
         self.vae_scale_factor = 2 ** (len(self.vae.config.block_out_channels) - 1) if getattr(self, "vae", None) else 8
         # Flux latents are turned into 2x2 patches and packed. This means the latent width and height has to be divisible
         # by the patch size. So the vae scale factor is multiplied by the patch size to account for this
-        self.image_processor = VaeImageProcessor(vae_scale_factor=self.vae_scale_factor * 2)
+        self.latent_channels = self.vae.config.latent_channels if getattr(self, "vae", None) else 16
+        self.image_processor = VaeImageProcessor(
+            vae_scale_factor=self.vae_scale_factor * 2, vae_latent_channels=self.latent_channels
+        )
         self.tokenizer_max_length = (
             self.tokenizer.model_max_length if hasattr(self, "tokenizer") and self.tokenizer is not None else 77
         )
@@ -634,7 +637,8 @@ def prepare_latents(
             return latents.to(device=device, dtype=dtype), latent_image_ids
 
         image = image.to(device=device, dtype=dtype)
-        image_latents = self._encode_vae_image(image=image, generator=generator)
+        if image.shape[1] != self.latent_channels:
+            image_latents = self._encode_vae_image(image=image, generator=generator)
         if batch_size > image_latents.shape[0] and batch_size % image_latents.shape[0] == 0:
             # expand init_latents for batch_size
             additional_image_per_prompt = batch_size // image_latents.shape[0]