add torch.Generator to MultiUpscaler.upscale + make MultiUpscaler.diffuse_targets "stateless"

Author: Laurent

src/refiners/foundationals/latent_diffusion/stable_diffusion_1/multi_upscaler.py

@@ -8,7 +8,7 @@
 from torch import Tensor
 from typing_extensions import TypeVar
 
-from refiners.fluxion.utils import image_to_tensor, load_from_safetensors, manual_seed, no_grad
+from refiners.fluxion.utils import image_to_tensor, load_from_safetensors, no_grad
 from refiners.foundationals.clip.concepts import ConceptExtender
 from refiners.foundationals.latent_diffusion.lora import SDLoraManager
 from refiners.foundationals.latent_diffusion.multi_diffusion import DiffusionTarget, MultiDiffusion, Size
@@ -217,13 +217,12 @@ def compute_upscaler_targets(
 
     def diffuse_targets(
         self,
+        noise: torch.Tensor,
         targets: Sequence[T],
         image: Image.Image,
-        latent_size: Size,
         first_step: int,
         autoencoder_tile_length: int,
     ) -> Image.Image:
-        noise = torch.randn(size=(1, 4, *latent_size), device=self.device, dtype=self.dtype)
         with self.sd.lda.tiled_inference(image, (autoencoder_tile_length, autoencoder_tile_length)):
             latents = self.sd.lda.tiled_image_to_latents(image)
             x = self.sd.solver.add_noise(x=latents, noise=noise, step=first_step)
@@ -249,7 +248,7 @@ def upscale(
         solver_type: type[Solver] = DPMSolver,
         num_inference_steps: int = 18,
         autoencoder_tile_length: int = 1024,
-        seed: int = 37,
+        generator: torch.Generator | None = None,
     ) -> Image.Image:
         """
         Upscale an image using the multi upscaler.
@@ -280,10 +279,8 @@ def upscale(
                 between quality and speed.
             autoencoder_tile_length: The length of the autoencoder tiles. It shouldn't affect the end result, but
                 lowering it can reduce GPU memory usage (but increase computation time).
-            seed: The seed to use for the random number generator.
+            generator: The random number generator to use for sampling noise.
         """
-        manual_seed(seed)
-
         # update controlnet scale
         self.controlnet.scale = controlnet_scale
         self.controlnet.scale_decay = controlnet_scale_decay
@@ -323,11 +320,19 @@ def upscale(
             clip_text_embedding=clip_text_embedding,
         )
 
+        # initialize the noise
+        noise = torch.randn(
+            size=(1, 4, *latent_size),
+            device=self.device,
+            dtype=self.dtype,
+            generator=generator,
+        )
+
         # diffuse the tiles
         return self.diffuse_targets(
+            noise=noise,
             targets=targets,
             image=image,
-            latent_size=latent_size,
             first_step=first_step,
             autoencoder_tile_length=autoencoder_tile_length,
         )

tests/e2e/test_diffusion.py

@@ -2669,7 +2669,9 @@ def test_multi_upscaler(
     clarity_example: Image.Image,
     expected_multi_upscaler: Image.Image,
 ) -> None:
-    predicted_image = multi_upscaler.upscale(clarity_example)
+    generator = torch.Generator(device=multi_upscaler.device)
+    generator.manual_seed(37)
+    predicted_image = multi_upscaler.upscale(clarity_example, generator=generator)
     ensure_similar_images(predicted_image, expected_multi_upscaler, min_psnr=35, min_ssim=0.99)