Add tiling to SpandrelImageToImageInvocation

invokeai/app/invocations/spandrel_image_to_image.py

@@ -1,4 +1,7 @@
+import numpy as np
 import torch
+from PIL import Image
+from tqdm import tqdm
 
 from invokeai.app.invocations.baseinvocation import BaseInvocation, invocation
 from invokeai.app.invocations.fields import (
@@ -13,9 +16,11 @@
 from invokeai.app.invocations.primitives import ImageOutput
 from invokeai.app.services.shared.invocation_context import InvocationContext
 from invokeai.backend.spandrel_image_to_image_model import SpandrelImageToImageModel
+from invokeai.backend.tiles.tiles import calc_tiles_min_overlap
+from invokeai.backend.tiles.utils import TBLR, Tile
 
 
-@invocation("spandrel_image_to_image", title="Image-to-Image", tags=["upscale"], category="upscale", version="1.0.0")
+@invocation("spandrel_image_to_image", title="Image-to-Image", tags=["upscale"], category="upscale", version="1.1.0")
 class SpandrelImageToImageInvocation(BaseInvocation, WithMetadata, WithBoard):
     """Run any spandrel image-to-image model (https://github.com/chaiNNer-org/spandrel)."""
 
@@ -25,25 +30,110 @@ class SpandrelImageToImageInvocation(BaseInvocation, WithMetadata, WithBoard):
         description=FieldDescriptions.spandrel_image_to_image_model,
         ui_type=UIType.SpandrelImageToImageModel,
     )
+    tile_size: int = InputField(
+        default=512, description="The tile size for tiled image-to-image. Set to 0 to disable tiling."
+    )
+
+    def _scale_tile(self, tile: Tile, scale: int) -> Tile:
+        return Tile(
+            coords=TBLR(
+                top=tile.coords.top * scale,
+                bottom=tile.coords.bottom * scale,
+                left=tile.coords.left * scale,
+                right=tile.coords.right * scale,
+            ),
+            overlap=TBLR(
+                top=tile.overlap.top * scale,
+                bottom=tile.overlap.bottom * scale,
+                left=tile.overlap.left * scale,
+                right=tile.overlap.right * scale,
+            ),
+        )
 
     @torch.inference_mode()
     def invoke(self, context: InvocationContext) -> ImageOutput:
-        image = context.images.get_pil(self.image.image_name)
+        # Images are converted to RGB, because most models don't support an alpha channel. In the future, we may want to
+        # revisit this.
+        image = context.images.get_pil(self.image.image_name, mode="RGB")
+
+        # Compute the image tiles.
+        if self.tile_size > 0:
+            min_overlap = 20
+            tiles = calc_tiles_min_overlap(
+                image_height=image.height,
+                image_width=image.width,
+                tile_height=self.tile_size,
+                tile_width=self.tile_size,
+                min_overlap=min_overlap,
+            )
+        else:
+            # No tiling. Generate a single tile that covers the entire image.
+            min_overlap = 0
+            tiles = [
+                Tile(
+                    coords=TBLR(top=0, bottom=image.height, left=0, right=image.width),
+                    overlap=TBLR(top=0, bottom=0, left=0, right=0),
+                )
+            ]
+
+        # Sort tiles first by left x coordinate, then by top y coordinate. During tile processing, we want to iterate
+        # over tiles left-to-right, top-to-bottom.
+        tiles = sorted(tiles, key=lambda x: x.coords.left)
+        tiles = sorted(tiles, key=lambda x: x.coords.top)
+
+        # Prepare input image for inference.
+        image_tensor = SpandrelImageToImageModel.pil_to_tensor(image)
 
         # Load the model.
         spandrel_model_info = context.models.load(self.image_to_image_model)
 
+        # Run the model on each tile.
         with spandrel_model_info as spandrel_model:
             assert isinstance(spandrel_model, SpandrelImageToImageModel)
 
-            # Prepare input image for inference.
-            image_tensor = SpandrelImageToImageModel.pil_to_tensor(image)
+            # Scale the tiles for re-assembling the final image.
+            scale = spandrel_model.scale
+            scaled_tiles = [self._scale_tile(tile, scale=scale) for tile in tiles]
+
+            # Prepare the output tensor.
+            _, channels, height, width = image_tensor.shape
+            output_tensor = torch.zeros(
+                (height * scale, width * scale, channels), dtype=torch.uint8, device=torch.device("cpu")
+            )
+
             image_tensor = image_tensor.to(device=spandrel_model.device, dtype=spandrel_model.dtype)
 
-            # Run inference.
-            image_tensor = spandrel_model.run(image_tensor)
+            for tile, scaled_tile in tqdm(list(zip(tiles, scaled_tiles, strict=True)), desc="Upscaling Tiles"):
+                # Extract the current tile from the input tensor.
+                input_tile = image_tensor[
+                    :, :, tile.coords.top : tile.coords.bottom, tile.coords.left : tile.coords.right
+                ].to(device=spandrel_model.device, dtype=spandrel_model.dtype)
+
+                # Run the model on the tile.
+                output_tile = spandrel_model.run(input_tile)
+
+                # Convert the output tile into the output tensor's format.
+                # (N, C, H, W) -> (C, H, W)
+                output_tile = output_tile.squeeze(0)
+                # (C, H, W) -> (H, W, C)
+                output_tile = output_tile.permute(1, 2, 0)
+                output_tile = output_tile.clamp(0, 1)
+                output_tile = (output_tile * 255).to(dtype=torch.uint8, device=torch.device("cpu"))
+
+                # Merge the output tile into the output tensor.
+                # We only keep half of the overlap on the top and left side of the tile. We do this in case there are
+                # edge artifacts. We don't bother with any 'blending' in the current implementation - for most upscalers
+                # it seems unnecessary, but we may find a need in the future.
+                top_overlap = scaled_tile.overlap.top // 2
+                left_overlap = scaled_tile.overlap.left // 2
+                output_tensor[
+                    scaled_tile.coords.top + top_overlap : scaled_tile.coords.bottom,
+                    scaled_tile.coords.left + left_overlap : scaled_tile.coords.right,
+                    :,
+                ] = output_tile[top_overlap:, left_overlap:, :]
 
         # Convert the output tensor to a PIL image.
-        pil_image = SpandrelImageToImageModel.tensor_to_pil(image_tensor)
+        np_image = output_tensor.detach().numpy().astype(np.uint8)
+        pil_image = Image.fromarray(np_image)
         image_dto = context.images.save(image=pil_image)
         return ImageOutput.build(image_dto)

invokeai/backend/spandrel_image_to_image_model.py

@@ -126,6 +126,11 @@ def dtype(self) -> torch.dtype:
         """The dtype of the underlying model."""
         return self._spandrel_model.dtype
 
+    @property
+    def scale(self) -> int:
+        """The scale of the model (e.g. 1x, 2x, 4x, etc.)."""
+        return self._spandrel_model.scale
+
     def calc_size(self) -> int:
         """Get size of the model in memory in bytes."""
         # HACK(ryand): Fix this issue with circular imports.