Make T2I-Adapter downscale padding match the UNet (#5435)

* Update get_dummy_inputs(...) in T2I-Adapter tests to take image height and width as params.

* Update the T2I-Adapter unit tests to run with the standard number of UNet down blocks so that all T2I-Adapter down blocks get exercised.

* Update the T2I-Adapter down blocks to better match the padding behavior of the UNet.

* Revert "Update the T2I-Adapter unit tests to run with the standard number of UNet down blocks so that all T2I-Adapter down blocks get exercised."

This reverts commit 6d4a060.

* Create  utility functions for testing the T2I-Adapter downscaling bahevior.

* (minor) Improve readability with an intermediate named variable.

* Statically parameterize  T2I-Adapter test dimensions rather than generating them dynamically.

* Fix static checks.

---------

Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

src/diffusers/models/adapter.py

@@ -20,7 +20,6 @@
 from ..configuration_utils import ConfigMixin, register_to_config
 from ..utils import logging
 from .modeling_utils import ModelMixin
-from .resnet import Downsample2D
 
 
 logger = logging.get_logger(__name__)
@@ -51,24 +50,28 @@ def __init__(self, adapters: List["T2IAdapter"]):
         if len(adapters) == 1:
             raise ValueError("For a single adapter, please use the `T2IAdapter` class instead of `MultiAdapter`")
 
-        # The outputs from each adapter are added together with a weight
-        # This means that the change in dimenstions from downsampling must
-        # be the same for all adapters. Inductively, it also means the total
-        # downscale factor must also be the same for all adapters.
-
+        # The outputs from each adapter are added together with a weight.
+        # This means that the change in dimensions from downsampling must
+        # be the same for all adapters. Inductively, it also means the
+        # downscale_factor and total_downscale_factor must be the same for all
+        # adapters.
         first_adapter_total_downscale_factor = adapters[0].total_downscale_factor
-
+        first_adapter_downscale_factor = adapters[0].downscale_factor
         for idx in range(1, len(adapters)):
-            adapter_idx_total_downscale_factor = adapters[idx].total_downscale_factor
-
-            if adapter_idx_total_downscale_factor != first_adapter_total_downscale_factor:
+            if (
+                adapters[idx].total_downscale_factor != first_adapter_total_downscale_factor
+                or adapters[idx].downscale_factor != first_adapter_downscale_factor
+            ):
                 raise ValueError(
-                    f"Expecting all adapters to have the same total_downscale_factor, "
-                    f"but got adapters[0].total_downscale_factor={first_adapter_total_downscale_factor} and "
-                    f"adapter[`{idx}`]={adapter_idx_total_downscale_factor}"
+                    f"Expecting all adapters to have the same downscaling behavior, but got:\n"
+                    f"adapters[0].total_downscale_factor={first_adapter_total_downscale_factor}\n"
+                    f"adapters[0].downscale_factor={first_adapter_downscale_factor}\n"
+                    f"adapter[`{idx}`].total_downscale_factor={adapters[idx].total_downscale_factor}\n"
+                    f"adapter[`{idx}`].downscale_factor={adapters[idx].downscale_factor}"
                 )
 
-        self.total_downscale_factor = adapters[0].total_downscale_factor
+        self.total_downscale_factor = first_adapter_total_downscale_factor
+        self.downscale_factor = first_adapter_downscale_factor
 
     def forward(self, xs: torch.Tensor, adapter_weights: Optional[List[float]] = None) -> List[torch.Tensor]:
         r"""
@@ -274,6 +277,13 @@ def forward(self, x: torch.Tensor) -> List[torch.Tensor]:
     def total_downscale_factor(self):
         return self.adapter.total_downscale_factor
 
+    @property
+    def downscale_factor(self):
+        """The downscale factor applied in the T2I-Adapter's initial pixel unshuffle operation. If an input image's dimensions are
+        not evenly divisible by the downscale_factor then an exception will be raised.
+        """
+        return self.adapter.unshuffle.downscale_factor
+
 
 # full adapter
 
@@ -399,7 +409,7 @@ def __init__(self, in_channels: int, out_channels: int, num_res_blocks: int, dow
 
         self.downsample = None
         if down:
-            self.downsample = Downsample2D(in_channels)
+            self.downsample = nn.AvgPool2d(kernel_size=2, stride=2, ceil_mode=True)
 
         self.in_conv = None
         if in_channels != out_channels:
@@ -526,7 +536,7 @@ def __init__(self, in_channels: int, out_channels: int, num_res_blocks: int, dow
 
         self.downsample = None
         if down:
-            self.downsample = Downsample2D(in_channels)
+            self.downsample = nn.AvgPool2d(kernel_size=2, stride=2, ceil_mode=True)
 
         self.in_conv = nn.Conv2d(in_channels, mid_channels, kernel_size=1)
         self.resnets = nn.Sequential(*[LightAdapterResnetBlock(mid_channels) for _ in range(num_res_blocks)])

src/diffusers/pipelines/t2i_adapter/pipeline_stable_diffusion_adapter.py

@@ -568,17 +568,17 @@ def _default_height_width(self, height, width, image):
             elif isinstance(image, torch.Tensor):
                 height = image.shape[-2]
 
-            # round down to nearest multiple of `self.adapter.total_downscale_factor`
-            height = (height // self.adapter.total_downscale_factor) * self.adapter.total_downscale_factor
+            # round down to nearest multiple of `self.adapter.downscale_factor`
+            height = (height // self.adapter.downscale_factor) * self.adapter.downscale_factor
 
         if width is None:
             if isinstance(image, PIL.Image.Image):
                 width = image.width
             elif isinstance(image, torch.Tensor):
                 width = image.shape[-1]
 
-            # round down to nearest multiple of `self.adapter.total_downscale_factor`
-            width = (width // self.adapter.total_downscale_factor) * self.adapter.total_downscale_factor
+            # round down to nearest multiple of `self.adapter.downscale_factor`
+            width = (width // self.adapter.downscale_factor) * self.adapter.downscale_factor
 
         return height, width
 

src/diffusers/pipelines/t2i_adapter/pipeline_stable_diffusion_xl_adapter.py

@@ -622,17 +622,17 @@ def _default_height_width(self, height, width, image):
             elif isinstance(image, torch.Tensor):
                 height = image.shape[-2]
 
-            # round down to nearest multiple of `self.adapter.total_downscale_factor`
-            height = (height // self.adapter.total_downscale_factor) * self.adapter.total_downscale_factor
+            # round down to nearest multiple of `self.adapter.downscale_factor`
+            height = (height // self.adapter.downscale_factor) * self.adapter.downscale_factor
 
         if width is None:
             if isinstance(image, PIL.Image.Image):
                 width = image.width
             elif isinstance(image, torch.Tensor):
                 width = image.shape[-1]
 
-            # round down to nearest multiple of `self.adapter.total_downscale_factor`
-            width = (width // self.adapter.total_downscale_factor) * self.adapter.total_downscale_factor
+            # round down to nearest multiple of `self.adapter.downscale_factor`
+            width = (width // self.adapter.downscale_factor) * self.adapter.downscale_factor
 
         return height, width
 

tests/pipelines/stable_diffusion/test_stable_diffusion_adapter.py

@@ -19,6 +19,7 @@
 
 import numpy as np
 import torch
+from parameterized import parameterized
 from transformers import CLIPTextConfig, CLIPTextModel, CLIPTokenizer
 
 import diffusers
@@ -137,11 +138,100 @@ def get_dummy_components(self, adapter_type):
         }
         return components
 
-    def get_dummy_inputs(self, device, seed=0, num_images=1):
+    def get_dummy_components_with_full_downscaling(self, adapter_type):
+        """Get dummy components with x8 VAE downscaling and 4 UNet down blocks.
+        These dummy components are intended to fully-exercise the T2I-Adapter
+        downscaling behavior.
+        """
+        torch.manual_seed(0)
+        unet = UNet2DConditionModel(
+            block_out_channels=(32, 32, 32, 64),
+            layers_per_block=2,
+            sample_size=32,
+            in_channels=4,
+            out_channels=4,
+            down_block_types=("CrossAttnDownBlock2D", "CrossAttnDownBlock2D", "CrossAttnDownBlock2D", "DownBlock2D"),
+            up_block_types=("UpBlock2D", "CrossAttnUpBlock2D", "CrossAttnUpBlock2D", "CrossAttnUpBlock2D"),
+            cross_attention_dim=32,
+        )
+        scheduler = PNDMScheduler(skip_prk_steps=True)
+        torch.manual_seed(0)
+        vae = AutoencoderKL(
+            block_out_channels=[32, 32, 32, 64],
+            in_channels=3,
+            out_channels=3,
+            down_block_types=["DownEncoderBlock2D", "DownEncoderBlock2D", "DownEncoderBlock2D", "DownEncoderBlock2D"],
+            up_block_types=["UpDecoderBlock2D", "UpDecoderBlock2D", "UpDecoderBlock2D", "UpDecoderBlock2D"],
+            latent_channels=4,
+        )
+        torch.manual_seed(0)
+        text_encoder_config = CLIPTextConfig(
+            bos_token_id=0,
+            eos_token_id=2,
+            hidden_size=32,
+            intermediate_size=37,
+            layer_norm_eps=1e-05,
+            num_attention_heads=4,
+            num_hidden_layers=5,
+            pad_token_id=1,
+            vocab_size=1000,
+        )
+        text_encoder = CLIPTextModel(text_encoder_config)
+        tokenizer = CLIPTokenizer.from_pretrained("hf-internal-testing/tiny-random-clip")
+
+        torch.manual_seed(0)
+
+        if adapter_type == "full_adapter" or adapter_type == "light_adapter":
+            adapter = T2IAdapter(
+                in_channels=3,
+                channels=[32, 32, 32, 64],
+                num_res_blocks=2,
+                downscale_factor=8,
+                adapter_type=adapter_type,
+            )
+        elif adapter_type == "multi_adapter":
+            adapter = MultiAdapter(
+                [
+                    T2IAdapter(
+                        in_channels=3,
+                        channels=[32, 32, 32, 64],
+                        num_res_blocks=2,
+                        downscale_factor=8,
+                        adapter_type="full_adapter",
+                    ),
+                    T2IAdapter(
+                        in_channels=3,
+                        channels=[32, 32, 32, 64],
+                        num_res_blocks=2,
+                        downscale_factor=8,
+                        adapter_type="full_adapter",
+                    ),
+                ]
+            )
+        else:
+            raise ValueError(
+                f"Unknown adapter type: {adapter_type}, must be one of 'full_adapter', 'light_adapter', or 'multi_adapter''"
+            )
+
+        components = {
+            "adapter": adapter,
+            "unet": unet,
+            "scheduler": scheduler,
+            "vae": vae,
+            "text_encoder": text_encoder,
+            "tokenizer": tokenizer,
+            "safety_checker": None,
+            "feature_extractor": None,
+        }
+        return components
+
+    def get_dummy_inputs(self, device, seed=0, height=64, width=64, num_images=1):
         if num_images == 1:
-            image = floats_tensor((1, 3, 64, 64), rng=random.Random(seed)).to(device)
+            image = floats_tensor((1, 3, height, width), rng=random.Random(seed)).to(device)
         else:
-            image = [floats_tensor((1, 3, 64, 64), rng=random.Random(seed)).to(device) for _ in range(num_images)]
+            image = [
+                floats_tensor((1, 3, height, width), rng=random.Random(seed)).to(device) for _ in range(num_images)
+            ]
 
         if str(device).startswith("mps"):
             generator = torch.manual_seed(seed)
@@ -170,11 +260,45 @@ def test_xformers_attention_forwardGenerator_pass(self):
     def test_inference_batch_single_identical(self):
         self._test_inference_batch_single_identical(expected_max_diff=2e-3)
 
+    @parameterized.expand(
+        [
+            # (dim=264) The internal feature map will be 33x33 after initial pixel unshuffling (downscaled x8).
+            ((4 * 8 + 1) * 8),
+            # (dim=272) The internal feature map will be 17x17 after the first T2I down block (downscaled x16).
+            ((4 * 4 + 1) * 16),
+            # (dim=288) The internal feature map will be 9x9 after the second T2I down block (downscaled x32).
+            ((4 * 2 + 1) * 32),
+            # (dim=320) The internal feature map will be 5x5 after the third T2I down block (downscaled x64).
+            ((4 * 1 + 1) * 64),
+        ]
+    )
+    def test_multiple_image_dimensions(self, dim):
+        """Test that the T2I-Adapter pipeline supports any input dimension that
+        is divisible by the adapter's `downscale_factor`. This test was added in
+        response to an issue where the T2I Adapter's downscaling padding
+        behavior did not match the UNet's behavior.
+
+        Note that we have selected `dim` values to produce odd resolutions at
+        each downscaling level.
+        """
+        components = self.get_dummy_components_with_full_downscaling()
+        sd_pipe = StableDiffusionAdapterPipeline(**components)
+        sd_pipe = sd_pipe.to(torch_device)
+        sd_pipe.set_progress_bar_config(disable=None)
+
+        inputs = self.get_dummy_inputs(torch_device, height=dim, width=dim)
+        image = sd_pipe(**inputs).images
+
+        assert image.shape == (1, dim, dim, 3)
+
 
 class StableDiffusionFullAdapterPipelineFastTests(AdapterTests, PipelineTesterMixin, unittest.TestCase):
     def get_dummy_components(self):
         return super().get_dummy_components("full_adapter")
 
+    def get_dummy_components_with_full_downscaling(self):
+        return super().get_dummy_components_with_full_downscaling("full_adapter")
+
     def test_stable_diffusion_adapter_default_case(self):
         device = "cpu"  # ensure determinism for the device-dependent torch.Generator
         components = self.get_dummy_components()
@@ -195,6 +319,9 @@ class StableDiffusionLightAdapterPipelineFastTests(AdapterTests, PipelineTesterM
     def get_dummy_components(self):
         return super().get_dummy_components("light_adapter")
 
+    def get_dummy_components_with_full_downscaling(self):
+        return super().get_dummy_components_with_full_downscaling("light_adapter")
+
     def test_stable_diffusion_adapter_default_case(self):
         device = "cpu"  # ensure determinism for the device-dependent torch.Generator
         components = self.get_dummy_components()
@@ -215,8 +342,11 @@ class StableDiffusionMultiAdapterPipelineFastTests(AdapterTests, PipelineTesterM
     def get_dummy_components(self):
         return super().get_dummy_components("multi_adapter")
 
-    def get_dummy_inputs(self, device, seed=0):
-        inputs = super().get_dummy_inputs(device, seed, num_images=2)
+    def get_dummy_components_with_full_downscaling(self):
+        return super().get_dummy_components_with_full_downscaling("multi_adapter")
+
+    def get_dummy_inputs(self, device, height=64, width=64, seed=0):
+        inputs = super().get_dummy_inputs(device, seed, height=height, width=width, num_images=2)
         inputs["adapter_conditioning_scale"] = [0.5, 0.5]
         return inputs