tidy(backend): clean up controlnet_utils

- Use the our adaptation of the HWC3 function with better types
- Extraction some of the util functions, name them better, add comments
- Improve type annotations
- Remove unreachable codepaths

invokeai/app/util/controlnet_utils.py

@@ -1,12 +1,13 @@
-from typing import Union
+from typing import Any, Literal, Union
 
 import cv2
 import numpy as np
 import torch
-from controlnet_aux.util import HWC3
-from diffusers.utils import PIL_INTERPOLATION
 from einops import rearrange
 from PIL import Image
+
+from invokeai.backend.image_util.util import nms, normalize_image_channel_count
+
 CONTROLNET_RESIZE_VALUES = Literal[
     "just_resize",
     "crop_resize",
@@ -75,17 +76,6 @@ def lvmin_thin(x, prunings=True):
     return y
 
 
-def nake_nms(x):
-    f1 = np.array([[0, 0, 0], [1, 1, 1], [0, 0, 0]], dtype=np.uint8)
-    f2 = np.array([[0, 1, 0], [0, 1, 0], [0, 1, 0]], dtype=np.uint8)
-    f3 = np.array([[1, 0, 0], [0, 1, 0], [0, 0, 1]], dtype=np.uint8)
-    f4 = np.array([[0, 0, 1], [0, 1, 0], [1, 0, 0]], dtype=np.uint8)
-    y = np.zeros_like(x)
-    for f in [f1, f2, f3, f4]:
-        np.putmask(y, cv2.dilate(x, kernel=f) == x, x)
-    return y
-
-
 ################################################################################
 # copied from Mikubill/sd-webui-controlnet external_code.py and modified for InvokeAI
 ################################################################################
@@ -141,98 +131,122 @@ def pixel_perfect_resolution(
     return int(np.round(estimation))
 
 
+def clone_contiguous(x: np.ndarray[Any, Any]) -> np.ndarray[Any, Any]:
+    """Get a memory-contiguous clone of the given numpy array, as a safety measure and to improve computation efficiency."""
+    return np.ascontiguousarray(x).copy()
+
+
+def np_img_to_torch(np_img: np.ndarray[Any, Any], device: torch.device) -> torch.Tensor:
+    """Convert a numpy image to a PyTorch tensor. The image is normalized to 0-1, rearranged to BCHW format and sent to
+    the specified device."""
+
+    torch_img = torch.from_numpy(np_img)
+    normalized = torch_img.float() / 255.0
+    bchw = rearrange(normalized, "h w c -> 1 c h w")
+    on_device = bchw.to(device)
+    return on_device.clone()
+
+
+def heuristic_resize(np_img: np.ndarray[Any, Any], size: tuple[int, int]) -> np.ndarray[Any, Any]:
+    """Resizes an image using a heuristic to choose the best resizing strategy.
+
+    - If the image appears to be an edge map, special handling will be applied to ensure the edges are not distorted.
+    - Single-pixel edge maps use NMS and thinning to keep the edges as single-pixel lines.
+    - Low-color-count images are resized with nearest-neighbor to preserve color information (for e.g. segmentation maps).
+    - The alpha channel is handled separately to ensure it is resized correctly.
+
+    Args:
+        np_img (np.ndarray): The input image.
+        size (tuple[int, int]): The target size for the image.
+
+    Returns:
+        np.ndarray: The resized image.
+
+    Adapted from https://github.com/Mikubill/sd-webui-controlnet.
+    """
+
+    # Return early if the image is already at the requested size
+    if np_img.shape[0] == size[1] and np_img.shape[1] == size[0]:
+        return np_img
+
+    # If the image has an alpha channel, separate it for special handling later.
+    inpaint_mask = None
+    if np_img.ndim == 3 and np_img.shape[2] == 4:
+        inpaint_mask = np_img[:, :, 3]
+        np_img = np_img[:, :, 0:3]
+
+    new_size_is_smaller = (size[0] * size[1]) < (np_img.shape[0] * np_img.shape[1])
+    new_size_is_bigger = (size[0] * size[1]) > (np_img.shape[0] * np_img.shape[1])
+    unique_color_count = np.unique(np_img.reshape(-1, np_img.shape[2]), axis=0).shape[0]
+    is_one_pixel_edge = False
+    is_binary = False
+
+    if unique_color_count == 2:
+        # If the image has only two colors, it is likely binary. Check if the image has one-pixel edges.
+        is_binary = np.min(np_img) < 16 and np.max(np_img) > 240
+        if is_binary:
+            eroded = cv2.erode(np_img, np.ones(shape=(3, 3), dtype=np.uint8), iterations=1)
+            dilated = cv2.dilate(eroded, np.ones(shape=(3, 3), dtype=np.uint8), iterations=1)
+            one_pixel_edge_count = np.where(dilated < np_img)[0].shape[0]
+            all_edge_count = np.where(np_img > 127)[0].shape[0]
+            is_one_pixel_edge = one_pixel_edge_count * 2 > all_edge_count
+
+    if 2 < unique_color_count < 200:
+        # With a low color count, we assume this is a map where exact colors are important. Near-neighbor preserves
+        # the colors as needed.
+        interpolation = cv2.INTER_NEAREST
+    elif new_size_is_smaller:
+        # This works best for downscaling
+        interpolation = cv2.INTER_AREA
+    else:
+        # Fall back for other cases
+        interpolation = cv2.INTER_CUBIC  # Must be CUBIC because we now use nms. NEVER CHANGE THIS
+
+    # This may be further transformed depending on the binary nature of the image.
+    resized = cv2.resize(np_img, size, interpolation=interpolation)
+
+    if inpaint_mask is not None:
+        # Resize the inpaint mask to match the resized image using the same interpolation method.
+        inpaint_mask = cv2.resize(inpaint_mask, size, interpolation=interpolation)
+
+    # If the image is binary, we will perform some additional processing to ensure the edges are preserved.
+    if is_binary:
+        resized = np.mean(resized.astype(np.float32), axis=2).clip(0, 255).astype(np.uint8)
+        if is_one_pixel_edge:
+            # Use NMS and thinning to keep the edges as single-pixel lines.
+            resized = nms(resized)
+            _, resized = cv2.threshold(resized, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
+            resized = lvmin_thin(resized, prunings=new_size_is_bigger)
+        else:
+            _, resized = cv2.threshold(resized, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
+        resized = np.stack([resized] * 3, axis=2)
+
+    # Restore the alpha channel if it was present.
+    if inpaint_mask is not None:
+        inpaint_mask = (inpaint_mask > 127).astype(np.float32) * 255.0
+        inpaint_mask = inpaint_mask[:, :, None].clip(0, 255).astype(np.uint8)
+        resized = np.concatenate([resized, inpaint_mask], axis=2)
+
+    return resized
+
+
 ###########################################################################
 # Copied from detectmap_proc method in scripts/detectmap_proc.py in Mikubill/sd-webui-controlnet
 #    modified for InvokeAI
 ###########################################################################
-# def detectmap_proc(detected_map, module, resize_mode, h, w):
+def np_img_resize(
-def np_img_resize(np_img: np.ndarray, resize_mode: str, h: int, w: int, device: torch.device = torch.device("cpu")):
+    np_img: np.ndarray,
-    # if 'inpaint' in module:
+    resize_mode: CONTROLNET_RESIZE_VALUES,
-    #     np_img = np_img.astype(np.float32)
+    h: int,
-    # else:
+    w: int,
-    #     np_img = HWC3(np_img)
+    device: torch.device = torch.device("cpu"),
-    np_img = HWC3(np_img)
+) -> tuple[torch.Tensor, np.ndarray[Any, Any]]:
+    np_img = normalize_image_channel_count(np_img)
 
-    def safe_numpy(x):
-        # A very safe method to make sure that Apple/Mac works
-        y = x
-
-        # below is very boring but do not change these. If you change these Apple or Mac may fail.
-        y = y.copy()
-        y = np.ascontiguousarray(y)
-        y = y.copy()
-        return y
-
-    def get_pytorch_control(x):
-        # A very safe method to make sure that Apple/Mac works
-        y = x
-
-        # below is very boring but do not change these. If you change these Apple or Mac may fail.
-        y = torch.from_numpy(y)
-        y = y.float() / 255.0
-        y = rearrange(y, "h w c -> 1 c h w")
-        y = y.clone()
-        # y = y.to(devices.get_device_for("controlnet"))
-        y = y.to(device)
-        y = y.clone()
-        return y
-
-    def high_quality_resize(x: np.ndarray, size):
-        # Written by lvmin
-        # Super high-quality control map up-scaling, considering binary, seg, and one-pixel edges
-        inpaint_mask = None
-        if x.ndim == 3 and x.shape[2] == 4:
-            inpaint_mask = x[:, :, 3]
-            x = x[:, :, 0:3]
-
-        new_size_is_smaller = (size[0] * size[1]) < (x.shape[0] * x.shape[1])
-        new_size_is_bigger = (size[0] * size[1]) > (x.shape[0] * x.shape[1])
-        unique_color_count = np.unique(x.reshape(-1, x.shape[2]), axis=0).shape[0]
-        is_one_pixel_edge = False
-        is_binary = False
-        if unique_color_count == 2:
-            is_binary = np.min(x) < 16 and np.max(x) > 240
-            if is_binary:
-                xc = x
-                xc = cv2.erode(xc, np.ones(shape=(3, 3), dtype=np.uint8), iterations=1)
-                xc = cv2.dilate(xc, np.ones(shape=(3, 3), dtype=np.uint8), iterations=1)
-                one_pixel_edge_count = np.where(xc < x)[0].shape[0]
-                all_edge_count = np.where(x > 127)[0].shape[0]
-                is_one_pixel_edge = one_pixel_edge_count * 2 > all_edge_count
-
-        if 2 < unique_color_count < 200:
-            interpolation = cv2.INTER_NEAREST
-        elif new_size_is_smaller:
-            interpolation = cv2.INTER_AREA
-        else:
-            interpolation = cv2.INTER_CUBIC  # Must be CUBIC because we now use nms. NEVER CHANGE THIS
-
-        y = cv2.resize(x, size, interpolation=interpolation)
-        if inpaint_mask is not None:
-            inpaint_mask = cv2.resize(inpaint_mask, size, interpolation=interpolation)
-
-        if is_binary:
-            y = np.mean(y.astype(np.float32), axis=2).clip(0, 255).astype(np.uint8)
-            if is_one_pixel_edge:
-                y = nake_nms(y)
-                _, y = cv2.threshold(y, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
-                y = lvmin_thin(y, prunings=new_size_is_bigger)
-            else:
-                _, y = cv2.threshold(y, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
-            y = np.stack([y] * 3, axis=2)
-
-        if inpaint_mask is not None:
-            inpaint_mask = (inpaint_mask > 127).astype(np.float32) * 255.0
-            inpaint_mask = inpaint_mask[:, :, None].clip(0, 255).astype(np.uint8)
-            y = np.concatenate([y, inpaint_mask], axis=2)
-
-        return y
-
-    # if resize_mode == external_code.ResizeMode.RESIZE:
     if resize_mode == "just_resize":  # RESIZE
-        np_img = high_quality_resize(np_img, (w, h))
+        np_img = heuristic_resize(np_img, (w, h))
-        np_img = safe_numpy(np_img)
+        np_img = clone_contiguous(np_img)
-        return get_pytorch_control(np_img), np_img
+        return np_img_to_torch(np_img, device), np_img
 
     old_h, old_w, _ = np_img.shape
     old_w = float(old_w)
@@ -243,7 +257,6 @@ def np_img_resize(np_img: np.ndarray, resize_mode: str, h: int, w: int, device:
     def safeint(x: Union[int, float]) -> int:
         return int(np.round(x))
 
-    # if resize_mode == external_code.ResizeMode.OUTER_FIT:
     if resize_mode == "fill_resize":  # OUTER_FIT
         k = min(k0, k1)
         borders = np.concatenate([np_img[0, :, :], np_img[-1, :, :], np_img[:, 0, :], np_img[:, -1, :]], axis=0)
@@ -252,23 +265,23 @@ def np_img_resize(np_img: np.ndarray, resize_mode: str, h: int, w: int, device:
             # Inpaint hijack
             high_quality_border_color[3] = 255
         high_quality_background = np.tile(high_quality_border_color[None, None], [h, w, 1])
-        np_img = high_quality_resize(np_img, (safeint(old_w * k), safeint(old_h * k)))
+        np_img = heuristic_resize(np_img, (safeint(old_w * k), safeint(old_h * k)))
         new_h, new_w, _ = np_img.shape
         pad_h = max(0, (h - new_h) // 2)
         pad_w = max(0, (w - new_w) // 2)
         high_quality_background[pad_h : pad_h + new_h, pad_w : pad_w + new_w] = np_img
         np_img = high_quality_background
-        np_img = safe_numpy(np_img)
+        np_img = clone_contiguous(np_img)
-        return get_pytorch_control(np_img), np_img
+        return np_img_to_torch(np_img, device), np_img
     else:  # resize_mode == "crop_resize"  (INNER_FIT)
         k = max(k0, k1)
-        np_img = high_quality_resize(np_img, (safeint(old_w * k), safeint(old_h * k)))
+        np_img = heuristic_resize(np_img, (safeint(old_w * k), safeint(old_h * k)))
         new_h, new_w, _ = np_img.shape
         pad_h = max(0, (new_h - h) // 2)
         pad_w = max(0, (new_w - w) // 2)
         np_img = np_img[pad_h : pad_h + h, pad_w : pad_w + w]
-        np_img = safe_numpy(np_img)
+        np_img = clone_contiguous(np_img)
-        return get_pytorch_control(np_img), np_img
+        return np_img_to_torch(np_img, device), np_img
 
 
 def prepare_control_image(
@@ -276,12 +289,12 @@ def prepare_control_image(
     width: int,
     height: int,
     num_channels: int = 3,
-    device="cuda",
+    device: str = "cuda",
-    dtype=torch.float16,
+    dtype: torch.dtype = torch.float16,
-    do_classifier_free_guidance=True,
+    control_mode: CONTROLNET_MODE_VALUES = "balanced",
-    control_mode="balanced",
+    resize_mode: CONTROLNET_RESIZE_VALUES = "just_resize_simple",
-    resize_mode="just_resize_simple",
+    do_classifier_free_guidance: bool = True,
-):
+) -> torch.Tensor:
     """Pre-process images for ControlNets or T2I-Adapters.
 
     Args:
@@ -299,26 +312,15 @@ def prepare_control_image(
         resize_mode (str, optional): Defaults to "just_resize_simple".
 
     Raises:
-        NotImplementedError: If resize_mode == "crop_resize_simple".
-        NotImplementedError: If resize_mode == "fill_resize_simple".
         ValueError: If `resize_mode` is not recognized.
         ValueError: If `num_channels` is out of range.
 
     Returns:
         torch.Tensor: The pre-processed input tensor.
     """
-    if (
-        resize_mode == "just_resize_simple"
-        or resize_mode == "crop_resize_simple"
-        or resize_mode == "fill_resize_simple"
-    ):
-        image = image.convert("RGB")
     if resize_mode == "just_resize_simple":
-            image = image.resize((width, height), resample=PIL_INTERPOLATION["lanczos"])
+        image = image.convert("RGB")
-        elif resize_mode == "crop_resize_simple":
+        image = image.resize((width, height), resample=Image.LANCZOS)
-            raise NotImplementedError(f"prepare_control_image is not implemented for resize_mode='{resize_mode}'.")
-        elif resize_mode == "fill_resize_simple":
-            raise NotImplementedError(f"prepare_control_image is not implemented for resize_mode='{resize_mode}'.")
         nimage = np.array(image)
         nimage = nimage[None, :]
         nimage = np.concatenate([nimage], axis=0)
@@ -335,8 +337,7 @@ def prepare_control_image(
             resize_mode=resize_mode,
             h=height,
             w=width,
-            # device=torch.device('cpu')
+            device=torch.device(device),
-            device=device,
         )
     else:
         raise ValueError(f"Unsupported resize_mode: '{resize_mode}'.")