Add a canny preprocessor node.

comfy_extras/nodes_canny.py

+#From https://github.com/kornia/kornia
+import math
+
+import torch
+import torch.nn.functional as F
+
+
+def get_canny_nms_kernel(device=None, dtype=None):
+    """Utility function that returns 3x3 kernels for the Canny Non-maximal suppression."""
+    return torch.tensor(
+        [
+            [[[0.0, 0.0, 0.0], [0.0, 1.0, -1.0], [0.0, 0.0, 0.0]]],
+            [[[0.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, -1.0]]],
+            [[[0.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, -1.0, 0.0]]],
+            [[[0.0, 0.0, 0.0], [0.0, 1.0, 0.0], [-1.0, 0.0, 0.0]]],
+            [[[0.0, 0.0, 0.0], [-1.0, 1.0, 0.0], [0.0, 0.0, 0.0]]],
+            [[[-1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 0.0]]],
+            [[[0.0, -1.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 0.0]]],
+            [[[0.0, 0.0, -1.0], [0.0, 1.0, 0.0], [0.0, 0.0, 0.0]]],
+        ],
+        device=device,
+        dtype=dtype,
+    )
+
+
+def get_hysteresis_kernel(device=None, dtype=None):
+    """Utility function that returns the 3x3 kernels for the Canny hysteresis."""
+    return torch.tensor(
+        [
+            [[[0.0, 0.0, 0.0], [0.0, 0.0, 1.0], [0.0, 0.0, 0.0]]],
+            [[[0.0, 0.0, 0.0], [0.0, 0.0, 0.0], [0.0, 0.0, 1.0]]],
+            [[[0.0, 0.0, 0.0], [0.0, 0.0, 0.0], [0.0, 1.0, 0.0]]],
+            [[[0.0, 0.0, 0.0], [0.0, 0.0, 0.0], [1.0, 0.0, 0.0]]],
+            [[[0.0, 0.0, 0.0], [1.0, 0.0, 0.0], [0.0, 0.0, 0.0]]],
+            [[[1.0, 0.0, 0.0], [0.0, 0.0, 0.0], [0.0, 0.0, 0.0]]],
+            [[[0.0, 1.0, 0.0], [0.0, 0.0, 0.0], [0.0, 0.0, 0.0]]],
+            [[[0.0, 0.0, 1.0], [0.0, 0.0, 0.0], [0.0, 0.0, 0.0]]],
+        ],
+        device=device,
+        dtype=dtype,
+    )
+
+def gaussian_blur_2d(img, kernel_size, sigma):
+    ksize_half = (kernel_size - 1) * 0.5
+
+    x = torch.linspace(-ksize_half, ksize_half, steps=kernel_size)
+
+    pdf = torch.exp(-0.5 * (x / sigma).pow(2))
+
+    x_kernel = pdf / pdf.sum()
+    x_kernel = x_kernel.to(device=img.device, dtype=img.dtype)
+
+    kernel2d = torch.mm(x_kernel[:, None], x_kernel[None, :])
+    kernel2d = kernel2d.expand(img.shape[-3], 1, kernel2d.shape[0], kernel2d.shape[1])
+
+    padding = [kernel_size // 2, kernel_size // 2, kernel_size // 2, kernel_size // 2]
+
+    img = torch.nn.functional.pad(img, padding, mode="reflect")
+    img = torch.nn.functional.conv2d(img, kernel2d, groups=img.shape[-3])
+
+    return img
+
+def get_sobel_kernel2d(device=None, dtype=None):
+    kernel_x = torch.tensor([[-1.0, 0.0, 1.0], [-2.0, 0.0, 2.0], [-1.0, 0.0, 1.0]], device=device, dtype=dtype)
+    kernel_y = kernel_x.transpose(0, 1)
+    return torch.stack([kernel_x, kernel_y])
+
+def spatial_gradient(input, normalized: bool = True):
+    r"""Compute the first order image derivative in both x and y using a Sobel operator.
+    .. image:: _static/img/spatial_gradient.png
+    Args:
+        input: input image tensor with shape :math:`(B, C, H, W)`.
+        mode: derivatives modality, can be: `sobel` or `diff`.
+        order: the order of the derivatives.
+        normalized: whether the output is normalized.
+    Return:
+        the derivatives of the input feature map. with shape :math:`(B, C, 2, H, W)`.
+    .. note::
+       See a working example `here <https://kornia-tutorials.readthedocs.io/en/latest/
+       filtering_edges.html>`__.
+    Examples:
+        >>> input = torch.rand(1, 3, 4, 4)
+        >>> output = spatial_gradient(input)  # 1x3x2x4x4
+        >>> output.shape
+        torch.Size([1, 3, 2, 4, 4])
+    """
+    # KORNIA_CHECK_IS_TENSOR(input)
+    # KORNIA_CHECK_SHAPE(input, ['B', 'C', 'H', 'W'])
+
+    # allocate kernel
+    kernel = get_sobel_kernel2d(device=input.device, dtype=input.dtype)
+    if normalized:
+        kernel = normalize_kernel2d(kernel)
+
+    # prepare kernel
+    b, c, h, w = input.shape
+    tmp_kernel = kernel[:, None, ...]
+
+    # Pad with "replicate for spatial dims, but with zeros for channel
+    spatial_pad = [kernel.size(1) // 2, kernel.size(1) // 2, kernel.size(2) // 2, kernel.size(2) // 2]
+    out_channels: int = 2
+    padded_inp = torch.nn.functional.pad(input.reshape(b * c, 1, h, w), spatial_pad, 'replicate')
+    out = F.conv2d(padded_inp, tmp_kernel, groups=1, padding=0, stride=1)
+    return out.reshape(b, c, out_channels, h, w)
+
+def rgb_to_grayscale(image, rgb_weights = None):
+    r"""Convert a RGB image to grayscale version of image.
+
+    .. image:: _static/img/rgb_to_grayscale.png
+
+    The image data is assumed to be in the range of (0, 1).
+
+    Args:
+        image: RGB image to be converted to grayscale with shape :math:`(*,3,H,W)`.
+        rgb_weights: Weights that will be applied on each channel (RGB).
+            The sum of the weights should add up to one.
+    Returns:
+        grayscale version of the image with shape :math:`(*,1,H,W)`.
+
+    .. note::
+       See a working example `here <https://kornia-tutorials.readthedocs.io/en/latest/
+       color_conversions.html>`__.
+
+    Example:
+        >>> input = torch.rand(2, 3, 4, 5)
+        >>> gray = rgb_to_grayscale(input) # 2x1x4x5
+    """
+
+    if len(image.shape) < 3 or image.shape[-3] != 3:
+        raise ValueError(f"Input size must have a shape of (*, 3, H, W). Got {image.shape}")
+
+    if rgb_weights is None:
+        # 8 bit images
+        if image.dtype == torch.uint8:
+            rgb_weights = torch.tensor([76, 150, 29], device=image.device, dtype=torch.uint8)
+        # floating point images
+        elif image.dtype in (torch.float16, torch.float32, torch.float64):
+            rgb_weights = torch.tensor([0.299, 0.587, 0.114], device=image.device, dtype=image.dtype)
+        else:
+            raise TypeError(f"Unknown data type: {image.dtype}")
+    else:
+        # is tensor that we make sure is in the same device/dtype
+        rgb_weights = rgb_weights.to(image)
+
+    # unpack the color image channels with RGB order
+    r: Tensor = image[..., 0:1, :, :]
+    g: Tensor = image[..., 1:2, :, :]
+    b: Tensor = image[..., 2:3, :, :]
+
+    w_r, w_g, w_b = rgb_weights.unbind()
+    return w_r * r + w_g * g + w_b * b
+
+def canny(
+    input,
+    low_threshold = 0.1,
+    high_threshold = 0.2,
+    kernel_size  = 5,
+    sigma = 1,
+    hysteresis = True,
+    eps = 1e-6,
+):
+    r"""Find edges of the input image and filters them using the Canny algorithm.
+    .. image:: _static/img/canny.png
+    Args:
+        input: input image tensor with shape :math:`(B,C,H,W)`.
+        low_threshold: lower threshold for the hysteresis procedure.
+        high_threshold: upper threshold for the hysteresis procedure.
+        kernel_size: the size of the kernel for the gaussian blur.
+        sigma: the standard deviation of the kernel for the gaussian blur.
+        hysteresis: if True, applies the hysteresis edge tracking.
+            Otherwise, the edges are divided between weak (0.5) and strong (1) edges.
+        eps: regularization number to avoid NaN during backprop.
+    Returns:
+        - the canny edge magnitudes map, shape of :math:`(B,1,H,W)`.
+        - the canny edge detection filtered by thresholds and hysteresis, shape of :math:`(B,1,H,W)`.
+    .. note::
+       See a working example `here <https://kornia-tutorials.readthedocs.io/en/latest/
+       canny.html>`__.
+    Example:
+        >>> input = torch.rand(5, 3, 4, 4)
+        >>> magnitude, edges = canny(input)  # 5x3x4x4
+        >>> magnitude.shape
+        torch.Size([5, 1, 4, 4])
+        >>> edges.shape
+        torch.Size([5, 1, 4, 4])
+    """
+    # KORNIA_CHECK_IS_TENSOR(input)
+    # KORNIA_CHECK_SHAPE(input, ['B', 'C', 'H', 'W'])
+    # KORNIA_CHECK(
+    #     low_threshold <= high_threshold,
+    #     "Invalid input thresholds. low_threshold should be smaller than the high_threshold. Got: "
+    #     f"{low_threshold}>{high_threshold}",
+    # )
+    # KORNIA_CHECK(0 < low_threshold < 1, f'Invalid low threshold. Should be in range (0, 1). Got: {low_threshold}')
+    # KORNIA_CHECK(0 < high_threshold < 1, f'Invalid high threshold. Should be in range (0, 1). Got: {high_threshold}')
+
+    device = input.device
+    dtype = input.dtype
+
+    # To Grayscale
+    if input.shape[1] == 3:
+        input = rgb_to_grayscale(input)
+
+    # Gaussian filter
+    blurred: Tensor = gaussian_blur_2d(input, kernel_size, sigma)
+
+    # Compute the gradients
+    gradients: Tensor = spatial_gradient(blurred, normalized=False)
+
+    # Unpack the edges
+    gx: Tensor = gradients[:, :, 0]
+    gy: Tensor = gradients[:, :, 1]
+
+    # Compute gradient magnitude and angle
+    magnitude: Tensor = torch.sqrt(gx * gx + gy * gy + eps)
+    angle: Tensor = torch.atan2(gy, gx)
+
+    # Radians to Degrees
+    angle = 180.0 * angle / math.pi
+
+    # Round angle to the nearest 45 degree
+    angle = torch.round(angle / 45) * 45
+
+    # Non-maximal suppression
+    nms_kernels: Tensor = get_canny_nms_kernel(device, dtype)
+    nms_magnitude: Tensor = F.conv2d(magnitude, nms_kernels, padding=nms_kernels.shape[-1] // 2)
+
+    # Get the indices for both directions
+    positive_idx: Tensor = (angle / 45) % 8
+    positive_idx = positive_idx.long()
+
+    negative_idx: Tensor = ((angle / 45) + 4) % 8
+    negative_idx = negative_idx.long()
+
+    # Apply the non-maximum suppression to the different directions
+    channel_select_filtered_positive: Tensor = torch.gather(nms_magnitude, 1, positive_idx)
+    channel_select_filtered_negative: Tensor = torch.gather(nms_magnitude, 1, negative_idx)
+
+    channel_select_filtered: Tensor = torch.stack(
+        [channel_select_filtered_positive, channel_select_filtered_negative], 1
+    )
+
+    is_max: Tensor = channel_select_filtered.min(dim=1)[0] > 0.0
+
+    magnitude = magnitude * is_max
+
+    # Threshold
+    edges: Tensor = F.threshold(magnitude, low_threshold, 0.0)
+
+    low: Tensor = magnitude > low_threshold
+    high: Tensor = magnitude > high_threshold
+
+    edges = low * 0.5 + high * 0.5
+    edges = edges.to(dtype)
+
+    # Hysteresis
+    if hysteresis:
+        edges_old: Tensor = -torch.ones(edges.shape, device=edges.device, dtype=dtype)
+        hysteresis_kernels: Tensor = get_hysteresis_kernel(device, dtype)
+
+        while ((edges_old - edges).abs() != 0).any():
+            weak: Tensor = (edges == 0.5).float()
+            strong: Tensor = (edges == 1).float()
+
+            hysteresis_magnitude: Tensor = F.conv2d(
+                edges, hysteresis_kernels, padding=hysteresis_kernels.shape[-1] // 2
+            )
+            hysteresis_magnitude = (hysteresis_magnitude == 1).any(1, keepdim=True).to(dtype)
+            hysteresis_magnitude = hysteresis_magnitude * weak + strong
+
+            edges_old = edges.clone()
+            edges = hysteresis_magnitude + (hysteresis_magnitude == 0) * weak * 0.5
+
+        edges = hysteresis_magnitude
+
+    return magnitude, edges
+
+
+class Canny:
+    @classmethod
+    def INPUT_TYPES(s):
+        return {"required": {"image": ("IMAGE",),
+                                "low_threshold": ("FLOAT", {"default": 0.4, "min": 0.01, "max": 0.99, "step": 0.01}),
+                                "high_threshold": ("FLOAT", {"default": 0.8, "min": 0.01, "max": 0.99, "step": 0.01})
+                                }}
+
+    RETURN_TYPES = ("IMAGE",)
+    FUNCTION = "detect_edge"
+
+    CATEGORY = "image/preprocessors"
+
+    def detect_edge(self, image, low_threshold, high_threshold):
+        output = canny(image.movedim(-1, 1), low_threshold, high_threshold)
+        img_out = output[1].repeat(1, 3, 1, 1).movedim(1, -1)
+        return (img_out,)
+
+NODE_CLASS_MAPPINGS = {
+    "Canny": Canny,
+}

nodes.py

@@ -1562,4 +1562,5 @@ def init_custom_nodes():
     load_custom_node(os.path.join(os.path.join(os.path.dirname(os.path.realpath(__file__)), "comfy_extras"), "nodes_model_merging.py"))
     load_custom_node(os.path.join(os.path.join(os.path.dirname(os.path.realpath(__file__)), "comfy_extras"), "nodes_tomesd.py"))
     load_custom_node(os.path.join(os.path.join(os.path.dirname(os.path.realpath(__file__)), "comfy_extras"), "nodes_clip_sdxl.py"))
+    load_custom_node(os.path.join(os.path.join(os.path.dirname(os.path.realpath(__file__)), "comfy_extras"), "nodes_canny.py"))
     load_custom_nodes()