import cv2
import numpy as np
from flojoy import Image, flojoy
from PIL import Image as PILImage
from PIL import ImageFilter


@flojoy(deps={"opencv-python": "4.8.0"})
def EDGE_DETECTION(default: Image) -> Image:
    """The EDGE_DETECTION node detects edges in the image that was passed to it.

    This is done through the Pillow image filter, FIND_EDGES.

    Note that the image is converted to greyscale during this processing.

    Parameters
    ----------
    default : Image
        The input image to apply edge detection to.

    Returns
    -------
    Image
        The image with detected edges in white.
    """

    r = default.r
    g = default.g
    b = default.b
    a = default.a

    if a is not None:
        rgba_image = np.stack((r, g, b, a), axis=2)

    else:
        rgba_image = np.stack((r, g, b), axis=2)

    try:
        image = PILImage.fromarray(rgba_image)
        image = image.convert("L").filter(ImageFilter.FIND_EDGES).convert("RGB")
        image = np.array(image)

        try:
            r, g, b, a = cv2.split(image)
        except:
            r, g, b = cv2.split(image)
        if a is None:
            a = None
        return Image(
            r=r,
            g=g,
            b=b,
            a=a,
        )
    except Exception as e:
        raise e

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