def METHOD_NAME(self, main):
    """
    Args:
        main (ModuleBase):
    Returns:
        np.ndarray: Shape (n,), dtype bool.
    """
    image = main.image_crop(self.area)
    image = color_similarity_2d(image, color=self.color)
    mask = np.max(image, axis=1 if self.is_vertical else 0) > self.color_threshold
    self.length = np.sum(mask)
    return mask