def crop_border(img, border_x, border_y):
    """Crop the border of an image. Due to peripheral blurring.

    Args:
        img (np.ndarray): input image
        border_x (int): number of pixels to crop on each side of x border
        border_y (int): number of pixels to crop on each side of y border
    Returns:
        np.ndarray - cropped image
    """
    return img[border_y:-border_y, border_x:-border_x, :]