Edge enhancement - sum of the absolute image gradient for all orientations.

gradient_edge_enhancement.py

def gradient_of_image(image):
    """Direction agnostic."""
    grad = np.gradient(image)  # gradients for individual directions
    grad = np.stack(grad, axis=-1)  # from list of arrays to single numpy array
    gradient_image = np.sum(abs(grad), axis=-1)
    return gradient_image