import numpy as np
import pylab as plt
from skimage.io import imread


n = imread('image.jpg').mean(2)
z = np.zeros((500,500))

while True:
    for i, x in enumerate(np.linspace(-1,1,500)):
        for j, y in enumerate(np.linspace(-1,1,500)):
            z[i,j] += 0.01 * (x**2 + y**2 - n[i,j])