原图如下:
(原图：life1.jpg)
代码如下：
from PIL import Image
import numpy as np
vec_el = np.pi/2.2
vec_az = np.pi/4.
depth = 40.
im = Image.open('C:\Users\邓若言\Desktop\life1.jpg').convert('L')
a = np.asarray(im).astype('float')
grad = np.gradient(a)
grad_x, grad_y = grad
grad_x = grad_x *depth/100.
grad_y = grad_y *depth/100.
dx = np.cos(vec_el)*np.cos(vec_az)
dy = np.cos(vec_el)*np.sin(vec_az)
dz = np.sin(vec_el)
A = np.sqrt(grad_x**2 + grad_y**2 + 1.)
uni_x = grad_x/A
uni_y = grad_y/A
uni_z = 1./A
a2 = 255*(dx*uni_x + dy*uni_y +dz *uni_z)
a2 = a2.clip(0,225)
im2 = Image.fromarray(a2.astype('uint8'))
im2.save('C:\Users\邓若言\Desktop\life11.jpg')
效果：
