院徽手绘效果图

from PIL import Image
import numpy as np 
a = np.asarray(Image.open(r'C:\Users\Administrator\Pictures\院徽.jpg').convert('L')).astype('float') 
depth = 10.     # (0-100) 
grad = np.gradient(a)    
grad_x, grad_y = grad 
grad_x = grad_x*depth/100. 
grad_y = grad_y*depth/100. 
A = np.sqrt(grad_x**2 + grad_y**2 + 1.) 
uni_x = grad_x/A 
uni_y = grad_y/A 
uni_z = 1./A 
vec_el = np.pi/2.2 
vec_az = np.pi/4.  
dx = np.cos(vec_el)*np.cos(vec_az)  
dy = np.cos(vec_el)*np.sin(vec_az) 
dz = np.sin(vec_el) 
b = 255*(dx*uni_x + dy*uni_y + dz*uni_z)  
b = b.clip(0,255) 
im = Image.fromarray(b.astype('uint8'))
im.save(r'C:\Users\Administrator\Pictures\院徽手绘.jpg')

绘图前：

效果图：