Python implementation of hand drawing effect example sharing

First, let's take a look at the original picture:

Then we take a look at the renderings:

Through analysis, we can easily find the following characteristics:

• The main color is black, white and gray

• Heavier border lines

• The same or similar colors tend to be white

• Slight light source effect

The libraries that need to be used are:

• numpy

• PIL

Code:

importnumpyasnp
fromPILimportImage

baseImg=Image.open("./img/myimg2.jpg").convert("L")#Place the original picture you want to hand-paint here
a=np.array(baseImg).astype("float")

depth=8.
grad=np.gradient(a)#Take the gradient value of the image gray

grad_x,grad_y=grad#Simulate image gradient value
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#Light source top angle, radian value
vec_az=np.pi/4.#The official’s azimuth angle, radian value
dx=np.cos(vec_el)*np.cos(vec_az)#The influence of the light source on the x-axis
dy=np.sin(vec_el)*np.sin(vec_az)#The influence of light source on y-axis
dz=np.sin(vec_el)#The influence of the light source on the z axis

b=255*(dx*uni_x+dy*uni_y+dz*uni_z)#Light source normalization
b=b.clip(0,255)#limit

img=Image.fromarray(b.astype("uint8"))#Reconstructed image
img.save("./toImg/myImage1.jpg")#Save image

Example extension:

from PIL import Image
import numpy as np

# In order to facilitate the import of files, you can use relative paths to place the files and programs in the same folder

vec_el=np.pi/2.2
vec_az=np.pi/4.
depth=10.
im=Image.open("HIT2.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(0,255)
im2=Image.fromarray(a2.astype('uint8'))
im2.save('hit2-SH.jpg')

This is the end of this article about the sharing of hand drawing effects in Python. For more related Python hand drawing effects, please search for ZaLou.Cn's previous articles or continue to browse related articles below. Hope you will support ZaLou more in the future. .Cn!