How to Turn a Photo to Sketch Using Python

In this tutorial, we will be looking at how to convert a photo to sketch using Python. To do this we will use OpenCV library as our image manipulation library.

To begin run the command below on your terminal to install opencv.

pip install opencv-python

After installing OpenCV , create a folder called sketch and create a file called main.py . Insert the photo you want to convert into the folder.

Now let’s code our program, inside the main.py import opencv as shown below.

import cv2

Now let’s load our image.

img = cv2.imread('sample.jpg')

Next convert the loaded image into a gray scale

gray_img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

Invert the grayscale image to create a negative image.

inverted_gray_img = 255 - gray_img

Here we will apply a gaussian blur to the inverted grayscale image

blurred_img = cv2.GaussianBlur(inverted_gray_img, (21, 21), 0)

Now let’s blend the inverted image and the blurred image.

def dodgeV2(image, mask):
    return cv2.divide(image, 255-mask, scale=256)

sketch_img = dodgeV2(gray_img, blurred_img)

cv2.imshow('Original Image', img)
cv2.imshow('Pencil Sketch', sketch_img)
cv2.waitKey(0)
cv2.destroyAllWindows()

Now run the code as shown below.

python3 main.py

After running the command above, here is our sketch image.

Here is the whole code.

import cv2


img = cv2.imread('sample.jpg')

gray_img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

inverted_gray_img = 255 - gray_img

blurred_img = cv2.GaussianBlur(inverted_gray_img, (21, 21), 0)

def dodgeV2(image, mask):
    return cv2.divide(image, 255-mask, scale=256)

sketch_img = dodgeV2(gray_img, blurred_img

cv2.imshow('Original Image', img)
cv2.imshow('Pencil Sketch', sketch_img)
cv2.waitKey(0)
cv2.destroyAllWindows()

There you have it, thanks for reading. Happy Coding