Make beautiful pencil sketches using OpenCV in 9 lines of code
2 min read
For this simple project we will use OpenCV in Python.
It is a library using which we can develop real-time computer vision applications. It mainly focuses on image processing, video capture and analysis including features like face detection and object detection.
But before that....
A bit of backstory
When I was in 7th grade (3 years ago), I used to play with this photo editing software called " GIMP ". (short for GNU Image Manipulation Software)
Using a couple of clever techniques, I would make sketches out of images like what you saw in the thumbnail.
Let's see how this process works.
- You take an image
- Convert it to grayscale
- Invert the grayscaled image
- Blur the inverted image
- Subtract the grayscaled image from the blurred inverted image
et voilà !
I figured that I could automate this process using OpenCV, let see the code and how it works.
import cv2 # Importing the OpenCV libarary img = cv2.imread('image.jpg') #Reading the image img_gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) #Converting the image to grayscale img_invert = cv2.bitwise_not(img_gray) #Inverting the grayscaled image img_smoothing = cv2.GaussianBlur(img_invert, (21, 21),sigmaX=0, sigmaY=0) #Blurring the inverted image def dodge(x, y): return cv2.divide(x, 255 - y, scale=256) final_img = dodge(img_gray, img_smoothing) #Subtracting the blurred iamge from the orignal image cv2.imwrite('img.jpg', final_img) #Writing the final output to a a file
Just like that in 9 lines of code, you can easily create skteches using OpenCV and Python!
Here's the Github repository with this code .
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