How to draw a line in OpenCV Python

You can draw a line in OpenCV Python by following the given steps. I highly recommend you get the “Computer Vision: Models, Learning, and Inference Book” to learn Computer Vision.

Step 1

Import the OpenCV library. If OpenCV is not installed in your system then first install it using This Method.

import cv2 
#cv2 is used for OpenCV library

Step 2

Now read the image from the location. In my case “C:\\AiHints” is the location and “AI.jpg” is the name of the image. Change it according to your image location and name.

image = cv2.imread("C:\\AiHints\\AI.jpg")
#imread is use to read an image from a location

Step 3

Now I will draw a line on the image using the following code. In the code, (40,40) is the starting point, and (350,40) is the final point of the line. After that, I will specify a color for the line (0,255,0) that is green color. In the end, 6 is the thickness of the line. You can change any value according to your requirement.

image2 = cv2.line(image,(40,40),(350,40),(0,255,0),6)

Step 4

To display the image in a specified window use ”imshow” function.

cv2.imshow("Green Line on Image",image2)

Step 5

“waitKey(0)” will display a window until any key is pressed. “destroyAllWindows()” will destroy all the windows that we created.

cv2.waitKey(0)
cv2.destroyAllWindows()

Output