Center text on an image with Python and OpenCV. Had to come up with it myself as no one was spelling this out anywhere (or google couldn't find it)

center_text_on_image.py

#!/usr/bin/env python

import numpy as np
import cv2
from time import sleep

# create blank image - y, x
img = np.zeros((600, 1000, 3), np.uint8)

# setup text
font = cv2.FONT_HERSHEY_SIMPLEX
text = "Hello Joseph!!"

# get boundary of this text
textsize = cv2.getTextSize(text, font, 1, 2)[0]

# get coords based on boundary
textX = (img.shape[1] - textsize[0]) / 2
textY = (img.shape[0] + textsize[1]) / 2

# add text centered on image
cv2.putText(img, text, (textX, textY ), font, 1, (255, 255, 255), 2)

# display image
cv2.imshow('image', img)

# wait so you can see the image
sleep(25)

# cleanup
cv2.destroyAllWindows()

Thanks for the code.
Think textX and textY should use integer division though. At least the version of opencv I'm using requires them to be integers.

Thanks a lot, made my life easier 👍

Thank you so much @xcsrz

In line28, sleep funcion maked python can't disply the image, It shuld be use - cv2.waitKey(0)

Great work. This gist saved me a lot of time.

Nice 👍

Thanks!

Thank you. This helped me out a ton.

Thank you so much!

TypeError: integer argument expected, got float

can you please tell how to solve this?

Thanks for the amazing code! much appreciate it

@haiderasad does that mean you got around your type error? I haven't encountered that but my guess is you need 18-19 to round:

textX = round((img.shape[1] - textsize[0]) / 2)
textY = round((img.shape[0] + textsize[1]) / 2)

Or just do

textX = (img.shape[1] - textsize[0]) // 2
textY = (img.shape[0] + textsize[1]) // 2

Thanks it works great

for future people using this: cast to int and use python_naming_conventions

The method

 # get coords based on boundary
textX = (img.shape[1] - textsize[0]) / 2
textY = (img.shape[0] + textsize[1]) / 2

can lead to values with decimal placed and a decimal of a pixel is not yet defined. Suggest to round them or //2 as the guys said!

Besides that, great and simple implementation of this tool!

good

C++ users do this

    int textX = (resizedSize.x - size.width) / 2;
    int textY = (resizedSize.y + size.height) / 2;

https://gist.github.com/Erol444/962bf3d2bd5813d1475d03d154c9966b <- A script that adds a bit more options, like printing text at specific location on frame (topLeft, middle, bottomRight...) and text padding.