Add transparency to rectangles, circles, polgons, text or any shape drawn in OpenCV.

Transparent drawings in OpenCV.py

import cv2

image = cv2.imread('test.jpg')
overlay = image.copy()

x, y, w, h = 10, 10, 10, 10  # Rectangle parameters
cv2.rectangle(overlay, (x, y), (x+w, y+h), (0, 200, 0), -1)  # A filled rectangle

alpha = 0.4  # Transparency factor.

# Following line overlays transparent rectangle over the image
image_new = cv2.addWeighted(overlay, alpha, image, 1 - alpha, 0)

Thanks a lot man

Great!

Thanks alot

thanks

Thanks

Thanks!

Nice work...Thanks!

How can two rectangles have different transparency?

How can two rectangles have different transparency?

@davidgikas,
One way I think that can be done is to just go on doing this same process iteratively.
Add the first rectangle using the above script, and then just create the second rectangle and add to image_new with your desired alpha using cv2.addWeighted.

Thank you, i did this in a for statement and it worked!

Thanks a lot!
is there a more efficient way of doing this? since copying a large image is computationally heavy when I want to draw it many times a second

i think open cv should implement this inside rectangle function as a parameter of transparency

i think open cv should implement this inside rectangle function as a parameter of transparency

Yup. Completely agree. This should be a straightforward thing yet we have to do it in a roundabout way currently.

Thanks :)

Man ! at last i found a simple solution. Lots of thanks. Allah bless you

Cheers!

This method works!

Nice & Thanks

very good very nice!

Appreciated!!

Legend!

You are a hero :)

Thank you so much!