QR code orientation

[zjudmd1015]

Hi Author,
Thanks for the amazing work. Is there a way I can get info of the orientation of QR code?

Thanks!

[esclear]

This would be made possible by #39 and by checking the relative position of the first two points in the polygon.

[marco-fuchs]

Hi @esclear
I have made the changes from PR 39. Can you may give me an additional hint on how I can now determine the orientation (angle) of the "top-point" from the the qr-code.
Picture of my problem:
https://stackoverflow.com/questions/52678376/how-to-detect-top-edge-of-qr-code-in-python-and-pyzbar/52681707

Is this even easy possible?
Thanks in advance!

[esclear]

Certainly.
Assuming that qrcode is the object you get from pyzbar, it is very simple:

from math import atan2, pi

def get_angle(qrcode):
    poly = qrcode.polygon
    angle = atan2(poly[1].y - poly[0].y, poly[1].x - poly[0].x)
    return angle - pi/2

The result is the angle (in radians) of the qr code with respect to its normal upright position.

[marco-fuchs]

This helps me a lot - thank you!