# How to best identify QR markers?
**URL:** https://forum.opencv.org/t/how-to-best-identify-qr-markers/2817
**Category:** C++
**Tags:** homography
**Created:** [April 17, 2021, 3:22pm UTC](https://forum.opencv.org/t/how-to-best-identify-qr-markers/2817 "2021-04-17T15:22:46Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@hamzaabd](https://forum.opencv.org/u/hamzaabd)
#### Post date: [April 17, 2021, 3:22pm UTC](https://forum.opencv.org/t/how-to-best-identify-qr-markers/2817/1 "2021-04-17T15:22:46Z")
I have made a code to identify QR markers but I want to make sure that it is the correct method. My current method is to make the QR marker canonized (make the QR marker fit a square ) and then resize it to an 8 by 8 image and then see for each pixel if it is 1 or 0 and store that in an array. Then I match it with an array made from a list of the original markers. This works but some of the QR markers are not identified which is why I wanna see if there are other methods. Maybe I should look at the features of the QR markers to find a match instead?
---
### Author:  [@berak](https://forum.opencv.org/u/berak)
#### Post date: [April 17, 2021, 4:00pm UTC](https://forum.opencv.org/t/how-to-best-identify-qr-markers/2817/2 "2021-04-17T16:00:24Z")
sounds like you’re reinventing the wheel.
why not use one of the existing qr schemes in opencv, e.g. [here](https://docs.opencv.org/master/de/dc3/classcv_1_1QRCodeDetector.html) or [here](https://docs.opencv.org/master/dd/d63/group __wechat__ qrcode.html) ?
---
### Author:  [@crackwitz](https://forum.opencv.org/u/crackwitz)
#### Post date: [April 18, 2021, 8:57am UTC](https://forum.opencv.org/t/how-to-best-identify-qr-markers/2817/3 "2021-04-18T08:57:22Z")
there’s a difference between “QR codes” and “augmented reality markers”.
QR codes convey data, and nothing else. it can be a lot of data, kilobytes even. they’re designed so that a machine can robustly recover all the information.
AR markers have a simple identity (a dozen bits or so), and they allow a camera to determine its precise location relative to the marker.
QR codes aren’t designed for localization, AR markers aren’t designed to hold a lot of data.
 