How can you read QR Codes in PHP?

Question

Is there a plain PHP implementation for decoding QR codes?

I have a faux-smartphone. One of those phones that parades as a smartphone but that I can't download any apps for, and I want to create an email service to where I can take a picture of a QR code, MMS it to this email, and the email returns what the QR code contains.

However, the only libraries I've been able to find are in Python (and probably C++), neither of which I can access on my limited hosting environment.

Is there a way to read QR codes using only PHP?

Answer 1

There appears to be an API in google charts you can pass the image along to: http://code.google.com/apis/chart/docs/gallery/qr_codes.html - but that assumes you have already detected/extracted the QR code from the rest of the image.

Answer 2

I'm not aware of any pure php decoder. Decoding images like this is pretty processor intensive and doing it in a purely interpreted language is challenging.

zxing (http://code.google.com/p/zxing/) provides a decoder implementation in both Java and C++. In theory, it should be possible to link the C++ library as a php extension, though I don't know anything of the mechanics of that. I've done it for Ruby ...

Moreover, zxing does have an online decoder at http://zxing.org/w/decode.jspx. My thinking is that from PHP you can take the image and post it to the webservice and retrieve the decoded data. I don't know the mechanics of making remote web service calls from PHP and how different hosting environments might limit that, though, but it seems reasonable?