Is it possible to add watermark to QR code generated by google charts api

Question

Is it possible to add watermark to QR code generated by google charts api using jquery or cakephp.

I appreciate any help.

Thanks.

Answer 1

I wouldn't watermark a QR code. Instead, I'd probably watermark the data I was encoding in the QR code in some way.

For example, if you're encoding a URL, could you, for example, change the URL from "http://example.com/foo" to "http://example.com/foo?watermark-referrer=www-yourdomain-com-whatever"? Then there's still an indication that the QR code is yours, but you don't have to risk breaking the QR image itself.

Answer 2

I guess the only way to do that is saving the image generated by google charts on your server, and then add the watermark vi GD or imagemagick.

Answer 3

A jQuery option is to just place a watermark image on top of the one that Google Charts makes, but the original will still be available.

A PHP option is generate the QR image via a curl request, read the bitmap data in, muck with it via GD or ImageMagick, then save it somewhere and display it.

The watermark may interfere with a scanning algorithm, though, especially when read with a bad camera.

Answer 4

I think you should test the QR code with watermark, because there is a big chance that lots of reader won't recognize.