QR Code Reader - Encoding/Decoding Large Data Sets

[Brooks_LV]

Hi,

I am writing an application to decode large data sets (as much as 4,500 characters) in a QR code.  I have successfully been able to decode a QR code with 1,695 characters but when I try to decode a QR code with 1,710 characters (or more) it fails.  I am using the IMAQ Read QR Code VI from the Vision Development Module.  There is no error message generated from the VI, it simply ouputs an empty data string. The input parameters to the IMAQ Read QR Code VI are the same as when I read the QR code with 1,695 characters.  The Matrix Size parameter is set to "Auto Detect" to account for the possibility of a larger matrix size. QR code parameters used when creating the QR code are:

Cell size = 3x3 pixels

Error Correction = M

Data Type = Numeric

A version 36 (161x161) QR code with M level error correction should be able to contain 4,588 characters.  I would like to be able to decode a QR code of this size.  Is the "IMAQ Read QR Code" VI limited to only being able to decode some of the smaller QR codes?  Any thoughts as to why I cannot decode larger QR codes?  I am attaching the QR code that was not successfully decoded.

Thanks,

Brooks_LV

[Tanner!]

Brooks_LV,

Unfortunately that VI calls in to a DLL, so it's going to make troubleshooting difficult. I'll ask the engineers that work on this if they have any ideas and post if they have anything promising.

[PhillipBrooks]

I tested your image against the on-line zxing decoder.

https://zxing.org/w/decode.jspx

I referenced your uploaded image to the NI forums.

https://zxing.org/w/decode?u=http%3A%2F%2Fforums.ni.com%2Fni%2Fattachments%2Fni%2F170%2F927922%2F1%2...

The returned string is 1710 chars long. I have an old version of the zxing .net component that I tried to use to process your image, but the image type could not be determined.

[PhillipBrooks]

The zxing library has numerous options for decoding.

After experimenting a bit, I found that your image can be decoded using the zxing.net library by with the decode hint pure_barcode.

Typically, the image would be from a camera so I never tried this option before.

[Brooks_LV]

Thanks Phillip!  I will use this as a workaround if NI is not able to come back with something that will work with their VI.  I appreciate your time on this.

Brooks_LV

[PhillipBrooks]

Have you tried processing an acquired image of your QR code from a camera instead of the "perfect" image file?

Maybe LabVIEW has a similar problem as the zxing lib. 

[Brooks_LV]

Hi Phillip,

No, I have not tried acquiring an image from a camera.  My application will only be decoding "perfect" images.

Thanks,

Brooks_LV

[Brooks_LV]

Hi Tanner,

Any word from R&D on this?

Thanks,

Brooks_LV

[Tanner!]

I'm still in the process of escalating this, and will let you know as soon as I know something.

[Brooks_LV]

Hi Tanner,

It's been a while and I haven't heard anything from you.  What's the status?

Thanks,

Brooks