OT: QR (datamatrix-TEXT) Q ?

[Jethro_uk]

Just wondered if there might be any QR code experts around.

Have a document with a QR code on it. All my QR scanner apps happily decode it, and tell me it's "Data Matrix" and type "TEXT".

So far, so expected.

However, when I try to *generate* the sodding thing, with any number of free online apps, giving them the data extracted seems to generate a completely different QR code ?????

Well, not completely different, but certainly not identical.

The original QR code seems to be 40x40, and looks like it's somehow 4- quartered.

The closest I have got was this site

which allows tweaking of a lot of parameters. But even then, selecting TEXT, 40x40 the resulting QR code doesn't look the same.

HOWEVER - it still scans and delivers the exact data extracted from the original QR code.

Can anyone explain this, and (more importantly) is this a difference which makes no difference ?

Does anyone know of a facility to read in and reproduce QR codes for inclusion in documents etc ?

Thanks guys.

[Andy Burns]

Have you tried

Can you share it anywhere?

[Bob Eager]

There are a lot of variables that affect the final code. As you have discovered, once is the actual dimensions of the code (e.g. 40x40).

Another is the error correction level (redundant information). If you set this high, a lot of the code can be onbliterated and it will still work (this can be used to embed a logo in the middle!). There are other things too.

This tells you a bit:

[Dave W]

A Data Matrix is not the same as a QR code, and some indeed look like they've got four quarters. QR codes all have big registration squares in three of the corners. The data matrix has solid black on two adjacent edges and dotted black on the other two. I don't know any online generators, but the following site can decode many types of code:

[Jethro_uk]

Yup - that happily decodes it, and identifies it as Data matrix,"TEXT"

Sadly not. It's used by DWP on the PIP form. It's NI number, claimants postcode, a postcode elsewhere, and a few numbers.

[Jethro_uk]

I'll have a gander. I suspect it's some level of ECC. But nothing in the online tools seems to be able to tell me what it is. Which seems to then match the symmetry of none of the online tools allowing me to set the ECC :)

[Jethro_uk]

That was the site I used.

I also used a barcode/QRCode reader app on my phone, and that was able to tell me it was Data Matrix/TEXT.

[Jethro_uk]

CHeers for the replies. FWIW I have generated a 40x40 data matrix which my phone app decodes as being identical to the original - despite the visual differences.

I hope the end processing hardware thinks the same :)

[Andy Burns]

I did mean to generate it

OK, That let me search for examples of people who /have/ published copies of their PIP form online (carefully blurring the address text but not the barcode!)

To confirm what others have said, that's not a QR code, try this instead

[Jethro_uk]

I would be very worried if the exist. The *barcode* contains the claimants NI number and postcode.

OK ..

[Andy Burns]

One example I found was not particularly high res, by the time you'd cropped and deformed the barcode back to square, there would probably be insufficient resolution to extract the text, even with error-correction.

[Chris Green]

I realise why you're saying this but NI number and postcode are hardly well guarded information in general. Just about every payslip will have them on and, while one shouldn't let these go astray, I'm sure there are loads out there just floating about. It also means that every employer has this data and I bet it's not held as securely as it should be.

Anything that relies on just postcode and NI number to confirm someone's identity is going to be very easily fooled.

[Jethro_uk]

Oh quite agreed.

It's just *this* NI/Postcode would identify *me*, which is not something I'm particularly up for at this moment in time.

Anyway, I have used the site

creator.html to generate a 40x40 TEXT encoded matrix. I manipulated the image to match the 17mm image on the form, and printed out a copy.

When scanned with my app, it reads exactly the same as the original, so let's see.

I suspect the code is nothing to do with identity, and simply a crude way of automating the collation and organisation of returned forms. My desire to recreate the code is to allow me to generate the entire submission electronically. That way they can "lose" as many copies as they like with no inconvenience to myself.

Through many years experience, I tend to have my cynic meter on overload when dealing with officialdom. Generally a little forethought and planning can save a whole lot of ballache further down the line.

[Jethro_uk]

just looking at the site again, and I wonder what playing with

might do.