Driver License scanning - Barcode scanning for PDF417 is no longer working for some states

[kkamaraj]

Hi,
We are using Google Mobile vision library in our app to scan PDF417 scanning for driver licenses. It used to work for most of the states which are adhere to AAMVA standard. Even if the parser failed to decode to non-compliant with AAMVA standard we used to see that scanning was working fine. However recently we received issues from production app saying some the states licenses scanning stops working.

When I verified my NJ licenses it used to work, however one of my colleagues NJ licenses was not scanning using neither our app nor the visionSamples for barcode scanning. Also we got the image for LA state license which is also failed to scan as well. I will send the licenses as PM upon request as this real DL and I do not want attach it on public forum.

My question, are you aware of any issue on barcode scanning lately? I could able to provide some real licenses to repro the issue on your end upon request. Let me know if you need more details or have any questions.

[pchx-zz]

The PDF417 reader and the AAMVA parser have not changed in any way since the Play Services 10.0 release (November 2016). If you are only seeing a regression now, then it's probably not related to the Barcode API.

[kkamaraj]

@pchx Thanks for the response. The issue I am facing is different. Looks like NJ state license barcode type is changed (There is a visible difference in rendered barcode). I used the Google Vision sample app and camera is not able to detect the barcode itself. If needed I could send you the DL license in a private message, otherwise let me know what sort of logs you want to debug the issue from your end.

[kkamaraj]

@pchx I have attached the LA license which is not scanning. The behavior is same for NJ license as well. Please let me know if you have any questions.

[pchx-zz]

I will take a look, but in the meantime I strongly suggest that you remove that image since it is readable (by means other than our Barcode API) and appears to contain some personal information. Sorry, I couldn't find any means to directly contact you.

[pchx-zz]

The example you provided a valid PDF417 barcode, but you can see gaps in what should be solid black regions in the upper half of the code. This seems to be enough damage that our reader can't decode the image.

[kkamaraj]

@pchx I presume this might be the reason for the reader fail to decode image for NJ state license as well. One of my colleague recently renewed his NJ state license and scanning stopped working with the new one. Old one is still working though. I have the scan copy of the DL if needed I could send you that as well. I can be reached at karthik.kamaraj@gmail.com. I could share the DL directly to you. Are you saying the generated barcode for these non working states is wrong?

[pchx-zz]

They're (probably) perfectly valid barcodes, but when printed at low quality it can be hard to read them except under perfect conditions.

[kkamaraj]

@pchx I understand that image quality might be the reason, however I used the real NJ license and the scanning was not working. We have actually received the issue from production as some of the state licenses were not scanning. Do you aware of any decoding issue with some of the states?

[pchx-zz]

Like I said, my guess (without seeing these licenses) is that they're perfectly valid barcodes that were printed at low quality by the state DMV or otherwise damaged. The PDF417 reader in our Barcode API does not handle these well.

[kkamaraj]

WhatsApp Video 2017-08-07 at 2.03.26 PM.mp4.zip

@pchx I understand that the quality of image might be the reason why the decoder fails to process the image. I have attached the video from my QA engineer who used his latest NJ license to scan using the Barcode API sample app from Github. He used both his latest license and his old expired license. It is evident that the old license was working and the newly issued one is not. I am not sure what might be causing the scanning failure and need your help to look into the issue.

[pchx-zz]

It's hard to tell from the video, but that card does not appear to have a valid PDF417 stop pattern on its right side.

[kkamaraj]

@pchx I see your point. This looks more like an error in printing the barcode. If possible could you let me know what circumstances could make the image decoding to fail?

1. Invalid PDF417 barcode pattern
2. Poor resolution
3. Anything else?
   Also even if the image decode works fine the parser might fail if the decoded string do not follow the AAMVA standard. Am I Correct?

[pchx-zz]

Right.