#245 datamatrix size 144x144 barcode is not readable using the zxing online decoder

[Andre Maute]

Hi zint team,

I downloaded the official windows binary for zint 2.10
and used the cmd frontend in order to generate a DataMatrix barcode image.

The image is attached and it can't be read with the ZXing Online Decoder.
So I wonder if this one is a valid readable barcode.
This happens only for the size 144x144.

I use wine under Fedora 33, because I'm working under linux.

wine zint.exe --square --gs1 --gs1parens -b 71 -d "(20)01" -o dm.png --vers=24

The ZXing Online Decoder

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

gives

Raw text: 17488280
Raw bytes: (Not applicable)
Barcode format: UPC_E
Parsed Result Type: PRODUCT
Parsed Result: 17488280

Regards Andre

[Git Lost]

Hi Andre, yes, ZXing (and ZXing-C++) can't deal with DataMatrix images with no quiet zone unless the isPure flag is set. If you do

zint --square --gs1 --gs1parens -b 71 -d "(20)01" -o dm.png --vers=24 --whitesp=2 --vwhitesp=2

then it should work (seem to need 2 though the quiet zone should only need to be 1). My diagnostic branch of ZXing-C++ has a workaround for this (calls DetectPure() if DetectNew() fails).

Regards, Martin

[Andre Maute]

Hi Martin,

so you may close this ticket. Though I wonder why only the size 144x144 is affected?

Regards Andre

[Harald Oehlmann]

Hi André, Hi Martin,

I can confirm that many decoders have issues with the short quiet zone of Data Matrix.
QR-Code has 3 modules quiet zone.

It is a great analysis that it only concerns 144x144.
I propose to ask the question on the zxing side.

Thank you,
Harald

[Git Lost]

Andre - yes, you're right re 144x144 only, didn't check other versions with ZXing, for ZXing-C++ it affects all versions I think as it uses the new implementation DetectNew().

Hi Harald, yes, the same workaround would probably work for ZXing but a proper fix would be better, thanks