not able to read datamatrix

Question

not able to read datamatrix

bsdis opened this issue 6 years ago · 6 comments

Does anyone have an idea why I cannot read this QR code using libdmtx software? I dont think the quality of the image is that bad... https://i.ibb.co/FnQkcSL/platedmtrx.png

Answer 1 · 2019-06-05T06:22:37.000Z

First it is a Datamatrix not QR code. The problem is most probably the quality, try to binarize the image and than pass it to the library. Also you need to have at least one module empty space on each side.

Answer 2 · 2019-06-09T15:51:34.000Z

Hi, even this binarized image is not being decoded:
https://i.ibb.co/Gk7sFZ1/Screen-Shot-2019-06-09-at-17-44-53.png
Why?

Answer 3 · 2019-06-09T22:54:04.000Z

Hi, even this binarized image is not being decoded: https://i.ibb.co/Gk7sFZ1/Screen-Shot-2019-06-09-at-17-44-53.png Why?

Does your goal is to read the content of exactly this matrix (once), and then forget about it, or do you want to build some algorythm to read many more matrixes like that? In case of the former one, I can decode it for you (it's not a big matrix and I can do what I described below). In case of the latter one, it's a bit complicated.. Well, the main reason of impossibility to decode this matrix, imo, is that it is very "dirty" (some cells have different width/height, some of them are even shifted a bit). So, talking honestly, that make it to be a not-a-matrix-at-all for decoding algorythm, but something-that-looks-like-matrix to you. If you'll make a real matrix with "valid" cells, colored with a pattern of your given "matrix", I bet decoder will read it.

Answer 4 · 2019-06-09T23:08:33.000Z

Well, it is also few things, that can be the reason of failing to decode. One of them, say, is a wrong "checksum".

Answer 5 · 2019-06-09T23:51:15.000Z

Btw, talking about terminology.
"Binarization" is not just making it b/w. It is more like "making it easier to decoder to represent cells like binary code". And there, well, should be cells (square ones), although decoder allows some deviation, but there is no magic exists in the world, so decoder can't perform the miracle.
I've properly binarized your initial (soldered) matrix, and got the "8205279" as decoding result:

Although, your second image looks like the broken one (maybe, it is either randomly picked "pseudocells", or some "pseudocells" was colored by mistake (or even some of them are missing)).

Answer 6 · 2020-01-30T10:02:51.000Z

I don`t know where place this
https://github.com/dmtx/libdmtx/wiki/Repair-Error

I found error. May be it can fix this