Barcode Issues (Specifically DataMatrix's getting read incorrectly)

Steps causing the bug to occur

  1. Placed large datamatrix in front of C910 webcam
  2. Partially occlude datamatrix (or sometimes just leave it as it is)
  3. Output from datamatrix node sometimes jumps back and forth between numbers and proper reading of text.

Other notes

  • Vuo version: 1.2.6-alpha2
  • macOS version: macOS 10.12
  • How severely does this bug affect you? It’s annoying but I can work around it.

We had a few instances of the Barcode node incorrectly reading a Datamatrix and ended up displaying numbers momentarily rather than the text that it should have read. Sometimes it was briefly, sometimes it flipped back and forth between numbers and a proper reading and other times numbers were visible for a few seconds before it was read correctly and displayed text. We also had a couple of instances where it displayed numbers when it decided a wood grain was a barcode (The card holder we have the camera mounted to was made of wood). This got me thinking that because the barcode reader can read different types of barcodes perhaps before it read the datamatrix as a datamatrix that it may have incorrectly identified it as a different type of barcode and spit out the results before correctly detecting it as a datamatrix. I think a simple fix might be to add a drop down list of the type of barcode we would like the node to look for. This could prevent incorrect identifications.

I managed to snap a few pictures of two incorrect readings of the same datamatrix (one with a partially occluded datamatrix) along with the correct reading. Because it contains student information I can’t post it here but could privately send them to you.

Yeah, your idea that maybe your barcode is being identified as the wrong kind of barcode sounds plausible. And adding the option to select the type of barcode (or to have it auto-detect, as it does now) sounds like a good fix, as well as a possible performance speedup.

Hi Jaymie, I’m just looking into wether any changes to the barcode node, as requested above, might be making it into the next update? While I’m still months away from our next ceremony where I’ll being using it again, I just wanted to avoid the same issues I ran into last summer with it misreading the data under certain conditions. Thanks.

Yep, we’ve made some improvements, including an option to specify the type of barcode. If you’d like to send some of those student barcodes privately (, we can see if that fixes your problem. And/or I can let you know if we publish an alpha/beta release of Vuo 1.3 so you can test yourself.

@cwilms-loyalist, if you specify the type of barcode (the new option in Vuo 1.2.7), does the node read your DataMatrix barcodes correctly?

BTW Jaymie I have been heavily testing the barcode reader this week and the new update has been working flawlessly! As you predicted it seems quicker as well, probably because it’s not having to figure out which type of barcode it’s looking at before it spits out the readout. Amazing work!

Wonderful! Thanks for testing, @cwilms-loyalist!