Issue 538 in zxing: Barcode scanner does not recognize CODABAR format barcode used for library card
zx...@googlecode.com
Owner: ----
New issue 538 by dfarinet: Barcode scanner does not recognize CODABAR
format barcode used for library card
http://code.google.com/p/zxing/issues/detail?id=538
What steps will reproduce the problem?
1. Tried to scan the barcode directly on my library card - no recognition
2. Using online free barcode generator, recreated my library barcode in a
larger image and tried to scan that on computer screen- still no
recognition of the Codabar barcode
3. tried printing the barcode image in a larger size and scan with Barcode
Scanner, still no recognition of Codabar barcode
What is the expected output? What do you see instead?
Just recognize the codabar barcode so I can store it in a card bank
What version of the product are you using? On what operating system?
latest version v3.4, HTC Incredible, Android version Froyo 2.2
Please provide any additional information below.
example of Codabar barcode attached
Attachments:
radTEST.png 1016 bytes
zx...@googlecode.com
Status: NotABug
Comment #1 on issue 538 by sro...@gmail.com: Barcode scanner does not
recognize CODABAR format barcode used for library card
http://code.google.com/p/zxing/issues/detail?id=538
Codabar is not enabled in Android mostly because it is almost never used
and might hurt performance slightly. I don't know if there's plan to change
that, though it's simple to make a build that also searches for Codabar if
you like, for your own use.
zx...@googlecode.com
Comment #2 on issue 538 by dpavlin: Barcode scanner does not recognize
http://code.google.com/p/zxing/issues/detail?id=538
I needed to do same thing today, so I'm attaching diff which adds CODABAR
to Android.
Hopefully this will save an hour-or-two of poking around to someone who
stumbles upon this issue as I did :-)
Attachments:
zxing-android-codabar-enable.diff 1.2 KB
zx...@googlecode.com
Comment #3 on issue 538 by sro...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
Yup that's it. How well does it work? Then only reason it could be harmful
is if it causes false positive recognition in other scans. Let me know how
it goes for you.
Bas Vijfwinkel
The major problem was the large number of false-positives with other
barcodes.
The decoding itself works pretty fine but there are hardly any limits
or constraints regarding this type.
There is no minimum length (1 character length messages are allowed),
there is no checksum and there is no minimum length for the leading
and trailing whitespace.
All these missing constraints add up to a large number of false
positives for other barcode types and therefore it was decided not to
enable the CODABAR type by default.
If you are planning on using it, just enable it but if you are
planning on scanning various types of barcodes, I would suggest you
add the following 2 constaints :
- minimum leading and trailing whitespace
- minimum number of characters (e.g. minimum of 8 )
Also if you know more about the specific application of the CODABAR
barcodes, check if a checksum character is added
(but as said earlier, this is not part of the CODABAR standard which
was introduced when I was still crwaling around in diapers). =)
Good luck!
Bas Vijfwinkel
On Oct 13, 7:25 pm, zx...@googlecode.com wrote:
> Comment #3 on issue 538 by sro...@gmail.com: Barcode scanner does not
zx...@googlecode.com
Comment #4 on issue 538 by dpavlin: Barcode scanner does not recognize
http://code.google.com/p/zxing/issues/detail?id=538
I'm using zxing on my phone with CODABAR enabled for few weeks now and
haven't seen false positive yet, but I'm mostly testing with CODABAR
barcodes which we have on books in our library.
zx...@googlecode.com
Comment #5 on issue 538 by harryliu...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
I'm using changes in comment 2, it works perfectly, don't even need to
change core code
zx...@googlecode.com
Comment #6 on issue 538 by harryliu...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
I'm using changes in comment 2 by dpavlin, it works perfectly, don't even
need to change core code, thanks.
zx...@googlecode.com
Comment #7 on issue 538 by lmcke...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
Hi, I work for the Contra Costa County Library and we are developing the
ability to check books out using a smart phone. In order to do this, the
phone needs to be able to read our 14 digit codabar barcodes. from reading
the comments above, it looks like the code has already been developed but
may not be included in the current release. Can I ask someone if that is
correct and how I might get you to release the code?
I've see other comments about codabar being problematic because it doesn't
require a check digit. I don't really know much about the standard, but the
barcodes used by most library systems use a 14 digit number with a check
digit. This site gives the information on how the check digit is used for
most library systems: http://www.makebarcode.com/specs/codabar.html
Bas Vijfwinkel
The check digit is not part of the official codabar standard and
depending on the
application/vendor various ways of checking the validity of the
codabar barcode have been added.
I don't know what codabar is used for besides libraries so it might be
a good suggestion to add it.
On May 25, 4:53 pm, zx...@googlecode.com wrote:
> Comment #7 on issue 538 by lmcke...@gmail.com: Barcode scanner does not
zx...@googlecode.com
Comment #8 on issue 538 by sro...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
It is included, but not turned on, since it will result in too many false
positives when scanning other formats. You can write an app that asks it to
scan for only ITF, using Intents.
zx...@googlecode.com
Comment #9 on issue 538 by athom...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
Could a setting be added for users to turn it on, instead of just telling
them to write their own apps?
zx...@googlecode.com
Comment #10 on issue 538 by geocolum...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
is a challenge. The routine in the Java (Android) fork did not work well,
so it was left turned off by default apparently. Also (probably because it
didn't work well), it was not ported over to the Objective-C and CPP
versions. So really, there is no current way to read codabar with ZXing on
iPhone - only on Android. I've tried the routine on Android and it takes a
lot of fiddling with the camera, lighting, position before it finally gets
a read. I too need to read codabar on iPhone, so some custom programming is
going to be required. Note - if you are willing to pay a licensing fee, Red
Laser's SDK claims to read codabar...
zx...@googlecode.com
Comment #11 on issue 538 by srowen: Barcode scanner does not recognize
The Java version works quite well -- same as any other 1D format. It was
not enabled since Codabar does not have a checksum, and so it's too easy to
read a false positive Codabar barcode. That, and it's not used much.
It wasn't ported just because nobody ported it. RedLaser is a partial port
of zxing, note.
zx...@googlecode.com
Comment #12 on issue 538 by Daniel.Z...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
Android. The format was "CODABAR". Is this now enabled by default?
zx...@googlecode.com
Comment #13 on issue 538 by Daniel.Z...@gmail.com: Barcode scanner does not
http://code.google.com/p/zxing/issues/detail?id=538
http://code.google.com/p/zxing/source/detail?r=2158&path=/trunk/android/src/com/google/zxing/client/android/DecodeFormatManager.java
Jeff Brower
We require Codabar on Android, iOS and Windows phones but it seems to be disabled on iOS by zxing. Is the Apple phone somehow inferior to 1960's technology for scanning?
Is there a way to turn on/off codes that we want to use/ignore - perhaps even to reduce application size - that we could use to turn it back on?
We want to maintain a single unified code base for all 3 phones and we thought we found it with zxing, but not being able to read across all devices seems to be a non-starter for zxing - is there another way to use zxing to accomplish reading both QR and Codabar on all 3 phones?
Bas Vijfwinkel
> We want to maintain a single unified code base for all 3 phones and we thought we found it with zxing, but not being able to read across all devices seems to be a non-starter for zxing - is there another way to use zxing to accomplish reading both QR and Codabar on all 3 phones?
I added Codabar some years ago but during testing we also found out it generates a lot of false positives because it is very similar to other 1D barcodes and does not have any minimum length or checksums build in.
That is why it was disabled, besides the fact that it is not as popular as other types.
If you maintain your own codebase you might consider forking the project and just building it yourself with the codabar settings turned on.
You could also try to send a request to have to iOS version updated so that it works in the same way as Android. Those settings should be similar.