Some insight into crash in EAN13 barcode generator

[Daniel James-2]

Hi all,

I was excited to see the barcode generator plugin in Inkscape 0.46,
finally I can make my own EAN-13 barcodes for book jacket designs :-)

I ran into this bug though, while testing 64 Studio 3.0 beta 3, which is
Ubuntu Hardy LTS based. The Inkscape package is the same binary as in Hardy.

https://bugs.launchpad.net/ubuntu/+source/inkscape/+bug/334073

I think I found the cause, a bug in the plugin. If you select Barcode
Type as EAN13 and enter 13 digits into the Barcode Data field, which is
correct according to:

http://en.wikipedia.org/wiki/European_Article_Number

you get the error as shown in the Launchpad ticket. If you enter any
number of digits other than 12 or 13, it warns:

Can not encode '97819050823' into EAN13 Barcode, Size must be 12 numbers
only
No barcode was generated

However if you enter the first 12 digits of an ISBN-13, Inkscape will
generate a bogus EAN-13 barcode, which will probably not scan in book
stores because it has the final checksum digit missing.

I think there's been a mix-up between 12 digit UPC barcodes and 13 digit
EAN-13 barcodes used for book ISBN's. Sorry if this is too obvious and
you knew about the problem already.

If anyone has a barcode scanner available, I would love to do some
quality control testing on this feature, because once it's printed on
the back of the book, it's too late to change :-)

Cheers!

Daniel


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[Aaron Spike-2]

Daniel James wrote:
> I ran into this bug though, while testing 64 Studio 3.0 beta 3, which is
> Ubuntu Hardy LTS based. The Inkscape package is the same binary as in Hardy.
>
> https://bugs.launchpad.net/ubuntu/+source/inkscape/+bug/334073

This bug was fixed in SVN revision 20466.

http://inkscape.svn.sourceforge.net/viewvc/inkscape/inkscape/trunk/share/extensions/Barcode/EAN13.py?r1=20240&r2=20466

Aaron Spike

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[Daniel James-2]

Hi Aaron,

That change to EAN13.py fixes this bug for me, I can now make a barcode
with all 13 digits - thanks! Now all I have to do is get out a
magnifying glass and see if I can decode it :-)

This might seem like an edge case, but this EAN-13 support really is a
killer feature for designing book jackets and other kinds of product
packaging. Otherwise you have to leave a white rectangle and hope the
guy at the printers gets it right. You have to pay extra for them to
make you a barcode too.

> This bug was fixed in SVN revision 20466.

Great, I have marked this in Launchpad as 'in progress' rather than 'fix
commited' because I can't see the patch in the Ubuntu changelog:
 
http://changelogs.ubuntu.com/changelogs/pool/main/i/inkscape/inkscape_0.46-9ubuntu1/changelog

I guess they'll get the change when they package 0.47 though.

Cheers!

Daniel

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[Daniel James-2]

Hi Aaron,

After applying your fix, I've proof-read an Inkscape-generated EAN-13
barcode against the colored-background samples shown here:

http://en.wikipedia.org/wiki/EAN-13

and the bars are all correct :-)

I don't know how well it would work with a typical barcode scanner in a
store - I guess most people in the 'first world' have had that
experience where you get to the checkout and the barcode can't be
scanned by the machine. Happily, Inkscape prints the human-readable
number underneath the barcode, so it can be tapped in manually if
scanning fails.

Cheers!

Daniel

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[Jon Cruz]

On Jun 18, 2009, at 2:39 AM, Daniel James wrote:

I don't know how well it would work with a typical barcode scanner in a 

store - I guess most people in the 'first world' have had that 

experience where you get to the checkout and the barcode can't be 

scanned by the machine. Happily, Inkscape prints the human-readable 

number underneath the barcode, so it can be tapped in manually if 

One minor check you can do is to get someone with a camera phone and scanning app, and see if it picks up. The Android G1 does that, for example.

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