Bug 11601 – mBarcode does not recognize inverted barcodes

Bug 11601 - mBarcode does not recognize inverted barcodes


Summary:	mBarcode does not recognize inverted barcodes

Status:	RESOLVED WONTFIX

Product:	mbarcode
Component:	libdmtx
Version:	unspecified
Platform:	All Maemo

Importance:	Unspecified major (vote)
Target Milestone:	---
Assigned To:	unassigned
QA Contact:	general

URL:
Keywords:

Depends on:
Blocks:
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Reported:	2010-11-21 22:19 UTC by Svenn-Arne Dragly
Modified:	2011-02-10 11:08 UTC (History)
CC List:	2 users (show)

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Description Svenn-Arne Dragly (reporter) 2010-11-21 22:19:29 UTC

mBarcode will not recognize inverted bar codes upon scan. This is due to lack
of inverted bar code support in the zbar library. A workaround could be to add
inversion in the code, passing both a non-inverted and inverted image to the
decoder. 

This will probably cause higher CPU usage, but having this feature implemented
should have higher priority. 

To avoid too much collateral damage, we could implement a user setting to
disable inversion.

Comment 1 Simon Pickering maemo.org

2010-12-13 21:11:33 UTC

1D codes and QR scan perfectly ok inverted (both provided by ZBar), but in a
quick test I couldn't get a DataMatrix barcode to scan upside down, so it looks
like this is the issue here.

Comment 2 Dirk-Lüder 2011-02-10 04:50:06 UTC

(In reply to comment #0)
> mBarcode will not recognize inverted bar codes upon scan. This is due to lack
> of inverted bar code support in the zbar library. A workaround could be to add
> inversion in the code, passing both a non-inverted and inverted image to the
> decoder. 

Do you mean inverted as in upside down, or as in colours inverted? (is that
even allowed?)

I know it does some codes upside down, upc/ean seems to work reliably, even
rotated 90 degrees.

Comment 3 Simon Pickering maemo.org

2011-02-10 11:08:39 UTC

Assuming this is a problem with dmtx barcodes, I'd prefer to wait for support
in libdmtx for scanning inverted barcodes (or even barcodes at arbitrary
angles) rather than adding in a hack to mBarcode.

Therefore unless someone has a compelling usecase requirement I'm going to mark
this WONTFIX.

If someone does really want this functionality, it could be added at the
expense of even slower datamatrix scanning speed.