Decode barcodes on cropped specimen images

quicklizard99 commented 10 years ago

Metadata fields need to be populated from data decoded from barcodes on cropped specimens images. Decoding should be robost and require as little human intervention as possible.

quicklizard99 commented 10 years ago

Some good descriptions at Wikipedia and Inlite. Within the museum have least:

Code 128 - 1d - herbarium sheets
Data Matrix - 2d - microscope slides, iCollections

The ideal is we pass the cropped specimen image to a decoder, which returns the data encoded within (ideally also the types and locations) of all barcodes on the image.

OpenCV does not have barcode decoders. This has been slated for a while, e.g. for the 2014 GSoC with Claudia Rapuano as mentor. See also this discussion.

I have investigated the following open-source barcode decoders

zbar

http://zbar.sourceforge.net/
https://github.com/ZBar/ZBar/blob/master/python/README
https://github.com/herbyme/zbar/blob/master/python/examples/scan_image.py
Open-source library for Python
Fast
Can decode many different types of barcode but not handle DataMatrix (requested on at least two previous occasions)
- http://sourceforge.net/p/zbar/discussion/1072195/thread/13240cf7/
- http://sourceforge.net/p/zbar/discussion/664595/thread/25769670/
No development since 2012
Requires compilation

libdmtx

http://www.libdmtx.org/
http://sourceforge.net/p/libdmtx/libdmtx/ci/master/tree/
Open-source cpp library
Can be very slow - several 10s of seconds for a large image; it is possible to set a timeout
Requires compilation
No development since 2011 and not likely to be any soon
Not a python library. We could create our own python wrapper.

zxing

https://github.com/zxing/zxing
Java library
Used to have a cpp version but it appears that this is no longer maintained
A QT port has been made

OpenCV + decoder library

None of these three open-source decoders is capable of reliably locating and decoding barcodes within the example specimen images that I have.

I coded up this strategy:

Use OpenCV to identify areas of the image that might contain barcodes
Pass each candidate area through one or more of the open-source decoders

This method works very well for some images by not reliably across the example cropped specimen images that I have.

Next step

Look at commercial decoders.

stefanv commented 10 years ago

Could you place a selection of images online for which this should work? It would help a lot in coding up some test solutions.

quicklizard99 commented 10 years ago

Thanks @stefanv. I will share a few hundred example images, along with some code and results, although probably not until the start of next week.