Bar codes are a collection of bars (stripes) encoded in such a way that they represent a string of characters. They are designed for machine scanners and are therefore not easy to read for humans. In addition to the one-dimensional bar codes, like the one depicted below, there also exist two-dimensional bar codes (often called matrix codes). Matrix codes can store far more data than the original bar codes, because the data is stored in two dimensions.

SINTEF has experience in bar code reading since 1995 when we did a project on bar code reading with a low resolution camera for Tomra Systems ASA. Utilizing our prior knowledge about the measuring situation and the physical properties of the imaging system we where able to read bar codes with as low resolution as 3 bar code modules(bars) per pixel element. See picture on the right and related article. Later on we have been working for Tomra Systems ASA building an industrialised bar code reader for bottle recycling machines.   

We have also been working for Cargoscan AS (in cooperation with Tordivel AS) with the development of a high capacity bar and matrix code reading system for the transport industry. In order to cope with the plastic liners on the parcels we had to make a novel (and now patented) lighting system and in order to handle the high troughput and huge datarates we also had to develop hardware specific realtime algorithms for the decoding.

The new cameras on mobile phones open up new possibilities for bar code reading on the fly, with a great user potential. SINTEF has developed a matrix bar code reader for PDA's and mobile phones, a matrix code reader used for "digital graffiti" (CybStickers) and we have also developed a reader for standard one-dimensional bar codes in cooperation with Pelias Mobile.    

In designing bar code readers not only image analysis, pattern recognition and software algorithm design proved useful, also knowledge about the physical measuring situation, optics, illumination, camera and imaging technology contributed to the robust solutions. The result has been bar code reading systems adapted and optimized for the relevant applications.

Application examples:

• Transport industry – high capacity bar and matrix code reading
• Bottle and beverage can recycling
• Retail industry 
• Bar and matrix code reading on mobile phones and PDA's
• Orders, booking and price comparison - take a picture of the bar code instead of doing the tedious typing of text and numbers
• Delivery services
• Stock holding
• Easy reading of large data contents written on physical objects - Name and address on a business card, a web address found in an advertisement or even a game
• Reporting for surveillance