Image-based readers: Codes of conduct

THE FOOD industry in China continues to battle with safety issues. In April this year, a family-run business in Huai’an city, Jiangsu province, was discovered to have put additives normally used for dyeing and printing, into the duck blood that they sold, according to Ecns.cn. The purpose was to make the popular food item look more appealing before it was distributed to local markets. The shop owners also used chicken blood instead of duck blood.

In another report from Want China Times, Luo Guo’an, a researcher with the sociology department of the Guangxi Academy of Social Sciences, said that these food scandals were a result of “loose supervision, improper management, imperfect laws and regulations, and manufacturers' eroding credibility.” He also mentioned that the authorities need to improve food safety laws by extending the range of supervision and enforcing harsher penalties for offenders. He added that a credibility system has to be put in place to regulate food manufacturers.

Establishing security

Whilst it appears that laws and education have to be stepped up to deter such crimes in the long term, technology can also play a pivotal role. By using 1-D barcodes and 2-D codes, countries in Asia can create a secure environment to ensure food safety throughout supply chains. In this manner, legitimate manufacturers can establish credibility for their brand names – as well as the distribution system – with products that are distributed both locally and overseas. 

Today, an increasing number of manufacturers are harnessing the power of 2-D codes. The advantage of these codes is that they contain much more information than their 1-D barcode predecessors. This allows the manufacturers to store more information for greater traceability in the supply chain. In recent years, 2-D codes have also gained popularity at the consumer level, taking advantage of the rise in smartphone technology.

In May, it was reported by Mobile Commerce News that Nestlé has included QR codes on its product packaging. Consumers simply have to capture an image of the codes using their smartphones, which then direct them to a website that reveals the manufacturing process, packaging, distribution and ingredients used for the product. For example, consumers learn that the cocoa and sugar used in the Kit Kat bar come from fair trade certified farms. The site also tells the story of how the company plays its part in sustainable practices and environmental conservation in farming activities.

Barcode apps are also gaining popularity and are changing the way that consumers shop. Using free apps like Shopsavvy and Red Laser, smartphone owners can simply scan a product code at a store, according to a report by Pittsburgh’s Action News. The software then presents a list of other stores that offer the same product and their prices. This allows consumers make comparisons to find the best price; or to approach the store they are at to do a price match.

Product traceability

Higher up in the supply chain, food producers utilise barcodes to ensure that the correct information has been attached to products. A factory manufactures and packages milk powder for distribution in overseas markets. Because of the sensitive nature of the products, accurate and precise barcode reading is necessary to make sure that the right products are identified and shipped to customers. The factory originally utilised a label verification system which could only read ladder barcodes. Although a separate system was created to read the picket fence barcodes, the readers could not cope with the high production speed of 97 cans per minute.

Production managers therefore saw the need to upgrade to a more reliable system that could achieve 100% read rates whilst eliminating packaging errors.  DataMan fixed-mount image-based readers were selected for the job as they allow all images of the barcodes to be viewed in real-time. This enables the system to immediately determine whether or not a code has been read. These readers provide high resolution, image review (while running via Ethernet), high read rates, and a rugged design. Besides meeting the requirements for 1-D code reading, the readers are also able to read 2-D codes that will be used on products in future.

In order to read the picket fence 1-D barcode on the curved surface of a can, each item has to be rotated. As a solution to cope with the convex structure and reflective surface of the packaging, six fixed-mount readers are deployed in a row along the can turner. They are arranged into three groups of two. As the can is rotated 360 degrees, each group of cameras is triggered. In this manner, two of the readers are able to read the code on each can.

If incorrect barcodes or ‘no-reads’ are detected, alarm beacons and display screens alert the operators. The latter will then proceed to halt the production line and remove the defective product. This ensures that the can does not move into the packaging area. A report on read rates can be generated, to allow for the easy monitoring of production performance. The system also links to the site’s inkjet printers and case printers to ensure that the correct dates are printed on each pack, ready for shipment.

The system is therefore able to eliminate false line stoppages due to ‘no-reads’. It also prevents incorrect tins from being packed; and uses print control to ensure that the correct dates have been applied.

Beyond the codes
Besides ensuring that the correct barcodes are affixed on products, image-based readers also check printed information such as manufacturing and expiry dates. Since these dates tell consumers if a product is still safe for consumption, it is vital that they are accurate and legible. At another facility that produces canned food, human operators were previously deployed along its production lines to manually inspect the cans that passed by.
Although this was still feasible at low production speeds, it became more difficult for the staff to pick out problems as volume increased over time. Moreover, there were limitations with human operators and they could only determine the presence of the printed information. This means that any incorrectly printed dates would have passed through the quality control process unchecked. Besides, operators are subject to other variables such as fatigue (especially towards the end of a work shift) and mood swings – all of which affect the standards of inspection.

After the installation of image-based cameras however, the facility has been able to effectively identify cans without date codes, as well as misplaced cans from a different production batch.  The system is also able to validate the expiry dates of milk products. Using Pat-Max technology, even cans that are upside-down can still be read quickly and reliably.

With the automated inspection system, the number of operators on each shift has been reduced from eight to just one, allowing human resources to be redistributed to other areas in the facility.

Deciphering codes

Barcodes and 2-D codes are machine readable symbols that store identifying data about the part or product that they are associated with. The technology provides fast and reliable data collection, to ensure part or product traceability and error-proof assembly processes – while also helping to enhance customer service.

When these codes are read by a scanner, they are decoded, recorded, and processed. This is to extract the data for a variety of uses such as pricing, order fulfillment, traceability, sorting, shipping, etc. Today, there are different types of barcodes. These include:

One-dimensional barcode: A 1-D barcode is the typical style that most people are familiar with. All the information in the code is organised horizontally in bar and space widths, and read from left to right using a scanner. Many versions of 1-D codes store only numerical data while others can encode additional characters. The height of the code varies, based on the space available on a product and the ability of a barcode reader to read a small or large-sized barcode.

Postal codes: This type of code lies somewhere in between a 2-D code and a 1-D linear barcode. Instead of encoding data in the black bar and white space widths, these primarily use the height of the bars. Most postal codes only use numbers, although a few are now starting to include letters as well.

2-D matrix codes: With 2-D matrix codes, the data is encoded as black-and-white ‘cells’ (small squares) and arranged in either a square or rectangular pattern. Besides being capable of encoding large amounts of data, the matrix code improves readability and offers resistance to poor quality printing. They also include redundant data to ensure that the code is still readable, even if one or more cells have been damaged.

Stacked linear barcodes: A stacked linear barcode is one of two types of 2-D barcodes. It is made up of multiple linear barcodes that are layered on top of each another, to allow more information to be encoded. To fully decode the data however, the reader has to simultaneously read the code both horizontally and vertically.