if a barcode is scratched is it still readable by a sensor or checkout counter?

if a barcode is scratched is it still readable by a sensor or checkout counter?

Best answer:

It really all depends on where the scratch is. The types of barcodes you’re referring to are called retail codes and typically consist of UPC and EAN barcode types. These are the barcodes you see on just about every single grocery item in a store.

If they are scratched there is a very good chance they can still be read. Even though most barcodes are close to an inch high, it takes less than an eighth of an inch of height to be readable. The barcode scanner is simply drawing a very thin line through all bars of the barcode to decode it. So when you look at the barcode if you can mentally draw a very thin line from end to end through any part of the barcode the barcode scanner will still read it.

In some cases even if a whole bar of the barcode is damaged or missing some barcode scanners can still read it. There are some barcode scanners that do what is called stitching of the barcodes. Stitching simply means the barcode scanner decode algorithm knows the bar/space pattern well enough that it can still read a barcode if there is a missing bar or space.

The above all apply to the retail type codes which are considered linear or 1D barcodes. There are also 2D barcodes which are not common in retail yet. But they are getting very common in manufacturing, transportation and healthcare. 2D barcodes are far more efficient than 1D barcodes. 2d barcodes can encode much more data than 1D barcodes in the same physical space. They also have error correction built in. Which means you can actually remove parts of the barcode and it will still be readable. But not all barcode scanners are 2D capable yet. It’s just a matter of time before they become more mainstream than they are today.

Common 1D barcode types are UPC, EAN, Code 128, Code 3 of 9, Interleaved 2 of 5, MSI, Plessey etc. There are many more.

Common 2D barcode types are Data Matrix, Aztec, QR Code, Han Xin and many more.

Many people consider PDF417 (the barcode on the back of many US drivers licenses) a 2D barcode. Technically it is a stacked linear barcode.

For more information on barcodes and barcode scanners check out my website below.

Tags: Barcode, checkout, counter, readable, scratched, sensor, still

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