Bado unanichanganya muhishimiwa.Ungeandika maana yake na maelezo kwa kiswahili.
When you use the self-checkout counter at a supermarket, you scan the barcodes of your purchases. The barcode contains data about the item it’s attached to, so the electronic cashier immediately knows you’re buying a bag of Kettle salt & fresh ground pepper potato chips the moment you scan it.
Well, the QR – which stands for “quick response” – code is basically a barcode on steroids. While the barcode holds information horizontally, the QR code does so both horizontally and vertically. This enables the QR code to hold over a hundred times more information.
How did it come about?
In the early 1990s, barcode scanning was becoming increasingly laborious. Each barcode could hold just 20 characters of data, so it often took multiple barcodes on a box to convey what was inside. When a Japanese engineer by the name of Hara Masahiro – who made barcode scanners for a living – learnt of the problem, he set about solving it.
Together with his team, Hara developed a two-dimensional barcode in the shape of a square, tackling the issue of limited data capacity. However, when these new barcodes were printed with other forms of text next to them, scanning machines could not pick them up. This rendered the square barcodes impractical.
This impasse was overcome one day when Hara, looking out of the subway window on the way to work, noticed that skyscrapers stood out distinctively from the rest of the landscape. He began searching for ways to distinguish the square barcodes from text.
Finally, he landed on the solution of embedding three small squares (with a specific ratio of black-to-white areas) at the corners of the new barcode, enabling scanners to recognise it instantaneously.
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