How a QR code works
> Barcodes were proving inadequate - they can only be read at certain angles and didn't store much data relative to their size<p>It's the scanner that dictates what angles a barcode can be read at.  A 2D barcode scanner (which you need to read QR codes AT ALL -- or even a smart  phone running Cognex's barcode scanner app) can read regular 1D barcodes from absolutely any orientation.<p>You can reduce the size of 1D barcodes to increase data density:<p><a href="http://www.barcodebootcamp.com/labels/barcode-density.html" rel="nofollow">http://www.barcodebootcamp.com/labels/barcode-density.html</a><p>It's rarely done because easy decoding is usually the priority.<p>Plus, you can make 1D barcodes extremely small vertically, as commonly seen on the edge of USPS envelopes:<p><a href="https://www.wsel.com/sites/default/files/IntelligentMailBarcode_LandingPage.png" rel="nofollow">https://www.wsel.com/sites/default/files/IntelligentMailBarc...</a><p>...and that way store several lines of 1D codes holding much more information in the space of one QR code.<p>2D codes are useful in some circumstances, but they're not <i>better</i> than 1D barcodes.