How to barcode scanners instantly detect what an item is, despite the barcode being at any angle and often on a crinkled surface, completeley changing the look of the code from the scanner’s perspective?

Question

How to barcode scanners instantly detect what an item is, despite the barcode being at any angle and often on a crinkled surface, completeley changing the look of the code from the scanner’s perspective?

In: Technology

Answer 1

The barcode is made of white and black bars. Every digit has a seven bar pattern. The code has also a divider in the middle, so we got left and right side.

On the left, every number have an odd number of black bars and an even number of white bars. On the right, the colors are reversed, so what was white is black and vice versa.

I don’t know the code, but let’s say zero is 3 black followed by 4 white on the left. When on right, it will be 3 white, 4 black.

That way, you could know when it’s upside down, or sideways, and read in the right direction.