With increased automation in every-day life, there was a need for a standard automatic identification system for consumer products.

Many automatic systems for identifying products are based on optical systems. Such systems are based on a beam of light, which scan a bar code on the product. The reflected light is read by an optical system.

Bar code is a code based on a series of dark and bright bands with specific distances between them. It is made by writing dark bands on white background. Usually the bar code appears on a paper label.

In a common bar code the information is coded in one dimension: the width of the dark and bright bands. The length of the bands is just for easy reading and does not contain any meaningful information.