Barcode
What is barcode?
A barcode is a visual, machine-readable representation of data; the data usually describes something about the object that carries the barcode. It can be retail store items, identification cards, and postal mail to identify a particular product number, person, or location.
History
The barcode was invented by Norman Joseph Woodland and Bernard Silver and patented in the US in 1952. Barcodes became commercially successful when they were used to automate supermarket checkout systems.
Types of barcodes
Barcodes are mainly divided into 2 categories
1)One dimensional barcodes — These are the first generation of barcodes and store information by using vertical black and white lines of varying length and thickness. ISBN, UPC, EAN, and Code 39 codes are all one-dimensional barcodes.
2)Two dimensional barcode or 2D codes are the second generation of barcodes. 2D codes are typically square and can store more data than 1D codes. QR Code, Aztec Code, Data Matrix, and AR Code are all two-dimensional barcode formats.
Why we need barcode?
Barcodes are mainly used to classify each product uniquely & read it quickly. But why barcodes, we can simply print the unique decimal number on each product. But the trouble with decimal numbers is:-
1)Misprinted or faded text may result into misinterpretation of code. For example 8 may be read as 3 if misprinted.
2)Reading decimal number upside down may cause mess. For example 6 upside down looks like 9.
3)The reading and interpreting speed of decimal numbers can be quite slow as compared to barcode.
We really need a completely reliable way of printing numbers so that they can be read very accurately at high speeds. That's the problem that barcodes solve.
Reading barcodes
Do you ever wonder how each product in supermarket has unique barcode or what barcode contains or how a barcode is read. Well let us first understand how each barcode is written.
Each barcode has 95 bars. There are total 3 guard bars in every UPC(Universal Product Code) barcode, dividing the whole barcode into 2 sections. First section contains company’s code and other section contains product’s code as shown below
Remaining 84 barcodes are divided into 12 different sections where each section represents one digit. Each digit in a barcode is represented by seven equal-sized vertical blocks.We can represent 0–9 in barcode as follows in barcode.
