To read a barcode, especially the common 1D barcodes like UPC or EAN, the process involves recognizing the pattern of black and white lines of varying thicknesses which encode numeric or alphanumeric data. Here is a simplified explanation of how to read a barcode manually:
- Barcodes are made up of black bars and white spaces. Both components are important and represent binary data.
- Barcodes start and end with specific patterns, often "101", which tell the reader where the code begins and ends.
- The middle of the barcode usually has a distinct pattern like "01010" that divides the code into two halves.
- Each number in the barcode is encoded using seven lines (bars and spaces) based on a predefined pattern. For example, the digit "0" is represented by the pattern "3211," which refers to the widths of bars and spaces.
- The barcode contains a check digit, usually the last digit, to verify the accuracy of the read code.
- By measuring the thickness of the bars and comparing them to known patterns, you can translate the barcode into its numeric sequence.
To read a barcode quickly and easily nowadays, a barcode scanner or a smartphone app is used, where the device detects the black and white pattern and decodes it automatically. In summary, reading a barcode involves understanding its structural patterns and using the width of bars and spaces to decode the numbers encoded within it. Modern tools simplify this, allowing instant reading with scanners or smartphone cameras.
