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How to Read Barcodes?
Resource Description
Barcodes are found on virtually all goods that you see in any store. It is a way to encode data in a visual pattern suitable for a scanner to read. Barcodes differ in sizes and shapes, but there are actually only two types of them: one- and two-dimensional. The variation depends on geometrical patterns they consist of.
How to Read Barcodes?
1D Barcodes
1D or linear barcodes represent data by varying the width and spacing of parallel lines. When a laser from a computer scans a barcode, it’s actually scanning through a series of 95 evenly spaced columns and checking to see if each of them is reflecting a lot of laser light or none. Computers only understand ones and zeros, so any of the columns that reflect virtually no light are considered a one, and any of the columns that reflect a lot of light are considered a zero. Black columns absorb light and white ones reflect it. Simply put, computers read white lines only. Probably the reverse of what you might expect.
How does the computer understand 1D barcodes?
The computer reads the columns from left to right. The first column reflects virtually no light so it considers that a one. The next column reflects a lot of light, so it considers that a zero. The computer continues reading the columns all the way across the barcode and comes up with the number which is 95 digits long full of ones and zeros. The number is divided into 15 different sections. 12 of these sections are used for the numbers that you see at the bottom of the barcode. The other three are used as guards. These guards let the computer know where the barcode begins and ends and also where the six numbers on each side begin and end.
This is important because the numbers on the left and on the right are identified based upon different sets of codes. This way the computer knows whether it’s reading the barcode correctly. All the codes on the left side, begin with a zero and end with a one. All the codes on the right side, begin with a one and end with a zero (see an image below).
What does a barcode number mean?
In this example, the first number on the left-hand side, which is outside of the actual
barcode, tells us what type of barcode this is. Zero is a standard barcode, a two is a weighted item, like fruit or
meat, a three is a pharmacy item and a five is a coupon. The next set of five numbers tells us who the manufacturer of
the product is. The second set of five digits tells us the product code. And finally, the last number on the
right-hand side is called the modulo check character and this is another form of error checking.
When the
computer scans the barcode, it processes the numbers to know that it read everything correctly. It performs a
calculation and comes up with a modulo check character. The modulo check character formula is actually based upon the
position of each of the numbers at the bottom of the barcode. It first adds up the digits in the odd-numbered and then
in the even-numbered positions. It multiplies the odd-numbered digits by three and adds that amount to the sum of the
even-numbered digits. So we’ll go ahead and plug in the numbers from our barcode and come up with a final total
of 23. After that, we subtract the result of this formula from the next highest multiple of ten to get the modulo
check character. The next highest multiple of ten after twenty-three is thirty. Thirty minus twenty-three is seven.
Thus we know that we have read the barcode correctly.
2D Barcodes
Linear barcodes are limited to about 20 alphanumeric characters, that is why two-dimensional or matrix codes
appeared. They look like squares and rectangles but actually consist of numerous dots.
The most common type of 2D
codes is QR codes. They consist of black dots arranged in a square grid on a white background. While a 1D barcode
functions in just one dimension, QR codes work in both the horizontal and vertical and can hold up to 350 times the
information of a 1D barcode with finer or higher dpi prints capable of holding more information than fuzzy ones. On
top of that, they have built-in error correction making them less susceptible to damage from water, dust, and more.
What is a barcode scanner?
A barcode scanner is a gadget used for scanning and decoding barcodes. It captures codes on packages with a scanner, and interpreters it to letters and numbers using a built-in or an external decoder. This way, it becomes clear for a computer what product was scanned. Generally, there are three common types of barcode scanners: laser scanners, 1D, and 2D image barcode readers. The first and the second ones are made to read 1D linear barcodes that consist of white and black lines of various width. The main difference between them is that 1D image scanners are better for reading low-quality codes (damaged or under covering). 2D barcode scanners are intended for reading both one- and two- dimensional codes. This technology became very popular replacing 1D scanning all over the world.
The information in the barcode allows you to collect and record data (e.g. price, customer’s address, date of birth, and more). Modern barcode scanners are designed for handling every task you have with the accuracy and ease you need. They are used in numerous spheres, including retail, grocery, shipping, manufacturing, healthcare, government, business, etc. Price, quality, and special features of devices vary according to the company they were manufactured by. At Prime Buy, you can find a variety of cutting-edge barcode scanners from the most popular and trusted brands. Place your order now!
