Data Matrix  


Data Matrix is a 2D matrix symbology developed in 1989 by International Data Matrix.
It has a finder pattern of two solid lines and two alternating dark and light lines on the perimeter of the symbol. These patterns are used to indicate both orientation and printing density of the symbol.
Data Matrix is designed with a fixed level of error correction capability.
Data Matrix symbols are divided into two main subsets
Versions referenced ECC-000 to ECC-140 are using convolutional coding for error correction.
The second subset is referenced ECC-200 and uses Reed-Solomon error correction techniques.
Thanks to its ability to encode approximately fifty characters of data in a symbol of 2 or 3mm in size Data Matrix is especially popular to mark small items, for example integrated circuits and printed circuit boards. The code can be read with only a 20 percent contrast ratio. The code is read by CCD video camera or CCD scanner.


Quick Response Code (QR Code) is a square matrix symbology was invented by Denso (Nippondenso ID Systems) in 1994. QR Code is a two-dimensional symbology containing dark and light square data modules
The finder pattern consists of three square position detection patterns located on three corners of the code symbol.
One of the main features of the symbology is its ability to encode Japanese Kana-Kanji characters set.
Four levels of error correction are available. A quiet zone of four modules wide is required around the perimeter of the symbol.
QR Code is designed for rapid reading by CCD array cameras and image processing technology thanks to the layout of the finder pattern.
QR Code is used to mark small items.


PDF417 (Portable Data File) is a multi-row, variable-length stacked symbology, invented by Ynjiun Wang (Symbol Technologies) in 1991.
The symbol is composed of a stack of 3 to 90 rows. A PDF417 symbol character, or codeword, consists of 17 modules arranged into four bars and four spaces (thus the number "417"). PDF417 offers a maximum data character capacity of 1,850 text characters, or 2,710 digits or 1,108 bytes.
PDF417 is designed with selectable levels of error correction from 0 (zero) or no error correction to 8 (eight), the highest level. Each symbol has a start and stop bar group that extends the height of the symbol. A quiet zone of two X-dimensions is required around the symbol.
The symbology can be read by laser scanners, linear CCD scanners or 2D imaging devices.
Codabar, also known as USD-4 code, NW-7, and 2 of 7 code, is a numeric barcode symbology. Each character is composed of seven elements: four bars and three spaces.
Codabar can encode up to 6 digit symbols, and four start/stop characters, to convey additional information. The start/stop characters must be used in matching pairs and may not appear elsewhere in the barcode.
Codabar is used by the blood bank industry, and implements a concatenate feature. Two adjacent symbols will be concatenated by the reader into a single message.
Codabar is used in libraries, blood banks, the overnight package delivery industry, and a variety of other information processing applications.
    Code 128  
Code 128 represents characters by the arrangement of 3 bars and 3 spaces with each bar or space being 1, 2, 3 or 4 elements wide. This coding symbology has tight print tolerances, so it is only recommended n applications where high standard of print quality can be achieved.
Code 128 is a very high density alphanumeric bar code. The symbol can be as long as necessary to store the encoded data. It is designed to encode all 128 ASCII characters. It uses the least amount of space for data of 6 characters or more of any 1-D symbology.
Each data character encoded in a Code 128 symbol is made up of 11 black or white modules. The stop character, however, is made up of 13 modules. Three bars and three spaces are formed out of these 11 modules. Bar and spaces can vary between 1 and 4 modules wide.
    Code 39  


Code 39 (often referred to as 3 of 9) was developed in 1974 by Intermec for applications requiring an alphanumeric code.
It is a discrete, self-checking, variable length symbology. Widely adopted by public offices, parcel-delivery industry and the retail sector, it is now the most used industrial code.
It allows coding  43 characters (i.e. alphabetic, numeric and 8 additional characters) including a character reserved for use as a start/stop character.
The main reasons for the popularity of the barcode are its ability to code alphanumeric data, reliability and easy printability. Self-checking option is implemented, but security level degenerates rapidly because of poor print quality.


European Article Numbering system is an international standard bar code for retail food packages. It is similar to UPC, widely adopted by the grocery industry 
The EAN-13 bar code type has 12 data characters. An EAN-13 symbol contains the same number of bars as the UPC-A but encodes a 13th digit into a parity pattern of the left-hand six digits. This 13th digit, in combination with the 12th digit, represents the country code. The JAN-13 (Japanese Article Numbering system) is a special application of EAN-13.
Scanners equipped to read EAN symbols can read UPC symbols as well. However, UPC scanners will not necessarily read EAN symbols.
The UPC symbology is ideal for coding products, it can be printed and scanned with any package orientation provided the symbol faces the scanner. The UPC format can be scanned by hand-held wands and can be printed by equipment in the store. UPC-A has a First Pass Read Rate of 99% using a fixed laser scanner and has a substitution error rate of less than 1 error in 10,000 scanned symbols.
    Interleaved 2 of 5  


Interleaved 2 of 5 (often referred as I25 and ITF) is a high density, self-checking, continuous barcode symbology. It represents characters by the arrangement of two wide bars in a total of 5 bars, which gives 10 combinations. By arranging the spaces in a similar way pairs of digits can be coded. This code encodes numeric data only (i.e. numeric characters 0-9).
The "Interleaved" part of the name comes from the fact that the first digit is encoded in the bars and the next digit is encoded in the spaces. The encoded digits are "Interleaved" together. There are five bars, two of which are wide and five spaces, two of which are wide.
It is a slightly more compact barcode than Code 39 (a print density of 9 digits per inch compared to code 39 s 10 digits per inch), but it is not considered secure. Interleaved 2 of 5 is suitable to encode general purpose all-numeric data. It is mainly used in the distribution industry.