Barcode

A barcode (also bar code) is a representation of information as a group of parallel lines (or concentric circles, in at least one symbology) of various widths and spacings. The mapping between messages and barcodes is called a symbology. Symbologies can be classified into two groups in two different ways:

• Continuous vs. discrete: Characters in continuous symbologies abut, with one character ending with a space and the next beginning with a bar, or vice versa. Characters in discrete symbologies begin and end with bars; the intercharacter space is ignored, as long as it is not wide enough to look like the code ends.
• Two-width vs. many-width: Bars in two-width symbologies are wide or narrow; how wide a wide bar is does not matter, and may vary from one character to the next. Bars in many-width symbologies are all multiples of a width called X; usually bars of width X, 2X, 3X, and 4X are used.

Table of contents 1 Examples of barcodes 2 Types of barcodes 2.1 Linear barcodes 2.2 2-D barcodes 2.3 External link:

Examples of barcodes

Code 128-B:

UPC:

Types of barcodes

Linear barcodes

Symbology	Cont/Disc	Two/Many	Uses
Plessey[?]	Continuous	Two	Catalogs, store shelves, inventory
UPC	Continuous	Many	USA retail
EAN-UCC			Worldwide retail
Codabar[?]	Discrete	Two	Libraries, blood banks, airbills
Interleaved 2 of 5[?]	Continuous	Two	Wholesale
Code 39[?]	Discrete	Two	Various
Code 93[?]	Continuous	Many	Various
Code 128[?]	Continuous	Many	Various
Code 11[?]	Discrete	Two	Telephones
POSTNET[?]	Continuous	Tall/short	Post office

2-D barcodes

Symbology	Notes
3-DI	Developed by Lynn Ltd.
ArrayTag	From ArrayTech Systems.
Aztec Code	Public domain.
Small Aztec Code
Bullseye	This was the barcode tested in a Kroger store in Cincinnati. It used concentric bars.
Codablock	Stacked 1D barcodes.
Code 1	Public domain.
Code 16K	Based on 1D Code 128.
Code 49	Stacked 1D barcodes from Intermec Corp.
CP Code	From CP Tron, Inc.
Data Glyphs	From Xerox PARC.
Data Matrix	From RVSI Acuity CiMatrix.
Datastrip Code	From Datastrip, Inc.
Dot Code A
HueCode	From Robot Design Associates. Uses greyscale or colour.
INTACTA.CODE	From INTACTA Technologies, Inc.
MaxiCode	Used by United Parcel Service.
MiniCode	From Omniplanar, Inc.
PDF417	The most common 2D barcode. Public domain.
Micro PDF417
QR Code	From Nippondenso ID Systems. Public domain.
SmartCode	From InfoImaging Technologies.
Snowflake Code	From Marconi Data Systems, Inc.
SuperCode	Public domain.
UltraCode	Black-and-white & colour versions. Public domain.

See also : Global Trade Item Numbering, RFID

External link:

• Online Barcode generator (http://barcodesinc.com/generator/)
• the barcode de facto standard (http://www.ean-ucc.org).