- very easy print, can be printed on printers with small DPI
- if barcode is damaged, no problem read encoded value visually in human part of image
- for developers : easy programming, verys imple encoding algoritm, easy check digit calculation method
- very small capacity - in practice max. to 20-30 encoded characters
- not very high security - only one or two check digits, when barcode image contain some errors, can be unreadable
- must contain quietzone around the barcode image
- No error correction, only error detection
2 of 5 Interleaved (ITF)
ISMN with 5 digits add-on
UPC version E1
For example PDF417 is often referred to as a 2D symbology. However, it is not a true matrix code. It is a stacked linear code, consisting of multiple rows of short linear codewords. It allows bars and spaces to have up to 6 different widths and as such it can be adversely affected by binarization at lower samples per module.
They use a regular grid of possible cell positions, and the presence or absence of a cell in a grid location encodes the data.
Matrix barcodes have higher capacity as linear barcodes, have implemented powerfull error correction.
3D barcode is any linear barcode that is embossed on a surface. The code is read by using differences in height. Of course, we can't print this on classic laser or InkJet printer.
Barcode symbologies used in post office. More country have own specifications.
- Some symbologies can be derived from Code39 or Code93 (Danish, French, Dutch postal symbologies)
- use own encoding system ( Telepen, CPC )
- Some use 4-state symbology ( BPO4State, Royal Mail, Singapoore postal, Australia post, Japan Post, Korean, Deutsche 4 state, IntelligentMail...), information isn't encoded into sequence lines and bars with different width, but encoded using lines in four different height ( if we separate bar in height to three same parts ):
Basic elements of Postal barcodes:
- T - Tracker
- D - Tracker, Descender
- A - Tracker, Ascender
- H - Tracker, Ascender, Descender
- ... or use 2-state encoding - lines are full in height or bottom half ( PostNet ) .
Composite barcodes - combined linear and stacked barcodes into one symbol