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The PDF417
barcode is one of the four most popular 2D barcodes yet to be
developed. PDF417 barcode is a two-dimensional stacked barcode
that can store large amounts of data. It was invented by Dr.
Wang Yinjun of Symbol Technologies in the United States in 1991.
PDF stands for
Portable Data File, and 417 means that each character consists
of 4 bars and 4 spaces, with a total of 17 modules. PDF417
barcodes are commonly used in applications such as ID cards,
driver's licenses, and shipping labels.
Three other
common 2D codes are QR codes, DataMatrix, and MaxiCode; several
others were developed between 1988 and 1995, but they never
became widely used.
The name PDF417
comes from an acronym for "Portable Data File". "417" is added
because there are 4 bars and 4 spaces arranged within every 17
module codewords (i.e. characters). These characters or clusters
have a specific formula for the size of each bar in the cluster.
PDF417 has gained
popularity in the shipping industry and is often used by FedEx.
It was also chosen to print postage for the US Postal Service,
often used for airplane boarding passes. Also, you'll often see
it on driver's licenses and other ID cards. Other applications
include manufacturing parts tracking, lottery tickets, patient
wristbands and trade show lead retrieval systems.
PDF417 consists
of 3 to 90 lines of data and can encode up to 1850 ASCII or 2725
numeric characters. This code is designed to be scanned with a
slightly modified raster laser scanner or a linear CCD scanner
such as the DS6708 2D Imager. NOTE: At the high end of data
encoding (over 800 characters), you may find it better to switch
to the macro PDF version, depending on the data type, the level
of error correction chosen, and the scanner used.
Unlike square
DataMatrix or QR codes, PDF417 is actually a high-density,
stacked linear symbology with a rectangular shape. It is stacked
to hold large amounts of data¡ªtypically 100 to 200
characters¡ªand the aspect ratio can be adjusted to accommodate
space constraints. It has varying levels of redundancy built in,
so up to 50% of the code can be corrupted, but the data can
still be recovered. But overall, PDF417 takes about four times
the space required by DataMatrix or QR codes. |