PDF 417

PDF 417 is a barcode that is used to encode large amounts of information. The word ”barcode” is a widely used term and known to the vast majority of people. They contain a certain amount of information and are used to recognize an item both physically and online. However, there are two groups of barcodes: linear (or one-dimensional) and two-dimensional. This article will talk about the latter, specifically the PDF 417 format, which was developed in 1991 by Symbol and later acquired by Motorola in 2007.

What is PDF 417?

PDF 417 is currently regulated by ISO/IEC 15438:2006 – Information technology — Automatic identification and data capture techniques — PDF417 bar code symbology specification

It is a grouped barcode that can be used to encode large amounts of information in different codes

Each individual pattern consists of exactly 4 bars and 4 spaces, and each of them is 17 units long. This is where the number 417 comes from. PDF 417 can encode up to 1,800 ASCII characters per barcode or up to 1,100 binary characters per symbol. Once the width of the symbol is set, the height of the symbol depends on the embedded information. If the amount of information to be stored is greater than what can fit in one symbol, several symbols can be linked to reach the required storage capacity.

Each one consists of 3 to 90 rows, each row being a small linear barcode. Each row has:

• A quiet zone. This is the minimum white space required before the barcode begins.
• A start pattern which identifies the format as PDF 417.
• A row left codeword containing information about the row (such as the row number and error correction level, which we will see later).
• 1-30 data codewords, which are groups of bars and spaces representing one or more numbers, letters, or other symbols.
• A row right codeword with more information about the row.
• A stop pattern.
• Another quiet zone

All rows have the same width and each one has the same number of codewords.

A single PDF 417 symbol can contain up to 1850 alphanumeric characters, 2710 digits or 1108 bytes. Due to internal data compression algorithms, the data capacity will depend on the structure of the information being encoded. The maximum capacity depends on the printing space and resolution of the printer.

PDF 417 standard generally states that text should be encoded according to the CP437 code page.

A built-in error correction method is provided based on Reed-Solomon algorithms which the user can set between level 0 (error detection) and level 8 (maximum error correction). Suggested levels are between 2 and 5, but the optimum value will depend on the amount of data, print quality of the PDF 417 symbol and decoding capability.

PDF417 supports the “Structured Append” feature, in which case the symbology is called PDF417 Macro or PDF Macro. In theory, up to 99999 symbols can be appended within a single document.

Main uses

It is mostly utilized in logistics (especially in the automotive industry), transport systems (e.g. for shipping labels), identification (e.g. driver licenses, passports, eSignatures) and document management.

PDF 417 has become popular in the transportation industry and it’s frequently used by FedEx. It was also chosen for printing U.S. Postal Service postage and it is commonly used for boarding passes.

Other uses include manufacturing parts tracking, lottery tickets, patient wristbands, and tradeshow lead retrieval systems

How does it differ from other types of codes?

Viafirma allows the user to configure the eSignature stamp, choosing among different symbols for the server-based signature (which is performed without required user interaction). This is done with a digital certificate that is stored on the software.

The following is a comparison of the different types of barcodes available in our solutions:

Barcode 128: 1D with high data density. Wide application throughout all areas. There are 3 sets of characters that are automatically changed.
QR Code: 2D for encoding text or bulk data in a single code. Often used for Mobile-Tagging with cell phones.
QR Barcode 182: Both electronic symbols in the document.
Reduced QR Code: Same shape as the second one but slightly smaller.

The following is a comparison of the different types of barcodes available in our solutions:

• Barcode 128: 1D with high data density. Wide application throughout all areas. There are 3 sets of characters that are automatically changed.
• QR Code: 2D for encoding text or bulk data in a single code. Often used for Mobile-Tagging with cell phones.
• QR Barcode 182: Both electronic symbols in the document.
• Reduced QR Code: Same shape as the second one but slightly smaller.

PDF 417: the solution to speed up times and improve the quality of the data collected

For check scanners this barcode is important because it is the standard format for most state-issued driver’s licenses and ID cards. Many banks and credit unions are using them to capture pictures of clients’ identity documents at the teller window, therefore the ability to identify and read them correctly is key to obtain and validate the data.

In fact, our Viafirma Documents solution works in a similar way. It includes the possibility of scanning this symbol when creating a new signature request, so that the blanks where we fill in the signer’s data will be completed automatically. This feature will speed up the time spent on filling the containers and will improve the quality of the data collected. One clear example is the Colombian ID card, which includes this code on the back with information on the citizen, which can be automatically sent to the form.