2007-12-05 00:17:14 · 3 answers · asked by Venkataramana G 1 in Computers & Internet ➔ Programming & Design
I have worked in the last 10 years in the field of barcodes...
Most of the barcodes that you see in a daily basis are called "linear barcodes". They are called this because they consist of entirely lines of varying widths.
A barcode consists of a start pattern, a number of codewords that contain the barcode information, and a stop pattern. The start and stop pattern are constant (or only a few exist) that allow you to figure out which type of barcode is present, and where it starts and stops, and it direction.
Each codeword consists of a fixed number of bars and spaces that are a fixed total width for the given number of bars and spaces. As this is accomplished by varying the widths of the bars and spaces, these are also called "width modulated" codes. Each legal combination of bars has a unique value associated with it. Obtaining the value of each codeword allows you to perform the "high level decode", that is translate the codeword values to a string of numbers and characters that represent the data contained in the barcode.
There are also height modulated codes (postal codes), stacked linear codes (PDF417), and matrix codes (maxicode, data matrix and QR code) that encode the data using a method other than width modulation.
If you want to know more (and there is much, much more to know) check out the book "The Bar Code Book" by Palmer.
http://www.amazon.com/Bar-Code-Book-Comprehensive-Machine-Readable/dp/1425133746/ref=pd_bbs_sr_3?ie=UTF8&s=books&qid=1196875939&sr=1-3
2007-12-05 04:35:28 · answer #1 · answered by brunt 4 · 0⤊ 0⤋
very confusing stuff. look on to a search engine. it could help!
2014-12-02 14:48:15 · answer #2 · answered by Anonymous · 0⤊ 0⤋
getting back t u
2007-12-05 00:33:02 · answer #3 · answered by konsultant 3 · 0⤊ 0⤋