Wednesday, March 17, 2010

QR Code

QR Code:
The two dimensional barcode (matrix code) is named as Quick Response (QR) code. The decoding response of the QR code is comparatively very fast.
The QR code is first created by Japanese organization Denso-wave in 1994 for tracking purpose. The main aim was to decode it by scanning equipment easily. Now a day’s it’s widely used to store address and URL in magazines, for monitoring the product ID or price values, tracing the admin work and showing the images on screen. Most of the mobile devices have inbuilt QR code Reader application.



QR code contains the information in both (vertical and horizontal) directions. QR code can hold comparatively more information that one direction Barcode.
Date Type:
User can encode Numeric, Alphanumeric, symbol, Kanji, Kana, Hiragana, binary and control codes in QR code. QR code can contain up to 7,089 characters in one symbol. The information stored in QR code depends upon the mixing of numbers, Alphanumeric and other characters.
Data Capacity:

Error Correction Level:
The error correction algorithm can recover the data from the QR symbol even when the symbol is very damage.
The ECC levels are:
L Level: Approx 7% code can restored
M Level: Approx 15% code can restored
Q Level: Approx 25% code can restored
H Level: Approx 30% code can restored
Recognition rates:
The recognition algorithm can overcome multiform defects as scratch, damage, fuzzy image etc. The recognition rate depends upon the QR symbol image quality and number of pixels.
QR Symbol Version:
The QR symbol version range is 1 to 40.Each version has different module configuration and the range of encoded characters. The version 1 module 21x21 version2 module 25x25 and so on. Every version has different encoding data capacity.
QR code Reader:
The QR code Reader is the application which can decode the QR code. Now a days so many mobile applications are there where application uses the camera fetch the image from either paper or wall or from other medium and decode the QR code and display the result on the Screen.
I have also developed an application “QR Reader” for Symbian devices where application reads the image through camera and process the image in decoding library and send the QR data as a SMS to some distant receiver or open the link as webpage.