QR code

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QR code (abbreviated from Quick Response code) is a type of matrix barcode (or two-dimensional barcode) first designed in 1994 for the automotive industry in Japan. A barcode is a machine-readable optical label that contains information about the item to which it is attached. In practice, QR codes often contain data for a locator, identifier, or tracker that points to a website or application.

History

The QR code system was invented in 1994 by Denso Wave, a subsidiary of the Toyota supplier Denso. The initial design was influenced by the need for a barcode that could be read quickly and could store more information than the traditional UPC barcode.

Structure and Function

A QR code consists of black squares arranged in a square grid on a white background, which can be read by an imaging device such as a camera, and processed using Reed–Solomon error correction until the image can be appropriately interpreted. The required data is then extracted from patterns present in both horizontal and vertical components of the image.

Components

QR codes have several key components:

• Finder Pattern: Located at three corners of the QR code, it allows the scanner to recognize the code and determine its orientation.
• Alignment Pattern: Helps in correcting the distortion when the QR code is bent or curved.
• Timing Pattern: Alternating black and white modules that help the scanner determine the width of a single module.
• Version Information: Indicates the version of the QR code (from Version 1 to Version 40).
• Format Information: Contains information about the error tolerance and the mask pattern of the QR code.
• Data and Error Correction Keys: The actual data and the error correction keys.

Applications

QR codes are used in a wide range of applications, including:

• Product tracking
• Item identification
• Time tracking
• Document management
• General marketing

QR codes have become common in consumer advertising. Typically, a smartphone is used as a QR code scanner, displaying the code and converting it to some useful form (such as a standard URL for a website, thereby obviating the need for a user to type it into a web browser).

Advantages

QR codes have several advantages over traditional barcodes:

• They can store a large amount of data.
• They can be read from any direction (360 degrees).
• They have high fault tolerance due to error correction.

Related Technologies

• Barcode
• NFC
• RFID

See Also

• Barcode
• Data Matrix
• Aztec Code
• PDF417
• Semacode