2 d barcodes(nsm)

Pervasive 2D Barcodesfor Camera Phone

Applications

History• 2000– CyberCode1, Sony, visual tagging augmented reality– J-SH09, J-Phone - QR Code: 1-D and 2-D phone

• QR Code Blog• URLS• Email addresses• Shopping• Public Transport Schedules and Events• Air Line Ticketing• Coke Promotions• Food-history information service

Motivation: How well do they work?

• Omnidirectional symbol reading• Support for low-resolution cameras• Reading robustness under different lighting

conditions• Barcode reading distance• Error correction capability• Security• Support for multiple character sets• Data capacity

Study

• 30 2D barcodes are in use, 6 studied• database 2D barcodes = initially industrial– QR Code – VSCode– Data Matrix

• Index-based 2D barcodes = invented for phones– Visual Code– ShotCode– ColorCode

Denso Wave QR Code - 1994

Position detection patterns, located at three ofsymbol’s corners

3 Position detection

Data Contents

• QR Code can encode all types of data including symbols, binary data, control codes, and multimedia data. The maximum data capacities are

• 7,089 characters for numeric data, • 4,296 characters for alphanumeric data, • 2,953 bytes for binary data, and • 1,817 characters for Japanese Kanji and Kana

data.

Comparison with 1-D Bar Code

Solomon Reed Encoding

Redundancy

• Level L approximately 7 percent,• M approximately 15 percent• Q approximately 25 percent• H approximately 30 percent

Code can be decomposed into smaller patterns

Veritec VSCodeBiometric data for access-control applications. 4,151 bytes

Data Matrix

• 1,556 bytes

Visual Code

• HCI using camera phones 83 bits –mouse

ShotCode

Ternary Code

102011221210001

Original Spot Code

ColorCode

• 10 digits matrix of 5 cells rendered— black, blue, green, and red.

• error parity check that detects any incorrect color recognition and corrects it

• 40 percent visibility

Results

Results

• Resolution not so important• 2D barcodes (21.7 cm) >• index-based 2D-barcodes (16.9 cm)