2 d barcodes(nsm)
DESCRIPTION
About barcodeTRANSCRIPT
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)