Although barcodes can be used to manage data conveniently, they cannot be applied to small areas. Therefore, pointcodes are used to overcome the issue in this article. A pointcode uses a pointcode pattern to encode data and uses a pointcode image to decode data. A pointcode pattern is composed of many grating dots with different specified grating pitches and grating orientations. Moreover, there are two grating-dot sizes generated. When a laser beam illuminates a pointcode pattern with correct illuminating conditions, a pointcode image corresponding to the hidden data is diffractively reconstructed. A pointcode image is composed of many bright points with different positions. There are two possible bright-point sizes generated. A bright point or two bright points at specified positions are used to denote a number. Small pointcode patterns are enough to diffractively form pointcode images.
© 2009 Optical Society of America
Optical Data Storage
Original Manuscript: September 17, 2009
Revised Manuscript: November 9, 2009
Manuscript Accepted: November 10, 2009
Published: December 11, 2009
Sheng Lih Yeh, Hung Jen Yang, Shyh Tsong Lin, and Ming Wei Wu, "Replacers of barcodes for small application areas by using grating dots to diffractively form bright points," Appl. Opt. 48, 6940-6945 (2009)