Abstract

We propose a watermarking scheme for hardcopy pictures based on computer-generated holography. A hologram of the watermark is produced using a conjugate-symmetric extension technique, and its spectrum is inserted into the discrete cosine transform domain of the image. Adjusting the watermark placement in a data array, a trade-off between transparency and robustness is achieved. Anticropping and the interference-resisting capability of holograms make the watermark robust against manipulations commonly performed on digital images during postprocessing, including contrast enhancement, moderate smoothing and sharpening, and, in particular, geometric transformation. Most importantly, the proposed hologram-based watermarking can withstand the printing-scanning attack and, therefore, is useful in protecting copyright of digital photographs both as electronic and hardcopy versions.

© 2010 Optical Society of America

Full Article  |  PDF Article

References

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Figures (9)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Tables (3)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Equations (6)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription

Metrics

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access OSA Member Subscription