title: Three-dimensional volume containing multiple two-dimensional information patterns.
abstract: We have developed an algorithm for recording multiple gradated two-dimensional projection patterns in a single three-dimensional object. When a single pattern is observed, information from the other patterns can be treated as background noise. The proposed algorithm has two important features: the number of patterns that can be recorded is theoretically infinite and no meaningful information can be seen outside of the projection directions. We confirmed the effectiveness of the proposed algorithm by performing numerical simulations of two laser crystals: an octagonal prism that contained four patterns in four projection directions and a dodecahedron that contained six patterns in six directions. We also fabricated and demonstrated an actual prototype laser crystal from a glass cube engraved by a laser beam. This algorithm has applications in various fields, including media art, digital signage, and encryption technology.
authors.affiliation: Graduate School of Engineering, Chiba University, Chiba, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Nakayama
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shiraki
authors.forename: Ryuji
authors.initials: R
authors.lastname: Hirayama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Masuda
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Shimobaba
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Ito
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D007834:Lasers