초록 ▼

A digital signal is imperceptibly embedded into an input source signal, such as an image or video signal, to produce an encoded (sometimes termed "watermarked") signal. The principle of quasi-rotational symmetry is employed to facilitate detection of the embedded signal notwithstanding rotation of t

A digital signal is imperceptibly embedded into an input source signal, such as an image or video signal, to produce an encoded (sometimes termed "watermarked") signal. The principle of quasi-rotational symmetry is employed to facilitate detection of the embedded signal notwithstanding rotation of the encoded signal. Single or multiple degrees of symmetry can be employed. In another aspect, the digital signal is transformed to a frequency domain and phase-only filtered prior to its combination with the input source signal. In an illustrative embodiment, this filtering operation helps hide the digital signal within the source signal, and facilitates detection of the embedded digital signal even after the encoded signal has undergone various forms of corruption.

대표청구항 ▼

[ I claim:] [1.] In a method of steganographically processing an image signal to embed multi-bit information therein, an improvement comprising representing said information in the form of a plurality of partially overlapping quasi-rotationally symmetric patterns, and processing the image signal to

[ I claim:] [1.] In a method of steganographically processing an image signal to embed multi-bit information therein, an improvement comprising representing said information in the form of a plurality of partially overlapping quasi-rotationally symmetric patterns, and processing the image signal to imperceptibly enabled said plurality of partially overlapping quasi-rotationally symmetric patterns therein, wherein said quasi-rotational symmetry of the patterns facilitates detection of the multi-bit information from a resulting processed image signal if said processed image signal is corrupted by scaling or rotation operations.