Patent ID: 7706025

Claim:
A moiré-based auto-stereoscopic digital watermark system, comprising: a substantially transparent substrate having a first side; a first substrate applied marking material having a uniform periodic structure at a first frequency, as applied to and placed on the first side of the substantially transparent substrate to thereby provide a decoder overlay; a second substrate and, a second substrate applied marking material as applied to a surface of the second substrate, the second substrate applied marking material further comprising an image of interest with a first contiguous partition and a second contiguous partition that is separate from the first partition, the first contiguous partition having a first periodic structure at a second frequency, that second frequency being related to but some delta away from the first frequency, and the second contiguous partition that is distinct from the first contiguous partition and having a second periodic structure at a third frequency, the second periodic structure being substantially parallel to the first periodic structure, that third frequency being related to and a first delta away from the first frequency and a second delta way from the second frequency where the first delta is different than the second delta, such that when the decoder overlay is placed first side facing up upon the second substrate in substantial alignment with the second substrate applied marking material, a moiré-based auto-stereoscopic digital watermark image comprising both the first contiguous partition and the second contiguous partition is evident, wherein both the first contiguous partition and the second contiguous partition of the moiré-based auto-stereoscopic digital watermark image are simultaneously evident as a moiré-based auto-stereoscopic digital watermark image to an observer.