Moire-based autostereoscopic images by duplex printing on transparencies

摘要

In this paper we describe a method using duplex printing on transparencies to create auto-stereoscopic images viewed in a "see-through" manner. By choosing different halftone structures, differing by having different spatial frequencies for each of the two sides of a transparency, a moire pattern resulting due to halftone overlapping can be observed. On oneside of the transparency is provided a uniform halftone with a selected median spatial frequency f. On the other side, theprinting consists of two partitions: what is to be perceived as the background is printed using a halftone with spatial frequency equal to the median frequency f plus some Δf, while a desired image partition is printed using a halftone with a spatial frequency equal to the median frequency f minus the same Δf The spatial frequency difference between the halftones on two sides creates a corresponding shift-magnification factor M. The moire produced by the two partition print images as visually located appear in two separate spatial planes as separated by the transparency, with an amplified total depth of the shift-magnification factor M times the thickness of the transparency. This yields a moire stereoscopic pattern for the desired image partition as clearly discernable to the human eye with out aid of lenses or other means.