Moire-based auto-stereoscopic enhancement of images for duplex rendering on transparencies

摘要

Provided herein are teachings directed to using duplex printing on transparencies to create auto-stereoscopic enhancement to rendered images as 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 moiré pattern resulting due to halftone overlapping can be observed. On one side of the transparency is provided a uniform halftone with a selected median spatial frequency as printed. On the other side, the image for enhanced rendering consisting of two partitions is printed: that partition which is to be perceived as the background is printed using a halftone with spatial frequency equal to the median plus some delta x, while the other image partition is printed using a halftone with a spatial frequency equal to the median minus the same delta x. The spatial frequency difference between the halftones on two sides creates a corresponding shift-magnification factor M. The moiré 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 moiré stereoscopic pattern for the desired image partition as clearly discernable to the human eye with out aid of lenses or other means.