Method for duplex printing on transparencies to create auto-stereoscopic
images. 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 one side of the transparency is provided a uniform
halftone with a selected median spatial frequency as printed. On the
other side, the printing consists of two partitions: what is to be
perceived as the background is printed using a halftone with spatial
frequency equal to the median plus some delta x, while a desired image
partition is printed using a halftone with a spatial frequency equal to
the median minus the same delta x. The spatial frequency difference
creates a corresponding shift-magnification factor M with an amplified
total depth of the shift-magnification factor M times the thickness of
the transparency.