Method for duplex printing on transparencies to create auto-stereoscopic
enhancement to rendered images. 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 creates a
corresponding shift-magnification factor M with an amplified total depth
of the shift-magnification factor M times the thickness of the
transparency.