Color from B&W

[P3D Jonathan Orovitz <jorovitz@xxxxxxxxx>]

Some recent posts discussed pairs of B&W pictures in stereo slide mounts
from which, one could derive color images.  Polarizers have nothing to
do with the color except that the inventor of polarizers documented this
phenomenon forty years ago.

Edwin Land was the father of instant photography and perhaps godfather
of stereo photography (polarizers).  He was very interested in optics
and human color perception.   Doctor Land knew that conventional color
theory depended upon images made from primary colors additive or
subtractive).  Land once said, "When the experiment doesn't work,
distrust the experiment; when the experiment works, distrust the
theory." 

Land, like painter Josef Albers, Land knew that human color perception
was subjective.  From this, Land developed his Retinex theory of color
perception.  His color perception experiments were reported in
Scientific American around 1960.  In one experiment, he took two
identical B&W photos.  He used a yellow filter in front of the lens in
one of them.  Using two projectors, he projected them, superimposed, on
a screen, using the same yellow filter over the projector lens showing
the filtered image.  He was able to see all colors, though some were
subdued.

While the Retinex theory has found considerable use in image processing,
I am not aware that the full color from two B&W images experiment has
produced anything commercially useful.

Jon Orovitz


------------------------------