about gray scale images for 3d

Hi all
I seen the gray scale image which can generate 3D relief
easily.
http://members.aol.com/tukuvectors/grayscale.html
I was very interested but its'the hi-rez gray scale images
and not the software to make the images.

for example:
white=5.00mm
black=0.00mm
gray =0.01-4.99mm
Aren't there any someone
found in the software which made transforming color into
height?
thanks,