Re: How are x-ray images processed by computer?

Vivek,

Your question is an interesting idea but has a fairly significant problem.
It also crosses several different fields: physics, medicine and computer
science.

What you suggest is like splitting color film into the different layers and
extracting information from the different color layers. Color film has
three layers for red, green and blue. If you are really careful you can
split the film with a razor blade. Commercially it is called a color
separation. If you are not so careful, you can split your fingers. The
usual warnings about sharp objects and adult supervision apply.

The problem is that X-rays use a very narrow range of wavelengths (colors)
and black and white film. The normal X-ray source uses the Aluminum K lines
for the source. The information doctors gain from an X-ray comes from the
average absorption through the entire path through the subject. The fairly
recent introduction of CAT scans decomposes the absorption of small regions
of the subject by taking very many X-rays from many directions. Search on
“tomography” for a more detailed discussion on the methods used. Tomography
is used is fields other than medicine. Geophysics uses it to model both
absorption and the velocity of sound through the earth. 

In short, your project requires a “white” source and “color” film in the
X-ray region in conjunction with a tomographic solution of the resulting
pictures. These are rather difficult to achieve. 

David