Method and apparatus for reconstructing image and medical image system employing the method

A material discrimination image generator, comprising:

• a receiver configured to receive a projection image for each energy band generated by passing an X-ray spectrum through an object to be inspected having at least one material;
• an initial image estimator configured to acquire an initial image for the at least one material based on the projection image;
• and
• an acquiring unit configured to acquire a material discrimination image for the at least one material by applying an image updating algorithm to the initial image.

A medial image system, comprising:

• a source configured to irradiate a multi-energy X-ray spectrum to an object to be inspected having at least one material;
• a material discrimination image processor configured to acquire a material discrimination image for each of the at least one material;
• and
• a final reconstruction image generator configured to generate a final reconstruction image by applying a reconstruction algorithm to a tomographic image including the acquired material discrimination image.