Method and apparatus for decomposing low- density material and method and apparatus for obtaining attenuation correction image based on dual-energy technique

A dual energy technique based material decomposing apparatus, comprising:

• a memory which stores one or more programs to decompose a material based on a dual energy technique;
• and
• one or more processors which perform an operation of decomposing a material based on a dual energy technique by one or more programs stored in the memory,
• wherein the processor is configured to obtain intensity change information between a radiographic image of a decomposition material phantom formed of a first material and a second material to be decomposed and a radiographic image of an equivalent material phantom formed of a first equivalent material and a second equivalent material corresponding to the first material and the second material, respectively, using a simulated radiographic imaging system, convert an image intensity of the equivalent material phantom using the intensity change information from a dual energy image, obtain a material decomposition constant based on the dual energy image with a converted image intensity, and decompose the first material and the second material from a dual energy image of an object including the first material and the second material using the material decomposition constant.