METHOD AND SYSTEM OF IMAGE RECONSTRUCTION AND METHOD AND SYSTEM OF IMAGE CONSTRUCTION

A method of image reconstruction is provided. When an object is not placed in a measurement space, first intensity images of an electromagnetic wave passing through the measurement space and corresponding to photon energy levels are measured. When the object is placed in the measurement space, second intensity images of the electromagnetic wave passing through the object and corresponding to photon energy levels are measured. In a database, data including an attenuation coefficient of each substance respectively having components irradiated by the electromagnetic wave corresponding to each photon energy level and a thickness of each substance in a transmission direction of the electromagnetic wave corresponding to each photon energy level are provided. Attenuation images of the object respectively corresponding to the components are calculated according to the data and the first and second intensity images. An image reconstruction system and a method and system of image construction are also provided.