A method of image reconstruction is provided. When the object is not disposed in a measurement space, a plurality of first intensity images of an electromagnetic wave passing through the measurement space respectively corresponding to a plurality of photon energy levels are measured. When the object is disposed in the measurement space, a plurality of second intensity images of the electromagnetic wave passing through the object respectively corresponding to the photon energy levels are measured. Data in a database is provided, and the data includes an attenuation coefficient of each of a plurality of substances respectively having a plurality of components irradiated by each of electromagnetic waves corresponding to the photon energy levels and a thickness of each of the substances in a transmission direction of electromagnetic waves corresponding to the photon energy levels. A plurality of attenuation images of the object respectively corresponding to the components are calculated according the data, the first intensity images and the second images. A image reconstruction system and a method and system of image construction are also provided.一種影像重建方法。在量測空間無配置待測物時量測通過量測空間的電磁波分別在多個光子能量下的多個第一強度影像。在待測物設置於量測空間時量測通過待測物的電磁波分別在這些光子能量下的多個第二強度影像。提供資料庫的資料,此資料包括分別具有多個成分的多個物質中的每一個物質在每一光子能量所對應的電磁波照射下的衰減係數及每一物質在光子能量所對應的電磁波傳遞方向上的厚度。根據資料、多個第一強度影像、多個第二強度影像計算出待測物分別對應於這些成分的多個衰減量影像。一種影像重建系統及影像建構方法與系統亦被提出。S100、S110、S120、S200、S210、S220、S300、S310、S320、S321、S322、S323、S324‧‧‧步驟
