1. An imaging system for imaging an object, the imaging system comprising: a projection data providing unit which includes a computer configured for providing acquired spectral projection data of an object comprising at least two components, a reconstruction unit which includes a computer configured for iteratively reconstructing at least two final component images of the object by performing several iteration steps, in which at least two intermediate component images reconstructed from the acquired spectral projection data are updated based on the acquired spectral projection data and a penalty term, which is indicative of a correlated noise between the at least two intermediate component images.