An X-ray detector includes a detection unit to convert X-rays into a signal value and an evaluation unit. The detection unit and the evaluation unit are configured in a common component, the extent of the component along a first direction being not greater than the extent of the detection unit. The evaluation unit includes at least one correction unit to correct the signal values, a computation unit to control the correction, and a memory unit to store at least one correction parameter. The evaluation unit is designed such that the signal values are corrected as a function of the at least one correction parameter. A method and detector group are also disclosed.
