A detection values processing apparatus, the detection values processing apparatus comprising: - a detection values providing unit for providing detection values I b n, the detection values I b n being energy-dependent detection values, which are generated by a detector and which are indicative of radiation after having traversed an examination zone, the radiation being polychromatic radiation emitted by a radiation source and being filtered by a filter which comprises K-edge filter material having a K-edge within the energy range of the polychromatic radiation, - a component decomposition unit adapted to apply a component decomposition technique to the detection values for determining K-edge attenuation values A K n being first component attenuation values, which are indicative of an attenuation caused by the K-edge filter material, and additional component attenuation values, which are indicative of an attenuation caused by additional components of the examination zone, from the energy dependency of the detection values, the additional component attenuation values being second component attenuation values A P n A C n, which are indicative of an attenuation caused by a second component, and third component attenuation values A C n A P n, which are indicative of an attenuation caused by a third component, from the energy dependency of the detection values, wherein one of the second and third components is a photoelectric effect component of the examination zone for generating photoelectric effect component values and the other of the second and third components is a Compton effect component of the examination zone for generating Compton effect component values, - a reconstruction unit adapted to reconstruct an image of the examination zone from the additional component attenuation values and adapted to reconstruct an image of the examination zone from a combination of the second component attenuation values A P n A C n and the third component attenuation values A C n A P n, characterized in that the component decomposition unit is adapted to correct the photoelectric effect component values and the Compton effect component values in the examination zone with respect to a photoelectric effect and a Compton effect of the filter by a) subtracting from the photoelectric effect component values a product of the corresponding K-edge attenuation values A K n of the K-edge filter material and a provided ratio ( R KP) of photoelectric effect component values of the filter and the K-edge attenuation values A K n of the K-edge filter material and b) subtracting from the Compton effect component values a product of the corresponding K-edge attenuation values A K n of the K-edge filter material and a provided ratio ( R KP) of Compton effect component values of the filter and the K-edge attenuation values A K n of the K-edge filter material. - a detection values providing unit for providing detection values I b n, the detection values I b n being energy-dependent detection values, which are generated by a detector and which are indicative of radiation after having traversed an examination zone, the radiation being polychromatic radiation emitted by a radiation source and being filtered by a filter which comprises K-edge filter material having a K-edge within the energy range of the polychromatic radiation, - a component decomposition unit adapted to apply a component decomposition technique to the detection values for determining K-edge attenuation values A K n being first component attenuation values, which are indicative of an attenuation caused by the K-edge filter material, and additional component attenuation values, which are indicative of an attenuation caused by additional components of the examination zone, from the energy dependency of the detection values, the additional component attenuation values being second component attenuation values A P n A C n, which are indicative of an attenuation caused by a second component, and third component attenuation values A C n A P n, which are indicative of an attenuation caused by a third component, from the energy dependency of the detection values, wherein one of the second and third components is a photoelectric effect component of the examination zone for generating photoelectric effect component values and the other of the second and third components is a Compton effect component of the examination zone for generating Compton effect component values, - a reconstruction unit adapted to reconstruct an image of the examination zone from the additional component attenuation values and adapted to reconstruct an image of the examination zone from a combination of the second component attenuation values A P n A C n and the third component attenuation values A C n A P n, characterized in that the component decomposition unit is adapted to correct the photoelectric effect component values and the Compton effect component values in the examination zone with respect to a photoelectric effect and a Compton effect of the filter by a) subtracting from the photoelectric effect component values a product of the corresponding K-edge attenuation values A K n of the K-edge filter material and a provided ratio ( R KP) of photoelectric effect component values of the filter and the K-edge attenuation values A K n of the K-edge filter material and b) subtracting from the Compton effect component values a product of the corresponding K-edge attenuation values A K n of the K-edge filter material and a provided ratio ( R KP) of Compton effect component values of the filter and the K-edge attenuation values A K n of the K-edge filter material.