An electrical charge signal such as this is produced on absorption of X-ray quanta by way of directly converting materials, for example semiconductors such as GaAs, CdTe, CdZnTe or photoconductors such as Se, PbI2 or PbO. The device for processing expediently has a device for setting the number of subpixels which form one pixel, and/or for selection of the number of subpixels to be used per pixel