1. A method for calibrating an image-generated x-ray system, comprising a digital x-ray receiver that receives x-ray radiation emitted from an x-ray tube, comprising the steps of: (a) generating a first dark raw image at a first constant reference temperature of the x-ray receiver; (b) for each of a plurality of first dose settings of said x-ray tube at said first reference temperature, generating a first bright raw image; (c) automatically electronically determining a plurality of first offset-corrected bright images from the dark raw image and the respective first bright raw images; (d) at each of a plurality of second reference temperatures, generating a second dark raw image; (e) for each of the second reference temperatures, generating a second bright raw image at a second dose setting of said x-ray tube that corresponds to one of said first dose settings; (f) for each of the second reference temperatures, automatically electronically determining an offset-corrected second bright image from the second dark raw image and the second bright raw image; (g) for each reference temperature, automatically electronically determining at least one quotient image from the second bright image and the first bright image for the second dose setting; and (h) storing the respective quotient images linked with the respective reference temperatures used to determine the respective quotient images.