For the purpose of noise correction for an x-ray flat-panel detector (2) it is firstly provided that in the dark image--without radiation impinging on the detector panel (4)--the noise is recorded for the subareas of an active area (8) and from this, subarea-specific correction factors are determined by means of which the respective signal value of the respective subarea is corrected in imaging operation. A dark area correction factor (DF1, DF2) is also determined in each case from the noise of two dark areas (6) that are spaced apart with respect to each other. In order to determine subarea-specific signal correction factors (SK), each of the DA correction factors (DF1, DF2) is weighted with a subarea-specific weighting factor (g1, g2), in particular a distance factor (a). By means of said measure improved noise correction is achieved.