A method for neutralizing the non-noise correlated, multiplicative image-artifacts introduced by the X-ray exposure, the detector or the digitizer prior to the determination of the Signal-to-Noise Ratio or the (Normalized) Noise Power Spectrum in CR/DR radiography systems. This method uses statistical techniques and the photon-noise physical model to correct the raw, digital image-data obtained in the selected region of interest (roi) for evaluation during quality control (QC).