Abstract: A method for setting a control variable of a filter for noise reduction in medical images is provided. Image data of the medical images is classified into at least one noise region and at least one structure region. A variance measurement is performed either for all the image pixels or a subset of them to determine the edge thicknesses. A histogram is generated from the edge thicknesses. The maximum of the histogram is determined and a Gaussian curve is fitted to the histogram. A threshold value for noise and structure is determined as a function of the standard deviation of the Gaussian curve. The noise and structure are measured in the regions. The standard noise and structure deviations are determined and compared. The control variable is setup as a function of the comparison of noise and structure. The invention can be used for reduction of temporal noise in bandpass images.