A method and system for image processing on nuclear medicine image data is disclosed. The image processing method comprises preparing a cutoff frequency table, which stores a relation between a parameter related to a radial intensity distribution of a spatial frequency of a nuclear medicine image and a Butterworth filter cutoff frequency. The method also comprises inputting and applying a two-dimensional Fourier transform to nuclear medicine image data in order to obtain a spatial frequency of the nuclear medicine image calculating a radial intensity distribution of the spatial frequency of the nuclear medicine image determining a cutoff frequency corresponding to a parameter related to the radial intensity distribution determined for the nuclear medicine image, with reference to the cutoff frequency table and filtering the nuclear medicine image data by means of a Butterworth filter set with the cutoff frequency.
