In the present invention, subband signals are obtained by performing multiresolution decomposition on image data by using a broad-sense pinwheel framelet that is a set of an approximate filter with no orientation and a plurality of detail filters with respective orientations, and that has a degree. When an image is reconstructed by summing the obtained subband signals, the reconstructed image data is generated by attenuating or amplifying a subband signal corresponding to at least one of filters that have predetermined frequency characteristics and/or a predetermined orientation among the filters.