The invention provides novel scale-based filtering methods that use local structure
size or "object scale" information to arrest smoothing around fine structures and
across even low-gradient boundaries. One method teaches a weighted average over
a scale-dependent neighborhood; while another employs scale-dependent diffusion
conductance to perform filtering. Both methods adaptively modify the degree of
filtering at any image location depending on local object scale. This permits a
restricted homogeneity parameter to be accurately used for filtering in regions
with fine details and in the vicinity of boundaries, while at the same time, a
generous filtering parameter is used in the interiors of homogeneous regions.
