Nonlinear resampling for edge preserving moire suppression

Printing applications using classical halftoning need to resample the origi nal image to a screen lattice. This resampling can cause undesirable moire artifacts in the screened image. Some printing techniques, e.g., gravure pr inting, are highly susceptible to moire, not only because of the low resolu tion screen lattices they employ but also because the degree of freedom in constructing half-tone dots is limited by the physical constraints of the e ngraving mechanism. Current resampling methods compute new samples by simpl e interpolation techniques that cannot prevent sampling moire very well. Th erefore precautions against moire have to be made in the prepress phase, wh ich is not practical and sometimes not feasible. A novel technique is prese nted to adaptively resample an image on the screen lattice using a local es timate of the risk of aliasing. The purpose is to suppress moire while main taining the sharpness of the image. Experimental results demonstrate the fe asibility of the proposed approach. (C) 2000 SPIE and IS&T. [S1017-9909(00) 01904-8].