ROBUST TECHNIQUE FOR IMAGE DESCREENING BASED ON THE WAVELET TRANSFORM

In this correspondence, a novel wavelet-based approach to recover cont inuous-tone (contone) images from halftone images is presented. Wavele t decomposition of the halftone image facilitates a series of spatial and frequency selective processing to preserve most of the original im age contents while eliminating the halftone noise. Furthermore, option al nonlinear filtering can be applied as a postprocessing stage to cre ate the final aesthetic contone image. This approach lends itself to p ractical applications since it is independent of parameter estimation and, hence, universal to all types of halftoned images, including thos e obtained by scanning printed halftones.