Inverse halftoning using wavelets

This work introduces a new approach to inverse halftoning using nonorthogon al wavelets. The distinct features of this wavelet-based approach are: 1) e dge information in the highpass wavelet images of a halftone image is extra cted and used to assist inverse halftoning, 2) cross-scale correlations in the multiscale wavelet decomposition are used for removing background halft oning noise while preserving important edges in the wavelet lowpass image, and 3) experiments show that our simple wavelet-based approach outperforms the best results obtained from inverse halftoning methods published in the literature, which are iterative in nature.