Regularity-preserving image interpolation

Assumptions about image continuity lead to oversmoothed edges in common ima ge interpolation algorithms. A wavelet-based interpolation method that impo ses no continuity constraints is introduced. The algorithm estimates the re gularity of edges by measuring the decay of wavelet transform coefficients across scales and preserves the underlying regularity by extrapolating a ne w subband to be used in image resynthesis. The algorithm produces visibly s harper edges than traditional techniques and exhibits an average peak signa l-to-noise ratio (PSNR) improvement of 2.5 dB over bilinear and bicubic tec hniques.