Title :
Regularity-preserving image interpolation
Author :
Carey, W. Knox ; Chuang, Daniel B. ; Hemami, Sheila S.
Author_Institution :
Sony Electron. Inc., San Jose, CA, USA
fDate :
9/1/1999 12:00:00 AM
Abstract :
Assumptions about image continuity lead to oversmoothed edges in common image interpolation algorithms. A wavelet-based interpolation method that imposes no continuity constraints is introduced. The algorithm estimates the regularity of edges by measuring the decay of wavelet transform coefficients across scales and preserves the underlying regularity by extrapolating a new subband to be used in image resynthesis. The algorithm produces visibly sharper edges than traditional techniques and exhibits an average peak signal-to-noise ratio (PSNR) improvement of 2.5 dB over bilinear and bicubic techniques
Keywords :
image processing; interpolation; wavelet transforms; average peak signal-to-noise ratio; bicubic techniques; bilinear techniques; decay; edges; image continuity; image resynthesis; oversmoothed edges; regularity; regularity-preserving image interpolation; subband; wavelet transform coefficients; wavelet-based interpolation method; Filtering; Finite difference methods; Image enhancement; Interpolation; Maximum a posteriori estimation; Nonlinear filters; PSNR; Polynomials; Spline; Wavelet transforms;
Journal_Title :
Image Processing, IEEE Transactions on
