DocumentCode :
1248961
Title :
Preconditioning for Edge-Preserving Image Super Resolution
Author :
Pelletier, Stéphane ; Cooperstock, Jeremy R.
Author_Institution :
Dept. of Electr. & Comput. Eng., McGill Univ., Montréal, QC, Canada
Volume :
21
Issue :
1
fYear :
2012
Firstpage :
67
Lastpage :
79
Abstract :
We propose a simple preconditioning method for accelerating the solution of edge-preserving image super-resolution (SR) problems in which a linear shift-invariant point spread function is employed. Our technique involves reordering the high-resolution (HR) pixels in a similar manner to what is done in preconditioning methods for quadratic SR formulations. However, due to the edge preserving requirements, the Hessian matrix of the cost function varies during the minimization process. We develop an efficient update scheme for the preconditioner in order to cope with this situation. Unlike some other acceleration strategies that round the displacement values between the low-resolution (LR) images on the HR grid, the proposed method does not sacrifice the optimality of the observation model. In addition, we describe a technique for preconditioning SR problems involving rational magnification factors. The use of such factors is motivated in part by the fact that, under certain circumstances, optimal SR zooms are nonintegers. We show that, by reordering the pixels of the LR images, the structure of the problem to solve is modified in such a way that preconditioners based on circulant operators can be used.
Keywords :
Hessian matrices; edge detection; image resolution; minimisation; Hessian matrix; circulant operator; cost function; edge-preserving image super resolution preconditioning; high-resolution pixel reordering; linear shift-invariant point spread function; minimization process; quadratic super resolution formulation; rational magnification factors; update scheme; Acceleration; Cost function; Equations; Image edge detection; Image restoration; Pixel; Strontium; Edge restoration; image super resolution (SR); preconditioning; regularization; Algorithms; Image Enhancement; Image Interpretation, Computer-Assisted; Pattern Recognition, Automated; Reproducibility of Results; Sensitivity and Specificity;
fLanguage :
English
Journal_Title :
Image Processing, IEEE Transactions on
Publisher :
ieee
ISSN :
1057-7149
Type :
jour
DOI :
10.1109/TIP.2011.2160188
Filename :
5898412
Link To Document :
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